Investigating Minds 2009 TB

ADHD and Rewar-- Hey, look! A squirrel!

2009-04-28T05:50:00.000-07:00

ADHD and Dopamine
The current, generally accepted belief is that ADHD (attention deficit/hyperactivity disorder) is caused by a dopamine imbalance within the brain. However, there is controversy as to whether ADHD is caused by hypodopaminergic functioning or hyperdopaminergic. There are several reasons for this theory. First of all, amongst other things, dopamine is often related to attention and motivation. Another reason is due to the effectiveness of methylphenidate based medication (a.k.a. meth salts). Methylphenidate acts as an dopamine reuptake inhibitor by blocking dopamine transporters. Thus there is more dopamine in the neurons, but the dopamine fires less often.

CD and ADHD
Conduct disorder (CD) is characteristic of socially disruptive, aggressive and usually destructive behavior. Destructive not only to property and others, but to one's own daily life. ADHD is very similar to CD, except there tend to be far less violent tendencies, if any. However, like CD, ADHD can be inhibit one's academic career, occupation, or even social ability. It is believed that CD and ADHD are in essence the same on a neurobiological level, and the only difference comes in upbringing. Individuals who grow up in a high-risk environment are more likely to develop CD rather than ADHD, and visa-versa for a low risk environment. Indeed, the two are so similar that CD is classified as a type of ADHD.

Objective
The objective of Gatzke-Kopp et al's experiment was to try and determine whether ADHD/CD and thus other externalizing disorders such as antisocial personality disorder and borderline personality disorder. The original objective was to compare neurological differences between people with CD and ADHD when dealing with rewards and reward anticipation, however it rather quickly became apparent that this would not be possible since ADHD and CD were so similar. A reward based approach was used because both ADHD and CD are often characterized by impulsivity, that is, the inability to defer gratification, even if doing so will result in a greater reward. In the end, it was decided to use a control group of individuals with no mental disorders. Only males were used because of the small sample size.

Procedure
A sample of twenty-one males between the ages of twelve and sixteen with ADHD/CD were chosen as the experimental group. This was later reduced to nineteen because two of the participants were unable to stay still enough for long enough. A control group of eleven males of the same ages with no mental disorders was also chosen. Any individuals taking any sort of stimulant medication were asked to dis continue use at least thirty-six hours before the test. Previous experiments have shown that there is no appreciable difference between individuals with ADHD who have never taken stimulants, and one who has stopped taking them for thrity-six hours.
Both groups were asked to play three rounds of a simple game. A green square was flashed for 1.2 seconds on either the left or right side (chosen psuedorandomly). The participant would then have to press the appropriate button. If the answer was correct, and a monetary reward was given, then a tone was played for half a second; if the answer was correct, and no reward was given, then a different tone was played for half a second. If the answer was incorrect, then there was no adverse affect.
The game had three rounds. The first round any and all correct answers resulted in a forty cent reward. In the second round, no money was ever rewarded, and in the final round, money was rewarded only part of the time.

Results
The results from the fMRI showed that during the first round when a monetary reward was given, both the control group and the experimental group showed increased activity in their striatum in both the left and right hemispheres. The striatum is a part of the basal ganglia, and is most often associated with motor functions (e.g. movement planning), however, it also deals with executive functioning, reward anticipation, and the processing of unique or novel stimuli. The area is also comprised mainly of medium spiny neurons, which are heavy with dopamine (figure 1).
However, during the non-monetary portion, the control group's anterior cingulate cortex (ACC) was highly activated, however, in the experimental group, the striatum continued to be highly activated. Amongst other things the ACC is used for motivation, task anticipation and error detection. (figure 2 and figure 3)

Conclusions
Ultimately, the experiment did not resolve the hypodopaminergic versus hyperdopaminergic debate. While is is true that dopamine is far more prevelant in the striatum than the ACC, there is no garantee that the neurotransmitter being used is indeed dopamine, since fMRI's can only detect brain activity and not which neurotransmitter is being used.
However, this experiment can give us a great deal of insight into other symptoms of ADHD/CD. The activation of the striatum may help explain the impulsivity of individuals with ADHD/CD. Because the striatum is involved with reward anticipation, its continued activation could mean that the anticipation in someone with ADHD/CD is much greater than in a normal individual, and thus much harder to resist.
It is also interesting to note the lack of activation of the ACC. The ACC is important for error detection and error correction, and thus reinforcement learning (i.e. learning from ones mistakes). This could explain, at least to some degree, why people with ADHD are often disturbing, since they would not have learned to control themselves despite being scolded; perhaps more obviously, though, it may help explain the aggressive tendencies, usually socially related, of individuals with CD in a similar, but more pronounced, way it explains the ADHD disruptive behavior.

References
Gatzke-Kopp, Lisa et al. Neurological Correlates of Reward Responding in Adolescents With and Without Externalizing Behavior Disorders. Journal of Abnormal Psychology. Vol. 18 N.1(2009)

Wikipedia. "File:Dopamineseratonin.gif". http://en.wikipedia.org/wiki/File:Dopamineseratonin.gif

Wikipedia. "Methylphenidate". http://en.wikipedia.org/wiki/Methylphenidate

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC, American Psychiatric Association, 2000.

2009-04-27T15:53:00.000-07:00

Could LSD cure your OCD?

(Could 'shrooms' make you less afraid of death?)

When a person is diagnosed with terminal cancer it can result in a drastic change in their behavior as well their outlook on life. Often times the fear of death will overwhelm a patient and they will suffer from chronic depression and anxiety. In 2001 the National Cancer Policy Board of the Institute of Medicine released a search for “novel” approaches to palliative treatment. Palliative treatment is the search for a type of medical care that alleviates or reduces a patient’s emotional and psychological suffering as a result of their terminal illness. Dr. Charles Griffiths, of John Hopkins University responded to this search. He suggested an exploration of the hallucinogenic drug Psilocybin. His hope was that the experience on this drug would reduce a person’s anxiety about their impending death as well as minimize their desire for pain medication. Although the drug will not lessen the physical pain caused by the illness, Girffiths suspects that the patient’s attitude and outlook will change dramatically as a result of the experience, ensuing in a changed perception of their pain.

PSILOCYBIN AND ITS EFFECT ON THE BRAIN:

Psilocybin is a hallucinogenic drug found in psilocybin mushrooms (commonly called ‘magic mushrooms’ or ‘shrooms’). Hallucinogens are generally divided into two groups of alkaloids, tryptamines: including drugs such as Psilocybin, DMT and LSD and phenthylamines: such as mescaline. Tryptamines are a type of alkaloid, generally found in plants, animals and fungi. Hallucinogens, such as Psilocybin have been present in religious ceremonies for hundreds of years. Generally these drugs are restricted by indigenous cultures for highly ritualized sacramental and healing ceremonies.

Psilocybin has the ability to profoundly change one’s state of consciousness. Effects of consumption may include a distorted perception resulting in somatic, visual, olfactory, gustatory and auditory hallucinations. Consumption may also produce a synthesis of random sensory experiences such as ‘tasting colours’. The effects listed are common in serotonergically mediated hallucinogens. These are those receptors that exert their influence on the same receptors that respond to serotonin. The brain receptor that is affected by Psilocybin is called 5-HT2A which is widely dispersed throughout the central nervous system, specifically in serotonin rich areas such as the prefrontal, parietal and somatosensory cortex. Hallucinogens such as LSD and Psilocybin act as full/partial agonists at this receptor, causing an increase in this receptors activity.

Fig.1 The distribution of Serotonin in the brain.

Psilocybin and other hallucinogens are proven to stimulate specific areas of the brain. PET scans show the prefrontal cortex and the amygdala are affected by Psilocybin. The effect on the amygdala explains the heightened emotions one experiences on a Psilocybin 'trip', the prefrontal cortex is responsible for our executive functions and this explains effects on our personality and on our ability to organize thoughts and actions.
There is a great deal of speculation that the thalamus is intensely affected by hallucinogens. The thalamus is a relay station for the previously mentioned 2HT serotonin receptors. It is also responsible for receiving auditory, somatosensory and visual sensory signs. It then sends these sensory signals to the cerebral cortex. If the thalamus were overwhelmed, it may no longer be able to filter through the sensory information properly. This would mean that the prefrontal cortex would be inundated with sensory information. This avalanche of sensory data may be what leads to changes in our behaviour and perception.

Fig. 2 Shows the activation sequence for motor activity and demonstrates the thalamus and its role with the aspects of the prefrontal cortex.

THE STUDY:

Griffiths’s desire was to research whether profound activation of the serotonin receptor could result in what is considered a primary mystical experience. He also wanted to study whether this experience could have lasting effects on a patient’s attitude toward their illness and their fate. Griffiths organized a double blind study comparing the effects of orally administrated Psilocybin and Methylphenidate (often referred to as Ritalin, a psycho-stimulant prescribed for ADHD and narcolepsy that has a similar onset and duration as Psilocybin).

The study involved two or three 8 hour drug sessions conducted at 2 month intervals. Thirty-six volunteers aged between twenty-four and sixty-four years were involved. Volunteers were all physically and psychologically healthy, had no previous experience with hallucinogens and were affiliated with some sort of religion/spirituality. Participants were required to have religious/spiritual connections because Griffiths felt it would, “better equip volunteers to understand and consolidate any mystical-type experiences they might have in the study.” Thirty of the thirty-six participants were divided into two groups. On their first drug session the group received a dose of either Methylphenidate or Psilocybin, the alternative drug was administrated to them during their second session. The 8hr drug sessions were conducted in a room designed to replicate a living room.

http://www.blogsforcompanies.com/TTimages/psilocybin_research_study.jpg

Fig.3 The location used for the experiment, a room made to look like a living room.

This comfortable space was to ensure physical safety and a relaxing environment that would not seem threatening in case of hallucinations/perceptual changes. During each drug session the participant was accompanied by two monitors. Sessions were videotaped and participants were encouraged to listen to music, lie down on a couch and wear an eye-mask. In order to decrease the effects of this “expectancy” both the monitor and the subject were “blinded” to what drug was being consumed. Not only that, but a ‘red herring’ group of 6 participants who only received a placebo, but were informed that they had consumed Psilocybin on their third drug session, were a part of the study.

RESULTS:

The study was designed so that measures were taken, during the drug session, 7 hours after ingestion, two months after ingestion and finally, 14 months after their first Psilocybin trip. The 2 month and 14 month follow up survey assessed altered states of mind, sensitivity to hallucinogen, the scale of one’s mystical experience, changes in attitude and behaviour, spiritual transcendence and personality factors such as neuroticism and openness. Finally, three adults who had been submitted by the participant answered a questionnaire on the participant’s behavior since the experiment.

The most striking result from the survey done 7 hours after drug ingestion, was from the measure of mystical experience questionnaire. This showed that 22 of the 36 volunteers fulfilled the criteria for a ‘complete mystical experience’ as defined by Pahnke and Richards. Findings from the questionnaire 2-months after the drug was ingested express that Psilocybin significantly increased ratings of mood, behaviour, positive attitude and social effect. Sixty seven percent of the participants went on to list their experience on Psilocybin to be one of the most meaningful experiences of their lives or among the top five most meaningful experiences they have ever had.

http://csp.org/psilocybin/Hopkins-CSP-Psilocybin2008.pdf

Fig. 4 Graphs demonstrating results from the 2 month survey and the 14 month survey, comparing the Psilocybin experience and effects with the Methylphenidate experience and effect.

The 14 month follow up survey showed that 64% of the patients indicated the experience as increasing their life satisfaction and well being moderately or very much. Furthermore, 61% described the experience as being associated with significant or extreme, positive changes in behaviour and attitude, since the first session. Since the Psilocybin experience, the volunteers rated low on neuroticism and negative affect and high on extroversion, openness, agreeableness and measure of actualization potential, this rating is based on adult norms. Quotes from the verbatim study that was taken included:

The experience expanded my conscious awareness permanently...I accept 'what is', more easily.

That in every horrible or frightening experience, if you stay with it, enter into it, you will find God...It has become a guiding principal in my life.

I experienced the utter joy of letting go-without anxiety-without direction-beyond ego.

WHAT THIS MEANS:

These results certify that under the correct conditions, Psilocybin is able to be administered safely and that it will successfully produce occurrences similar to spontaneous mystical experiences. The information also confirms that these experiences have a proven long-term positive effect on the lives of participants. Griffith’s hope is to continue his research as this study is only at its preliminary stages. Already, the search for terminal cancer patients, suffering from depression and anxiety and willing to try Psilocybin has begun. He is also hopeful that this drug may aid in treating drug dependency. This is partially inspired by a Canadian study, from the 60’s, that attempted (with some success) to cure alcoholism with Mescaline and LSD.

Griffiths also wishes to investigate the importance of using volunteers with some sort of religious/spiritual connection in order to successfully achieve a ‘mystical experience’ that has long-term effects. Not only does this experiment aid Dr. Griffiths’ own research but it also is helping to re-open the exploration of psychedelic drugs and their potential for the medical world. Studies of these drugs have been off limits for the last few decades, due to their role in the 60’s counter culture, but with the success of experiments like this one, other more radical experiments are being approved, such as a study at UCLA researching LSD and if it could help people with extreme cases of OCD.

2009-04-27T11:56:00.000-07:00

Brain Abnormality Found In Boys With Attention Deficit Hyperactivity Disorder

Lie To Me

2009-04-25T10:28:00.000-07:00

Background

Relevant Parts of the Brain

Anterior Cingulate Cortex:

Connected with the prefrontal and parietal cortex
Regulates autonomic function including blood pressure and heart rate
Also involved in rational cognitive functions such as reward-anticipation, decision making, empathy and emotion

Dorsal Lateral Prefrontal Cortex:

Responsible for motor planning, organization and regulation
Associated with Working-memory; the storage and manipulation of information

The Parietal Cortex:

Determination of spatial sense and navigation

The Polygraph

Inadmissible in court
Federal Polygraph Handbook:
Question Form - Be clear and concise; Avoid legal terms when possible; Be constructed so that they may be answered yes or no; Not be worded in the form of an accusation or contain an inference that presupposes knowledge or guilt; In specific issue tests when testing for multiple items or amounts of money, use the phrase, "any of', e.g., "Did you steal any of that money?"; In specific issue tests, only address one issue in each question; In specific issue tests, only address one incident in each series.

Question Type - Primary Relevant. This question tests the possible direct involvement of the examinee. In PDD screening questioning formats, all relevant questions are considered primary relevant questions;
Secondary Relevant. This question tests the examinee's possible involvement in the
offense under investigation. A secondary relevant question should be constructed to address a secondary issue such as help, plan, or participate; test for secondary involvement in, such as seeing, hearing, or knowing; or focus on the nature or location of evidence and/or physical acts that support the primary offense. There are three types of secondary relevant questions:
1. Evidence-Connecting. An evidence-connecting question is designed to
determine if the examinee was involved with any of the evidence of the crime or is aware of the nature or location of various items of evidence.

Do you know where any of that money is now?
2. Guilty-Knowledge. A guilty-knowledge relevant question is used to determine
if the examinee has any knowledge of who committed the incident under investigation.

Do you know who stole any of that money?

3. Secondary-Involvement. A secondary-involvement relevant question tests for
secondary involvement such as seeing or hearing or focuses on physical acts that support the primary offense.

Did you participate in the theft of any of that money?

Comparison Question. Physiological responses of comparison questions are
compared to physiological responses of relevant questions. The comparison question is designed to produce a greater physiological response for the non-deceptive person. The probable lie and directed lie questions are the two types of comparison questions used within the Federal Government.
1. Probable-Lie Comparison Question. This question is designed to be a probable lie
for the examinee. The PLC question should be similar in nature but unrelated by time, place or category to the specific issue. However, in screening examinations the PLC can be related to the issue(s) as long as the screening comparison question establishes a dichotomy between the relevant and comparison issues. A comparison question should be broad in scope and time so that it captures as many of the examinee's past life experiences as possible. The physiological responses to the PLC are compared to the responses of the designated relevant questions. The exclusionary and screening comparison questions are the two types of PLC questions used within the federal government.

Theft issue: Before 1997, did you ever steal anything?

2. Exclusionary Comparison Question (ECQ). A probable-lie question
should be similar in nature but unrelated to the issue being tested. The question should be
separated from the relevant issue by time, place or category. The comparison question should use the same action verb or similar in nature action verb as that of the relevant issue. A comparison question should be broad in scope and time so that it captures as many of the examinee's past life experiences as possible.

Before this year, did you ever steal anything from someone who trusted you?

Directed-Lie Comparison. The DLC question is a specialized comparison
question. A properly constructed DLC question involves a minor transgression which should have some personal significance to the examinee. Upon acknowledging having committed such a transgression, the examinee is directed to lie when asked that question on the test. The question is separated from the relevant issue by category.

Did you ever commit a minor traffic violation?

Sacrifice Relevant Question. When used, this is the first question that refers to the
relevant issue, and it prepares the examinee for the introduction of the relevant questions.
Sacrifice relevant questions are not scored during the test data analysis phase of a PDD
examination.

Regarding the theft of that car, do you intend to answer each question truthfully?

Symptomatic Question. This question is designed to test for an outside issue that
could be more significant for an examinee than the relevant and comparison issues. Symptomatic question responses are evaluated, though not numerically scored, during the test data analysis phase of a PDD examination.

Is there something else you are afraid I will ask you a question about?

Stimulus Questions: designed to measure capacity for response. These can be relevant or irrelevant:

Does 10+ 9= 19?
Were you on that bridge that night?

What do the question formats mean?
The yes/no format means the linguistic construction is always in the hand of the examiner, not the examinee.
The built in shifts from relevant to irrelevant to comparison and control questions indicate an acknowledgment of the difficulty of maintaining accuracy and control in the testing environment.

Problems with the Polygraph:
For instance, using the Directed-Lie Comparison question as an example of how the subject lies poses several real problems since Polygraph measures physiological response and not neurological response. The form of a directed lie question dictates that the subject is instructed to lie. The point of polygraph is to discern a lie based on a spike in stress levels resulting from the concealment of a lie. The Comparison question removes the element of concealment and therefore removes exactly what the examiner wishes to observe: the effects of concealment.
The problems with Polygraph tests are well known to most people today, they measure stress without having a way of differentiating between the stress caused by crafting a lie and the stress caused by being subjected to a polygraph.
Langleben: "Its specificity is limited because it relies on the correlates of peripheral nervous system activity, while deception in a cognition event with top-down control by the central nervous system"
This is the shift his research is trying to make: from physiology to cognition.

The Next Generation of Lie Detection

The Experiment
Subjects: 23 right-handed male undergraduate students (mean age: 19.36)
Task: A modification of the Guilty Knowledge Task (GKT)

Instruction Protocol:
Participants were given an envelope with two playing cards, a 5 of clubs and a 7 of spades, along with $20.
The investigator instructed the participants to deny possession of one of the cards and acknowledge possession of the other during the imaging phase.
Participants were told they could keep the money only if they successfully concealed the identity of the lie card during the scan session.
A third party then led them to the scanner and instructed them to answer each question as truthfully as possible.

A sequence of photographed playing cards was presented
The series of cards included five stimulus classes:
1. Lie (5 of clubs or 7 of spades)
2. Truth (5 of clubs or 7 of spades)
3. Recurrent distracter (2 of hearts)
4. Variant distracter (remaining cards, 2- 10 all suits)
5. Null (back of card)
Cards were presented for 2 seconds followed by a variable (0 -16 s) during which the null card was shown.
24 Lie, Truth and recurrent distracter cards and 168 variant distracter cards were shown.
Participants were instructed to press a left button (yes) to confirm that a card was in their possession or the right button (no) to deny it.
In total, 432 stimuli were presented with a session length of 14.4 minutes.

The experiment still operates with yes/no responses, like the polygraph.

Results:

No difference between those who reported using a strategy and those who reported using no strategy.
"The key point is that you need to exercise a system that is in charge of regulating and controlling your behavior when you lie more than when you just say the truth," Langleben said. "Three areas of the brain generally become more active during deception: the anterior cingulated cortex, the dorsal lateral prefrontal cortex and the parietal cortex."

"Complications arise when we examine Langleben group’s attempts at replication when using this same paradigm. In their 2005 papers (Davatzikos et al., 2005; Langleben et al., 2005), where the same data appear to be reported twice (analysed in two different ways), we ﬁnd that:

1. The initial ACC and inferior parietal lobe ﬁndings are not replicated and the frontal activations described are of insufﬁcient statistical signiﬁcance to be reported by most neuroimaging groups (Z values of less than 3);

2.The parietal lobes (bilaterally) now exhibit greater activation during truthful responding than deceptive responding (c.f. Langleben et al., 2002); and

3.The behavioural and functional anatomical ﬁndings are reported differently across the 2005 papers: while truthful RTs appear only qualitatively longer than lie responses in Langleben et al. (2005), they are reported as signiﬁcantly longer in Davazitkos et al. (2005); while very many regions exhibit greater activation during truthful responding in Langleben et al. (2005), a different subset of foci are maximally informative in Davazitkos et al. (2005; admittedly, following application of a different, and novel, analytic method)."

Conclusion

Admits that brain activity previously associated with deception was driven by the task design
Lie and Truth operate with a similar frontoparietal network, but lie still appears to be a more working-memory associated task

Work Cited

Langleben, et. al. Telling Truth From Lie in Individual Subjects With Fast Event-Related fMRI. University of Pennsylvania, 2005.

Federal Psycho-physiological Detection Of Deception Examiner Handbook. COUNTERINTELLIGENCE FIELD ACTIVITY TECHNICAL MANUAL October 2,2006

Temple-Raston. Neuroscientist Uses Brain Scan to See Lies Form. http://www.npr.org/templates/story/story.php?storyId=15744871. NPR, 2009.

Spence, Sean. Playing Devil's Advocate: The Case against fMRI Lie Detection. Legal and Criminal Psychology (2008) 13, 11-25. The British Psychological Society, 2008.

2009-04-25T10:24:00.000-07:00

Neuroscientist Uses Brain Scan to See Lies Form

Here's the link to my article from Tuesday.

Chelsey Article

2009-04-24T10:17:00.000-07:00

here is the link ot my article...

http://discovermagazine.com/2008/jun/16-could-an-acid-trip-cure-your-ocd

Religious Relaxation

2009-04-13T19:26:00.000-07:00

When God Makes a Difference

   The study conducted by McGregor, Nash, and Hirsh was based around the idea that religious conviction provided a level of certainty and relief from error, which allows those who are strong believers to ignore the inconsistencies that cause people anxiety. Their hypothesis stated that there was a neurophysiological reason for this decrease in anxious feelings, lying in the reduction of activity in the Anterior Cingulate Cortex.

What’s up the ACC?

   The Anterior Cingulate Cortex or ACC is a part of the forebrain located at the frontal part of the cingulated cortex, which lies above the corpus callosum. The ACC is a part of a variety of autonomic functions including blood pressure and heart rate as well as some processes involved in language production and acquisition as we’ve read about in the most recent T. Deacon chapters. However in this study the focus lay on the role of the ACC in more rational cognitive processes such as reward and anticipation and their role in the generation of anxious feelings. Much of the ACCs involvement in error processing lies in its activity in comparing what the intended outcome of a situation is and the actual out come, the ACC responds to an error by aiding in the production of anxious feelings, which allow the subject to become both consciously and physically aware of the error.
   The ACC is connected to the prefrontal cortex, parietal cortex, and motor system. It is thus connected to the general system for regulating and modifying behavior. This regulation occurs in reaction to various anxiety producing events such as “the omission of error, the detection of conflict, or the experience of uncertainty.” They believe this to be true because those who are deeply involved in religion have provided for themselves a set of predictive guidelines for the world and occurrences therein. Religions provide meaning systems and moral parameters that the practitioner may operate within they are essentially guides for action and the perception of the actions of others. Anxiety is often caused by a dissonance between the expected action or situation and what actually occurs, those who seriously practice religion however are given rules that “constrain thought and perception away from discrepant or erroneous predictions”, they are able to ignore that which does not fit the teachings of their religion. The conscious reinterpretation of out of the religious box events into preexisting convictions acts as a sort of natural anti-anxiety medication, deadening the ACCs alarm bell for errors.

Study #1

The first study used twenty-eight subjects who came from Christian, Muslim, Hindu, Buddhist, and other religious backgrounds (including non-religious). The researchers had them complete scaled that measured their personality, need for cognitive closure, behavioral inhibition and activation, as well as on their religious zeal. The religious zeal scale, on which they focused, had items that ranged from “I aspire to live and act according to my religious beliefs” to “I would support a war that defended my religious beliefs”. The participants were given a Stroop test, which consisted of a series of color words, each presented in a color that either matched or mismatched the meaning of the word. They were asked to respond to each word by pressing a button that either matched the color of the word or the color the word represented.

To determine the ACC activity they measured event-related potential “which reflects the summation of the postsynaptic potentials of a large ensemble of synchronously active neurons” called the errorealted negativity or ERN. “The ERN is a sharp negative voltage deflection that typically peaks within 50 to 100 ms postresponse and reflects the preconscious monitoring of error, conflict, and uncertainty localized to the ACC “

The results showed that those who were more religiously zealous had less ERN activity, when an error was made the ACC did not react so strongly that they had a feeling of anxiety or any related emotion in making a mistake. They also found that the more zealous a participant was the less errors they made, they were more deliberate and careful in their answers. However the more zealous participants also answered questions faster suggesting a higher level of automatic thoughts, which allow them to answers quickly with more certainty.

Study #2

The second study consisted of twenty-two participants whose religious preferences were not recorded. They were asked to complete a scale on their belief in God as well as an IQ test and the Big Five inventory, which measures five broad categories of personality traits. They also completed a similar Stroop test.

The results of the second study revealed, just as in the first, that a stronger belief in God led to les ERN activity as well as less incorrect answers. Having belief in God is most certainly a less intense form of religious zeal, however this did not diminish the fact that the participants had less anxiety related activity in their ACC.

These results suggest that religious conviction provides a framework for understanding and behavioral activity in the world, thus acting as a buffer against the anxiety provoking situations as well as “minimizing the experience of error”.

Though these studies are based around religious constructs there is a strong possibility that conviction to any ideology could provide similar results.

Carter CS, Braver TS, Barch DM, Botvinick MM, Noll D, Cohen JD. Anterior cingulate cortex, error detection, and the online monitoring of performance. Science 1998; 280: 747–9.

MacDonald, Angus W., et al. "Dissociating the Role of the Dorsolateral Prefrontal and Anterior Cingulate Cortex in Cognitive Control." Science 288.5472 (2000): 1835-8.

Amygdala Medial Prefrontal Cortex Disconnect

2009-04-13T15:10:00.000-07:00

A great amount of research has been conducted exploring how sleep deprivation weakens systems such as the immune system, weight control, cognitive processing (memory and learning) but there has been little inquiry into how sleep loss effects our emotional brain. Sleep deprivation has been commonly associated with several psychiatric disorders. It is thought that psychiatric and mood disorders, such as bi polar disorder, cause sleep loss. However, Mathew Walker and colleagues new study show that this isn’t necessarily the case as sleep deprivation, as the results from their study indicate, can itself be the cause of psychological instability.

The Study:
The study involved 26 healthy participants ages 18-30. The 26 subjects were divided in two groups: 12 were assigned to a sleep control group and the other 14 to a sleep deprivation group. All subjects had to refrain from ingesting caffeinated and alcoholic beverages for a total of 72 hours and followed a normal sleep/wake pattern for one week prior to the study (7 to 9 hours of sleep per night, waking hours: 6am -9pm). Their sleep/wake pattern was monitored by an actigraphy, a wristwatch movement sensor.

Pre-Study:
The sleep control group subjects had a normal night of sleep the night before the scanning. The sleep deprivation group remained awake for the entire night and the entire day before the scanning at 5pm (total of 35 hours of sleep deprivation).

Study/ fMRI Scanning:
The subjects were shown 100 images ranging from neutral to gruesome (i.e. basket on table to images of burn victims). Each image was shown for 10 seconds and the subjects were asked to quickly rate their emotional response through a button system, this was also to insure that all subjects remained awake and alert during the experiment. The subjects were in fMRI scanners during this whole process. Mathews and his colleagues were particularly looking for reactions in the amygdala, and curious to see if there were any significant differences between the sleep control group and the sleep deprivation group.

Results:
Both groups had similar emotional responses to the neutral images, but as the images became more and more aversive the fMRI scans showed that there were indeed great differences in how the brains were firing in the sleep-deprived subjects. In both groups the amygdala, as hypothesized, showed greater activity in response to the intense images, yet the sleep deprived subjects amygdala’s were 60% more active than the sleep control group subjects. Not only were the sleep deprived subjects amygdalas showing a stronger activation but also the volume of the amygdala that was activated (greater amount of neurons being activated) was three times that of the sleep control subjects.

It also became evident when observing the fMRI scans that there was a difference in the brain wiring of the control subjects and the sleep control subjects. The control subjects amygdalas maintained normal communication with the medial-prefrontal cortex (MPFC), however; the sleep deprivation participants amygdalas appeared to have lost connectivity with the MPFC and were instead communicating with regions of the autonomic nervous system.

Why is this loss of connectivity with the MPFC significant?

The MPFC communicates with the amygdala as it sends connections to the amygdalas central nucleus and brain stem outputs of the central nucleus. The MPFC serves as an “inhibitory, top-down control of amygdala function, resulting in contextually appropriate emotional responses.”

Maria Morgan, working in Joseph LeDoux’s lab, researched damaged MPFC and found that some lesions of MPFC resulted in exaggerated fear reactions. When the amygdala is reacting to fear the MPFC remains inactive and vice versa. When the MPFC is damaged increased anxiety occurs as the amygdala is left “unchecked” by the MPFC. This often leads to a difficulty with decision making in emotional situations. This research supports Mathews and colleagues’ findings. However, in their case study a lack of connectivity between the MPFC and amygdala wasn’t caused by lesions in the MPFC but rather by a lack of sleep.

The heightened emotional state occurs when threatening or in this case disturbing stimuli goes unchecked by the MPFC, and this greater activation of the amygdala communicates with the autonomic nervous system that in turn can lead to fight or flight responses.

Stimuli that activate the fight or flight response trigger the brains periventricular system PVS, commonly known as the brains punishment circuit. The PVS is composed of the hypothalamus, the thalamus, and the gray substance around the Sylvius. Acetylcholine activates emission of a hormone known as adrenal cortico-trophic ACTH which activate the adrenal glands to release adrenalin that prepares the body for fight or flight response.

This case study highlights the great importance of sleep. While more research must be done on the connection of sleep deprivation and mood disorders it is clear that sleep loss affects those without symptoms of psychiatric disorders as well. Most of us have experienced the altered state after pulling an all nighter. Now there is evidence that our brains are literally rewiring to create a heightened emotional state. As more research is conducted sleep might be taken more seriously in terms of psychological instabilities. Perhaps certain careers that often keep employees awake for hours on end who’s decision making is crucial will be reconsidered. For example, medical workers.

Sources:

LeDoux, Joseph. Synaptic Self: How Our Brains Become Who We Are. New York: Penguin Books, 2002.

Swaminathan Nikhil. “Can a Lack of Sleep Cause Psychiatric Disorders? Study shows that sleep deprivation leads to a rewiring of the brain’s emotional circuitry” Scientific American. October 23 2007. Get link

Walker, Mathew P. et al. “The human emotional brain without sleep- a prefrontal amygdala disconnect.” Current Biology. Vol 17 No 20.

Walker, Mathews P. et al “ Supplemental Data: The human emotional brain without sleep- a prefrontal-amygdala disconnect” Current Biology. Vol 17 No 20.

“The Amygdala and its Allies.” The Brain from Top to Bottom
http://thebrain.mcgill.ca/flash/i/i_04/i_04_cr/i_04_cr_peu/i_04_cr_peu_1a.jpg

article for april 14th

2009-04-10T14:02:00.000-07:00

http://www.sciencedaily.com/releases/2009/03/090304160400.htm

Article for 4/14

2009-04-09T16:18:00.000-07:00

Here's my article for April 4th

Autism and Music

2009-03-31T08:40:00.000-07:00

Autism Spectrum disorders affect about 6 in every 1,000 people with varying severities. The prevalence has been drastically increasing since the 1980’s, but most people believe that is not due to an actual increase in the disorder but simply a change in diagnostic criteria.
Autism starts affecting children before the age of three. It is characterized by difficulty with social interactions, repetitive behaviors, and difficulty in acquiring and using language. About 0.5% to 10% of autistic individuals are called autistic savants. They are extremely gifted in one skill set or talent. Though scientists are not in agreement with the causes of autism, there are many theories that dominate the general discourse. It is commonly assumed to be a combination of environmental and genetics with differing emphasis between the two. The research that is compelling for the genetics autism paradigm involves studies of identical twins which proved that there was a 60% chance that the twin of an autistic child would develop autism. These results are staggering considering that .6% of the population has autism and fraternal twins showed no significant increase in autism prevalence.
Further, many researchers have found physical irregularities in several parts of the brain including the levels of serotonin in the brain. Specifically, research centers called “Centers of Excellence in Autism Research” have shown that connections in the brain are often impaired in autistic children. “Research is now being conducted all over the world to determine specific genes that increase the likelihood of someone developing autism. A group known as the International Molecular Genetic Study of Autism Consortium, which includes clinicians and researchers from the USA, UK, France, the Netherlands, Denmark, Italy, and Greece, has pinpointed four chromosomes which they believe play critical roles in autism. The chromosomes they identified are numbers 2, 7, 16 and 17. The evidence for involvement of chromosomes 2 and 7 is particularly strong as these had also been previously identified by other independent researchers (2,3,4,5). Chromosome 7 is known to be associated with many language disorders and chromosome 2 plays an important role in early brain development. These findings are further demonstrated by research showing dyslexia patients also have abnormalities on these chromosomes. This is not surprising as dyslexia also produces deficits in learning ability and information processing in the brain”
The problem with autism is something that we take for granted. Most of us learn how to make sense of our environment through an unconscious ability to combine our sensory information. What we hear, see, feel and know all merge to create spatial maps that allow us to understand our relative place in space. In childhood, we learn how to put our senses together to respond more efficiently to impediments presented to us in our environment. Children with autism have trouble learning to do this. They have greater difficulty creating a synthesis of all the sensory information and therefore have more difficulty responding to the environmental impediments. Sensory integration therapy is a type of occupational therapy that places children in a room specifically designed to stimulate and challenge all of the senses. This therapy is based on the assumption that the child is either overstimualted or understimulated by the environment. Specifically music therapy seeks to stimulate the auditory processing in autistic children so that the overall sensory integration will be more efficient. Music therapy seeks to regulate a common trend in autism; acute lack of total sensory integration. This is reflected and materialized in many ways in the brain.

Auditory Processing of Music
The majority of symptoms in children and adults include attention deficits, learning disabilities, autism, obsessive-compulsive disorder, depression, anxiety, chronic pain and many more are all directly a result of an imbalance of electrical activity in the brain. There are many environmental factors that can produce an imbalance of electrical activity and function of the two sides of the brain documented as either an increase of activity on one side or a decreased activity on the other.
Adverse activity is the right hemisphere which autism is expected to be specifically stimulated by low frequency tones, negative or downbeat music. Specifically, autism is a common sensory processing disorder (SPD). In children with autism, sensory integration is very difficult to accomplish. Music therapy can work as a way to increase the integration of the main sensory areas. The sensory system is broken up into three main areas: the tactile, vestibular, and the proprioceptive sense. The tactile system is your sense of touch. The vestibular system is responsible for movement and the body’s position in space. The proprioceptive system deals with muscles and joints. There are other sensory systems but they are not as commonly associated with sensory dysfunction.
The vestibulocochlear system informs us of sound, movement and orientation of space. The cochlear portion of the system turns sound or vibration into electrochemical messages that are relayed throughout the central nervous system and is critical to auditory processing. The vestibular portion serves to provide stabilization, influences attention and arousal, posture, movement, thus being critical to sensorimotor integration. It is the integration of our senses that allows us to understand what we are experiencing in our world.
Specifically, the vestibular system contributes to our balance and our sense of spatial orientation that provides input about movement and equilibrioception. (equilibrioception is what experiencial information from the vestibular system is called.) It is anatomically joined with cochlear system, and the systems lie closely together throughout the nervous system and together elaborate the general labyrinth of the inner ear.

Further, there is a profound connection between vestibular functioning and language processing. This allows for many close neuronal associations with auditory processing and language. The vestibular system sends signals primarily to the neural structures that control our eye movements, and to the muscles that keep us upright.
Decreased vestibular processing can impact on the area of speech and language development, particularly auditory processing. It is associated with autistic disorder, which are generally categorized by decreased electrical neurotransmitting activity. Research has found that therapy to improve the function of the vestibular system can also result in improved language development.

Musical Processing and Emotional Understanding
Vestibular complications are not the only ways that music can affect autism. A benefit to music therapy for autistic children aids them in verbal communication and social interaction deficits. A proposed study by Molnar Szakacs and Overy wants to compare musical processing on a neurological basis to communication, language and action. This is determined by the mirror neuron system, which allows us to abstract musical sounds similar to the ways in which humans form language when speaking and interacting. “The mirror neuron system has been proposed as a mechanism allowing an individual to understand the meaning and intention of a communicative signal by evoking a representation of that signal in the perceivers own brain “(p.235.) Spatial maps created in the brain, specifically the parietal lobe, are influenced by these mirror neurons and contribute to an overall understanding of actions and intentions. Essentially, mirror neurons enable humans to understand emotions through facial and body expressions.
Music is closely connected with motor activity. Producing music involves developed spatial maps and a physical understanding of vibrations and sounds. The mirror neuron system that allows someone to understand musical experiences is the same set of neurons that is present in motor functioning and mapping. There have been recent neuro-imaging studies that show that people with musical expertise have a change in their fronto-parietal mirror neuron system. Music is also inherently similar to language. Music is pitches composed into symphonies the way that language is words composed into novels.
The proposed study by Molnar Szakacs emphasizes the important connection between an understanding of language with an understanding of music. This is further emphasized by research conducted on other language disorders like dyslexia. The main point that Molnar Szakacs intends to look at is if language and music are so similar and if they are dictated by similar mirror neural patterns, then why can’t autistic savants with high pitch sensitivity understand facial emotions and social communications?
Mirror neurons are cells that enable normally developing people to decipher meaning and intention in actions as well as replicate those actions. Autistic children are typically noted to have a decreased or altered mirror neural system. This affects the ways in which the limbic system, which is responsible for emotions, interacts with those mirror neurons. This comes back to the point that these same mirror neurons are involved in the understanding of music.

Music Based Therapies

So it makes sense that a program that would stimulate and help to integrate the cochlear and vestibular systems might be very helpful for the autistic child’s emotional understanding. This does not present a cure for autism, but The Listening Program (TLP) can be an effective intervention for children on the autistic spectrum.
TLP is a music-based sound stimulation program that currently consists of 8 one hour audio CD’s that contain specially processed classical music and nature sounds plus a 112 page guidebook. Listening sessions are typically fifteen minutes in length, done once or twice a day, five days a week, using high quality stereo headphones.

1- Increases engagement- The individuals experience an improvement in their self-image and an improved sense of their body in space. This enables them to feel more comfortable interacting with their surroundings. They show an increase in the toleration and need for physical contact. There is also an increase in attentiveness and initiation of eye contact.
2- Emerging Skills- When used in conjunction with other forms of therapy, it allows for better integration of the motor and sensory systems which in turn leads to a faster rate of skill acquisition.
3- Auditory Processing- It improves the accuracy and speed at which individuals process sound. This leads to better overall communication skills.
4- Reduced Sound Sensitivity- Many autistic individuals experience hypersensitivity to sounds because their nervous system is unable to regulate the sensory input. This program helps the nervous system be able to better process sensor info, which reduces sound sensitivity.

2009-03-30T16:39:00.000-07:00

Obesity: Reviving the Promise of Leptin

The History of Leptin

Discovered by Douglas Coleman (The Jackson Laboratory, Bar Harbor, Maine)

Parabiosis of normal mice with either diabetic or overweight mice.

Found that there was a "satiety factor" circulating in the blood. Hypothesized that db mice lacked the receptor to the factor, while ob mice did not produce it.

It could not be extracted from the blood because it was present in tiny amounts. However, the gene responsible for it was eventually isolated and the "satiety factor", leptin, was produced in a lab. The leptin gene is spliced into bacteria and the bacteria sets to work producing the protein.

By the mid 1990s it was greeted as a possible miracle cure for the rising obesity epidemic. 1995 New York Times headline read: "Researchers find hormone causes a loss of weight". Leptin is discussed as a "magic bullet", which would hopefully "change the image of obesity, helping people to see it not as a punishment for gluttony but rather as a metabolic disorder, treatable with a remedial hormone just as diabetes is treated with insulin."

By the end of 90s none of the new research had panned out. All experiments that had been done on obese humans had found that leptin rarely caused weight loss, and if it did it was only temporary. New York Times headline from 1999 read: "Hormone t hat slimmed fat mice disappoints as panacea in people". Researchers determined that obese people were somehow resistant to leptin, so it was not effective in their brain.

Since then most research has focused on understanding the metabolic pathways of leptin, and little thought has been given as to how it might be used as a treatment for obesity.

How is Appetite Controlled?

Hypothalamus is the main organ involved in regulation of appetite; specifically the arcuate nucleus (situated at the base).

The neurons involved primarily employ serotonin as a neurotransmitter, although neuropeptide Y and Agouti-Related peptide are also involved.

The hypothalamus uses Ghrelin, Leptin, Insulin and PYY as markers to influence how hungry we feel.

Ghrelin is excreted by the stomach may also be produced in the brain. Causes feelings of hunger and is associated with regular meal times. Ghrelin levels rise immediately before a meal and fall sharply after eating.

Ghrelin Factoids: Those suffering from anorexia nervosa have higher blood levels of ghrelin. - Individuals who have undergone gastric bypass surgery produce less ghrelin. - Ghrelin acts not only on neurons in the arcuate nucleus but also activates reward circuitry in the brain associated with dopamine.

Leptin is mainly produced by white adipose tissue. Leptin blood level is proportional to body fat. The more body fat on the body the more leptin that is produced.

Differences in brain activity during eating in people with leptin deficiency and those with normal leptin levels.

When leptin is given to genetically obese mice they lose 30% of their body weight in 2 weeks. When leptin is given to lean mice they lost all their body fat in 4 days.

Human trials with leptin were unsuccessful. Except at the highest doses (several tablespoons a day) there were no significant changes in weight.

Why was it so unsuccesful? Obese humans develop a resistancy to leptin in their brain.

Explaining and Reversing Leptin Resistance

Umut Ozcan - Harvard - Endoplasmic Reticulum Stress Plays a Central Role in Development of Leptin Resistance

General Hypothesis: The hypothalamus has become resistant to leptin through a process called Endoplasmic Reticulum Stress (ER Stress) which ultimately results in reduced ER function. This causes reduced function of Leptin Receptor signaling. To resensitize the brain to leptin it is necessary to improve function in the ER. Chemical chaperones have been shown to do this.

The Endoplasmic Reticulum is an organelle responsible for protein folding and transportation of proteins to the cell membrane.

If the normal processes of the ER are disturbed misfolded proteins accumulate in the cell. This activates cellular stress mechanism called the Unfolded Protein Response (UPR) is activated.

UPR halts protein translation and causes an increase in the production of molecular chaperones involved in protein folding. If this mechanism is unsuccessful, UPR leads to apoptosis.

How ER stress is induced and how this leads to UPR is not well understood. The main theory suggests that increased levels of circulating cytokines, fatty acids, excess nutrition and activation of the rapamycin pathway (involved in cellular homeostasis) contribute.

What they demonstrated in the paper:

Leptin Acts on a Subset of Hypothalamic neurons
ER Stress Inhibits Leptin Receptor Signaling
ER Stress Creates Leptin Resistance in the Brain of Lean Mice
Improvement of ER Function Enhances Leptin Signaling
ER Capacity of the Brain Links Obesity to Leptin Resistance
Chemical Chaperones are Leptin Sensitizers.

2. ER Stress Inhibits Leptin Receptor Signaling

Cells that presented the Leptin Receptor (LepRB) were exposed to tunicamycin (a chemical that induces ER stress) and then treated with leptin for 45 minutes.

There was no evidence of leptin-stimulated tyrosine phosphorylation of LepRB or Stat3 phosphorylation (both cellular events that occur as a result of leptin binding to LepRB).

This indicates that UPR inhibits LepRB signaling at all steps.

Since LepRB is folded in the ER they next investigated ER stress blocks LepRB translocation from the ER to the cell membrane as a possible explanation of the block in leptin signaling.

They induced ER stress in cells using tunicamycin and then used immunflorescence staining to analyze LepRB levels in the cell membrane. They found that ER stress does not decrease LepRB translocation to the membrane nor does it cause a misfolding of LepRB.

3. ER Stress Creates Leptin Resistance in the Brain of Lean Mice

First - Showed that injecting tunicamycin into the hypothalamus of lean mice caused ER Stress.

Second - Showed that ER stress in the brain's of lean mice completely blocked activation of Stat3.

Third - Noted that the food uptake of lean mice with induced ER stress in the hypothalamuc increased.

5. ER Capacity of the Brain Links Obesity to Leptin Resistance

Bred XNKO mice that produced less of the regulators involved in protein folding in the ER therefore making them more susceptible to ER stress (deletion of the XPB1 gene).

On a normal diet they had a slightly lower body weight. Blood glucose and leptin levels were normal. Glucose homeostasis was maintained within a normal range.

On a high fat diet the XNKO mice gained weight more quickly. A sharp increase in leptin level was maintained through out the experiment. They consumed more food, had a higher total fat amount and a significantly lower lean mass.

These results support the hypothesis that ER capacity of the brain is involved in regulating body weight, leptin sensitivity and metabolic homeostasis.

6. Chemical Chaperones are Leptin Sensitizers

Chemical chaperones are compounds that have been found to increase ER function and decrease the accumulation of misfolded proteins in the ER, thereby reducing the likelihood that ER stress will occur.

2 FDA approved chemical chaperones for humans are 4-phenyl butyrate (PBA) and tauroursodeoxycholic acid (TUDCA). Past studies have shown that these chemicals can relieve ER stress in the liver and adipose tissues, as well as enhancing insulin sensitivity in mouse models.

Attempted to reverse ER stress in the hypothalamus of mice who had been on a high fat diet. Normal mice were kept on a high-fat diet for 25 weeks and then treated with PBA for 10 days, followed by daily leptin administration.

Control mice rapidly lost weight and then rapidly regained it. Mice treated with PBA rapidly loss weight, they also consumed less food.

Similar results were obtained with TUDCA.

Both PBA and TUDCA also had some success in increasing leptin sensitivity in genetically obese mice (ob/ob mice).

What This Means

After years of searching for leptin-sensitizing agents, chemical chaperones have been identified as potential novel treatment options for obesity.

Music evokes emotion in children with autism

2009-03-29T22:50:00.000-07:00

Here's my article.

Music and Autism

Musical Behavior in a Neurogenetic Developmental Disorder

2009-03-29T15:35:00.000-07:00

Evidence from Williams Syndrome

Daniel J. Levitin

Daniel J. Levitin's paper reviews a series of studies performed to assess the musical abilities and behaviors of individuals with Williams Syndrome- a neurogenetic developmental disorder.

What is Williams Syndrome (WS)?

Williams Syndrome is created by a small genetic accident which occurs during meiosis, when a segment of DNA containing 25 genes is lost. The result of which affects abstract thought, so that many WS have a bad concept of spacial, quantitative, reasoning, attention, eye-hand coorination, and reading abilities. WS people tend to be very talkative, and will talk with everyone; they completely lack a sense of social fear. Functional brain scans have shown that the amygdala in WS people shows no reaction when they see angry or worried faces.

Here is an image taken from the National Institutes of Health website depicting the difference in amydala activity scanned in reaction to threatening scenes and faces in WS participants and controls (http://www.nih.gov/news/pr/jul2005/nimh-10.htm)

Abnormal regulation of the amygdala in participants with Williams Syndrome (right) compared to controls (left). The amygdala activates more for threatening scenes (bottom), but less for threatening faces (top).

What is the connection between WS and music?
Not only do WS people show extreme friendliness and near-normal speaking skills, they also tend to be more engaged in musical activities and musicality than others. Levitin reports in this paper a possible neuroanatomical correlate of this engagement, with increased activation in the right amydala to music and to noise.

Based on Levitin and his team's observations, claims of musicality involve many aspects of music including frequent music listening, music performance (for example: a WS person can be able to play the clarinet despite not knowing how to tie their shows) , a deep emotional engagement with msuic, or an above-average musical memory and sound sensitivities (hyperacusis) involving unusual sensitivity to sound, categorization or labelling of sounds that others can't, or anxiety and fear of sounds that non-WS people do not find aversive.

Levitin says that WS can help us better understand the links between genes, brain, and musical behaviors and that WS hypersociability and lack of social inhibitions might be related to their musicality.

The Studies

1st Step:
Characterizing the musical phenotype in WS
The Questionnaire.
Levitin administered a questionnaire to the caregivers of 130 WS participants, 130 Down syndrome participants, 130 autistic participants, and to 130 normal controls. The questionnaire gathered information about physical variables, interest in music, emotional responses to music, musical training, the amount of time engaged in musical activities, and the age of onset of musical activities.

Individuals with WS showed a significantly younger age of onset of musical interest, spent more time per week listenign and playing, and were reported to experience higher levels of emotion when listening to music.

A prinical components analysis revealed seven underlying orthogonal factors that contributed to the profile obtained from the questionnaire. This can be divided up into 7 factors including content related to musical complexity, reproduction, sensitivity, musical theory and achievement, listening habits, positivity, and emotions.

Study of Neural Correlates of Auditory Perception in WS using fMRI

Levitin hypothesized that he would find differences in brain activation bewteen people with WS and controls, and that WS people would show a wider and more diffuse pattern of activation to music and noise stimuli than controls, and that they would show a greater amygdaloidal activation, indexing their heightened emotional reations to music and noise.

Study was conducted usuing a desensitization program that involved a professionally proudced video introdcution to the fMRI scanning procedure, usuing a child's-eye-view of the facility and a child's narration. This was followed to a visit fo an fMRI simulator in which the participants could become acclimated to the noises and enclosed space. 5 WS participants were recruited for an fMRI study of differential processing of music and noise, and five age- and sex-matched controls.
Participants listened to to excerpts from familiar and unfamiliar classical music, as well as the types of noisy sounds that WS people are often sensitive to, such as fans, motors, and leaf blowers.

Results:

Comparing music to noise, WS individuals showed a significantly lower voxel intensity bilaterally in the superior temporal cortex, middle temporal gyri, and superior temporal sulcus. In a comparison of responses to music-minus-rest vs. noise-minus-rest, control participants showed significantly higher temporal lobe activations to the music than the noise, while the WS participants showed virtually indistinguishable activation levels.

He also observed marked differences between WS patients and controls in the right amydala, with WS patients exhibiting far greater activation intensity in the music-minus-noise contrast. This points to a possible neural basis for the unusal acoustical and musical sensitivities observed in affected individuals. Overall, WS participants showed more variable and diffuse activations throughout the brain, and the showed increased activation in the amygdala and cerebellum.

The test of musical skills:

Rhythmic Production Ability

To test rhthym, Levitin and his team presented 8 WS individuals and 8 mentally age-matched controls with a set of clapped rhythums in increasing complexity. The participant had to clap back the rhythm as accurately as possible. Independent coders, blind to hypothesis, and group membership, analyized audio tapes of the test sessions and scored each trial as correct or incorrect or incorrect but very musical nonetheless.

The results showed that the WS and control participants obtained an equal number of correct trials about 66%. However, WS indiviuduals were three times more likely when incorrect to supply a musically compatible rhythm. This was interpreted as a marker of rhythmic ability or creative rhythmicity among the WS participants.

Melodic Production Ability

Levitin presented 12 WS individuals, 12 chronologically age-matched NCs, and 12 individuals with DS a set of melodies increasing in complexity, to assess their melodic reproduction ability. WS and NC were statistically better at melodic repetition than the DS, and not significantly different from one another. He then presented all participants with a set of melodic fragments and instructed them to complete the melodies. The WS individuals were not as good at melodic completion as the NCs. Thus, WS individuals are better at rhymic production than melodic production.

Sources:

Levitin, Daniel J. (2005) Musical Behavior in a Neurogenetic Developmental Disorder, Retrieved March 15, 2009 from Daniel J. Levitin's Website: http://www.psych.mcgill.ca/levitin/

Dobbs, David "The Gregarious Brain." The New York Times July 8, 2007. Retrieved on March 15, 2009 from nytimes.com

Obesity: Reviving the Promise of Leptin

2009-03-25T14:22:00.001-07:00

Hi everyone,

Here's the link to my article: Obesity: Reviving the Promise of Leptin

Musical Behavior in a Neurogenetic Developmental Disorder

2009-03-15T11:45:00.000-07:00

Here is the link to the article by Daniel J. Levitin:

http://ego.psych.mcgill.ca/labs/levitin/research/MusicalBehaviorNeuro.pdf

And here is a link to a NYtimes article which explains Williams syndrome:

http://www.nytimes.com/2007/07/08/magazine/08sociability-t.html

Medial Prefrontal Cortex Links Music, Memory, and Emotion

2009-03-02T20:59:00.000-08:00

In a study at UC Davis, Petr Janata mapped the areas of the brain that responded to clips of familiar music, to explore the locations that play a role in the integration of music and autobiographical memories. The area he established as the “hub” that links familiar music, memories, and emotions is the medial prefrontal cortex (MPFC), already understood to be where memories are “supported and retrieved.”

Janata based his hypothesis that the MPFC would be at the center of activity on several previous studies that showed it to be involved in autobiographical memory retrieval. In several of his own earlier studies, Janata had observed that the MPFC is used to track music through tonal space, and that music serves as a powerful retrieval cue for autobiographical memories. Another compelling study showed that the MPFC atrophies more slowly than other brain areas in patients with Alzheimer’s disease, and that memory for familiar music is something that these patients retain longer than many other memories.

There were two hypotheses being tested in this experiment: the first is that activity in the MPFC would show positive correlation to the familiarity, autobiographical salience, and positive affect brought about by the music. The second was that overlapping areas, of those in close proximity to those demonstrating positive correlation, would track the musical excerpts through tonal space. For the sake of time, I will address the first hypothesis.

Method:
Janata’s study involved 13 students at UC Davis. Using songs from the Top 100 charts from when the subjects were between 7 and 19 (to ensure there would be some familiarity with the songs), Janata used fMRI scans to monitor their brains while they listened to 30 second excerpts from 30 different songs.

Following each excerpt, subjects pressed buttons on a keypad to respond to questions about the valence (how pleasant the music was) and arousal while listening to the clip, their familiarity with the song, whether it held any particular autobiographical associations for them, the orientation of their attention to those associations/memories, and the orientation of their attention to the music itself. After the fMRI monitoring, subjects completed a survey about the memories they had experienced while listening to the song excerpts.

Results:
From the 17 songs that the subjects remembered on average, 13 had moderate to strong associations to autobiographical memories. Songs that had the strongest associations also evoked the most emotional, vivid responses. In the fMRI images, these memories corresponded to activity in the upper part of the MPFC.

This shows the results of the ratings the subjects assigned to each song excerpt. Black represents the most negative value for each scale, and white represents the most positive.

Abbreviations: STG, superior temporal gyrus; DLPFC, dorsolateral prefrontal cortex; DMPFC, dorsomedial prefrontal cortex; VLPFC, ventrolateral prefrontal cortex; VMPFC, ventromedial prefrontal cortex; IFG, inferior frontal gyrus; FO, frontal operculum; IPS, intraparietal sulcus; AG, angular gyrus; pSMA, presupplementary motor area; ACC, anterior cingulate cortex; PCC, posterior cingulate cortex; IFS, inferior frontal sulcus; MFG, middle frontal gyrus; Ins, insula; SPL, superior parietal lobule; Cb, cerebellum; PT, planum temporale; vltn, ventral lateral thalamic nucleus; and MTG, middle temporal gyrus.

In these images, you can see brain activity during different phases of the experiment: music playing, question-answer period, and the effects of familiarity, autobiographical salience, and valence. FAV represents “the combined effects of hearing pleasing, familiar, and autobiographically salient songs relative to unfamiliar, emotionally neutral, or displeasing songs that elicited no autobiographical association.” These images show the concentration of activity related to associations in the prefrontal cortex, as well as the left-hemispheric bias (the negative numbers refer to the left hemisphere).

In this second set of images, you can see the individual effects of familiarity, autobiographical salience, and valence, showing the same trends as the first set of images.

Implications:
Janata’s results show that the MPFC is key in associating familiar music with autobiographical memories. Importantly, it links structural characteristics of a retrieval cue with episodic memories (in spontaneous, rather than effortful, retrieval). This builds on existing knowledge of autobiographical memory by demonstrating the “spontaneous activation of an autobiographical memory network in a naturalistic task with low retrieval demands.”

Although Janata’s study itself did not suggest the uses or applications of this discovery, he is quoted in the ScienceDaily article as saying that a long-term goal for this new knowledge was to use music to improve Alzheimer’s patients’ quality of life.

Sources:
Janata, P. (2009). The Neural Architecture of Music-Evoked Autobiographical Memories. Retrieved February 24, 2009, from Cerebral Cortex Website: http://cercor.oxfordjournals.org/cgi/content/full/bhp008v1#ABS

Nervous System. Retreived March 1, 2009, from A Review of the Universe Web site: http://universe-review.ca/R10-16-ANS.htm

University of California - Davis (2009, February 24). Brain Hub That Links Music, Memory And Emotion Discovered. Retrieved February 24, 2009, from Science Daily Web site: http://www.sciencedaily.com/releases/2009/02/090223221230.htm

Imaging Study on Women with Anorexia Nervosa

2009-03-02T08:44:00.000-08:00

"Sense of Taste Different in Women with Anorexia Nervosa"  Imaging Study Finds Brain Changes Associated with the Regulation of Appetite .
September 25, 2007
By Debra Kain

Although anorexia nervosa is categorized as an eating disorder, it is not known whether there are alterations of the portions of the brain that regulate appetite. Now, a new study finds that women with anorexia have distinct differences in the insula – the specific part of the brain that is important for recognizing taste – according to a new study by University of Pittsburgh and University of California, San Diego researchers currently on line in advance of publication in the journal Neuropsychopharmacology. The study also implies that there may be differences in the processing of information related to self-awareness in recovering anorexics compared to those without the illness – findings that may lead to a better understanding of the cause of this serious and sometimes fatal mental disorder. In the study led by Angela Wagner, M.D., University of Pittsburgh School of Medicine, and Walter H. Kaye, M.D., of the University of Pittsburgh and the University of California, San Diego (UCSD) Schools of Medicine, the brain activity of 32 women was measured using functional magnetic resonance imaging (fMRI.) The research team looked at images of the brains of 16 women who had recovered from anorexia nervosa – some of whom had been treated at the Center for Overcoming Problem Eating at Western Psychiatric Institute and Clinic of the University of Pittsburgh Medical Center –and 16 control subjects. They measured their brains’ reactions to pleasant taste (sucrose) and neutral taste (distilled water.)
The results of the fMRI study are the first evidence that individuals with anorexia process taste in a different way than those without the eating disorder. In response to both the sucrose and water, imaging results showed that women who had recovered from anorexia had significantly reduced response in the insula and related brain regions when compared to the control group. These areas of the brain recognize taste and judge how rewarding that taste is to the person. In addition, while the controls showed a strong relationship between how they judged the pleasantness of the taste and the activity of the insula, this relationship was not seen in those who had recovered from anorexia. According to Kaye, it is possible that individuals with anorexia have difficulty recognizing taste, or responding to the pleasure associated with food. Because this region of the brain also contributes to emotional regulation, it may be that food is aversive, rather than rewarding. This could shed light on why individuals with anorexia avoid normally “pleasurable” foods, fail to appropriately respond to hunger and are able to lose so much weight. “We know that the insula and the connected regions are thought to play an important role in interoceptive information, which determines how the individual senses the physiological condition of the entire body,” said Kaye. “Interoception has long been thought to be critical for self-awareness because it provides the link between thinking and mood, and the current body state.” This lack of interoceptive awareness may contribute to other symptoms of anorexia nervosa such as distorted body image, lack of recognition of the symptoms of malnutrition and diminished motivation to change, according to Kaye. Anorexia nervosa is a serious and potentially lethal illness, which may result in death in ten percent of cases. Anorexia commonly begins during adolescence, but strikes throughout the lifespan, and is nine times more common in females than in males. These characteristics support the possibility that biological processes contribute to developing this disorder.

Why does this study hold significance?

Anorexia Nervosa is a disorder of unknown etiology. The stigma that has lastingly attached itself to the disease supports that psychological reasons are responsible for the birth of the disorder. Despite this, it is being questioned whether individuals afflicted with anorexia, have a primary disturbance of pathways that modulate feeding, or if disturbed appetite is secondary to psychological elements of the disease such as anxiety, and an obsession with weight gain. Through this case study, we are able to see that the controlled women acknowledged a pleasant relationship with the ingestion of sucrose and their signal activity supported that as well. Conversely, the recovered anorexics of this study possessed no relationship between the pleasantness of sugar’s taste and any brain region. Both groups showed no anxiety or pleasantness of the taste of water in relation to any brain region. These results support the hypothesis that recovered anorexics have disturbances in their taste processing via the central nervous system. We see that the insula can assert the value of taste stimuli and consequently influence how that stimuli affect’s the state of the human body. If an anorexic cannot distinguish her feelings towards particular foods—if she experiences no neurological reward or taste value—it is easier for her to fall into disordered eating habits, especially if she has psychological instabilities that would only strengthen her resistance to food. Essentially, this study was the first of its kind in showing that there is a disturbance in the insula and other primary taste regions of the brain in anorexics, which in turn can help professionals potentially treat Anorexia Nervosa in a more inclusive way.

http://www.nytimes.com/2007/02/06/health/psychology/06brain.html

The link above has a more specified article on the insula, and an interesting diagram to match, if anyone wants more background information on the insula.

Other Sources:

www.neuropyschopharmacology.org
"The Mind Has a Body of its Own," by Sandra and Matthew Blakeslee.

Oxytocin and Generosity

2009-03-01T10:00:00.000-08:00

The Study:

The study attempted to connect the neuromodulator oxytocin with increased generosity by showing that it increases perspective-taking or empathy.

To isolate oxytocin’s impact on perspective-taking, the researchers used two money transfer tasks, the Ultimatum Game and the Dictator Game

In both tasks, participants were randomly assigned to pairs, but did not have the opportunity to see or converse with their partners. One member of the pair (referred to as Decision Maker 1, in the study, but referred to here as the Giver) was given $10. The other member of the pair (referred to in the study as Decision Maker 2, but referred to here as the Receiver) received no money at the start of the game.

Ultimatum Game: In the Ultimatum Game, the Giver was asked to choose an amount of money to transfer to the Receiver. If the Receiver accepted the transfer, both partners got the agreed-upon amounts of money. If, on the other hand, the Receiver rejected the offer as too stingy, neither partner kept any money. The Giver only had the opportunity to make one offer and could not renegotiate.

Dictator Game: In the Dictator Game, the Receiver had to accept whatever amount of money was given to him by the Giver.

The Ultimatum Game differs from the Dictator Game in that, in order to succeed at the task, the Giver must think about what the Receiver will do. The researchers encouraged this by asking all participants, before they were assigned to particular roles, to think about both the amount they would transfer as a Giver and the minimum amount they would accept as a Receiver. In the Dictator Game, the Giver does not need to explicitly think about the Receiver, but instead “simply decides how much one would like to give up.”

Before completing these tasks, half of the participants were infused intranasally with oxytocin and the other half were given an intranasal placebo to see what effect oxytocin would have on decision-making in the two games.

The Results:

As the researchers predicted, oxytocin increased the magnitude of transfers in the Ultimatum Game, but not in the Dictator Game. Only when participants had to think about another person did oxytocin affect they amount they were willing to give. Participants who had received oxytocin gave 21% more as Givers in the Ultimatum Game than those who had received the placebo.

The average transfers in the Ultimatum Game were $4.86 for the oxytocin group and $4.03 for the control group.

The researchers distinguished between generosity and altruism.

Generosity: Liberality in giving. Offering more to another than he or she expects.
Altruism: Helping another at a cost to oneself.

The Ultimatum Game most nearly tests generosity, since it compares the amounts a person is willing to give to an amount that is expected, while the Dictator Game most nearly tests altruism, since it measures how much of a cost to oneself one is willing to endure, without any particular mark of comparison.

In the Ultimatum Game, significant generosity is shown by participants who have taken oxytocin, meaning that these participants gave more than the average amount that people would be willing to accept as a Receiver. Those who had taken oxytocin were 80% more generous.

From this, the researchers concluded that oxcytocin increases generosity, but not altruism, by increasing participants’ ability to take on the perspective of another person. The researchers hypothesized that when participants in the oxytocin group thought about the Receiver while acting as Giver in the Ultimatum Game, they identified more strongly with the disappointment and negative emotions that the Reciever would feel if the transfer was small, and so they gave larger amounts. The paper states, “OT [oxytocin] appeared to have selectively affected the understanding of how another would experience a negative emotion, and seemed to have motivated a desire to reduce DM2s’ [Receivers’] experienced negativity. This could be called empathy.”

An Alternative Reading of the Data:

Another explanation for the effects of oxytocin in the Ultimatum Game could be that oxytocin decreases risk-taking behavior. Givers who have received oxytocin might give more because they prefer to secure a smaller amount for themselves than to risk having their offer rejected and getting nothing. This explanation is not likely, however, because oxytocin did not have any effect on the minimum offer that participants were willing to accept as Receiver. If oxytocin led to risk-aversion, Receivers would also be willing to accept smaller, secure amounts, rather than sticking to a higher acceptance threshold. Also, another experiment, primarily designed to study the effects of oxytocin on trust levels, showed that oxytocin does not affect risk-taking.

Calling Out Discover:

The end of the Discover article raises the spectre of casinos filling the air with oxytocin to make people gamble more. As I just stated, the actual study suggests no link between oxytocin and risk-taking. The increased payouts in the study occurred only when participants were induced to actively think about the person who would benefit from their giving. This would be helpful to casinos only if people pulling the slot machine considered how the casino owner would feel about receiving their money—an unlikely scenario. The Discover comment is purely sensationalist.

What is Oxytocin Anyhow?

Oxytocin is a neuromodulator which is primarily known for its involvement in female reproduction. It is critical to birth and breastfeeding. Recent research has discovered that it is also very important in regulating social interactions. One study showed that mice with a mutant gene that prevented them developing oxytocin receptors lacked social memory. The connection between oxytocin and sociality is supported by the fact that areas of the brain that deal with emotions and social behavior tend to have more oxytocin receptors. These areas include the amygdala, hypothalamus, and anterior cingulate.

fMRI Evidence:

In a recent study, participants decided whether or not to make donations to social causes while undergoing an fMRI. The study found that, when participants chose to make donations, the mesolimbic-striatal reward system was activated in the same way as when participants were given monetary rewards. This accounts in part for the positive feelings associated with giving. In addition, participants making donations showed activation in the subgenual area (including Brodmann’s area 25) which was not activated while receiving money. This area is important in social attachment and affiliation. It is also involved in the release of oxytocin, suggesting that oxytocin has an effect on making decisions about donations. This reinforces the link between oxytocin and generosity.

(a) Mesolimbic–striatal reward system, including the VTA and the dorsal and ventral sectors of the striatum (STR), activation for both pure monetary reward and noncostly donation (conjunction of pure reward vs. baseline and noncostly donation vs. baseline). (b) Subgenual area (SG) activation for decisions to donate (conjunction of costly and noncostly conditions) as compared with pure monetary reward. The subgenual area comprised the most posterior sector of the medial orbitofrontal cortex and the ventral cingulate cortex (BA 25) and the adjoining septal region structures. (Caption taken from Moll, J., et. al.)

Area 25 was activated during the donation task, and is involved in the release of oxytocin.

Another study examined the effects of oxytocin on the amygdala. Participants were given either oxytocin or a placebo intranasally. Then, while undergoing an fMRI scan, they viewed angry and fearful faces and threatening scenes. For those who had received the placebo, this caused a large amount of activation in the amygdala. Those who had received oxytocin showed significantly less activation in the amygdala, suggesting that oxytocin can interfere with fear responses. The authors of “Oxytocin Increases Generosity in Humans” suggest that interference with the amygdala by oxytocin may make people less anxious about resource scarcity, and therefore more likely to give larger amounts in the Ultimatum Game. Another study has shown that oxytocin increases people’s willingness to trust strangers. This effect could be attributed to decreased activity in the amygdala inhibiting normal fear of betrayal.

Significance:

As the role of oxytocin in regulating social behavior comes to be better understood, it could be involved in new treatments of social disorders. The connection between oxytocin and perspective-taking indicated by this study may be of particular importance to autism researchers.

Sources:

Barone, J (2008) Can the hormone oxytocin drive us to be more generous? Discover. Retreived February 21, 2009, from http://discovermagazine.com/2008/apr/04-a-dose-of-human-kindness-now-in-chemical-form

Ferguson JN, Young LJ, Hearn EF, Matzuk MM, Insel TR, Winslow JT (2000) Social amnesia in mice lacking the oxytocin gene. Nat Genet 25: 284–298.
Kosfeld M, Heinrichs M, Zak PJ, Fischbacher U, Fehr E (2005) Oxytocin increases trust in humans. Nature 435: 673–676.

Moll J, Krueger F, Zahn R, Pardini M, de Oliveira-Souza R, Grafman J (2006) Human fronto–mesolimbic networks guide decisions about charitable donation. Proc Nat Acad Sci 103: 15623–15628.

National Institute of Mental Health (2005) Trust-building hormone short-circuits fear in humans. Retrieved February 21, 2009, from http://www.nih.gov/news/pr/dec2005/nimh-07.htm

Zak PJ, Stanton AA, Ahmadi S (2007) Oxytocin Increases Generosity in Humans. PLoS ONE 2(11): e1128. doi:10.1371/journal.pone.0001128

2009-02-28T06:49:00.000-08:00

Just a test post!

Music, Memory, and Emotion

2009-02-24T10:10:00.001-08:00

Here is my article from ScienceDaily:

Brain Hub That Links Music, Memory And Emotion Discovered

Enjoy!

Oxytocin and Generosity

2009-02-21T12:52:00.000-08:00

For March 3:

http://discovermagazine.com/2008/apr/04-a-dose-of-human-kindness-now-in-chemical-form

Report on Invisible Images, Attention, Awareness, and Possibilities in Subliminal Messaging

2009-02-17T08:44:00.001-08:00

A study conducted at University College of London notes the effect of attention on the brain's neurological responses to invisible images. The study's findings show that visual attention levels affect one's awareness of suppressed, or 'invisible' peripheral images -- attention and awareness affect each other but do not necessarily accompany each other. Some of the most interesting implications for this study are in the field of subliminal advertising -- does it work, and how? Here is the article and study explained.

How does an image become invisible?

Bahrami, et. al. used the same method to render images invisible as did a previous team, Fang and He. This method is called flash suppression. It goes as follows: a low-contrast, simple image (of a tool such as a wrench in this study) is shown to one eye while simultaneously, a high-contrast, dynamic noise image is flashed repeatedly to the other eye. In each eye's visual field, the image locations are the same. Subjects of the study were unable to detect the fainter, simpler image, "confirming their complete lack of awareness" that they'd seen it at all - hence, invisibility.

Invisible, but still affecting your brain:

Fang and He found that despite their lack of awareness of the tool images, subjects were nevertheless affected at the neurological level. Using function Magnetic Resonance Imaging (fMRI), they found that the tool images "activated dorsal visual areas along the intraparietal sulcus at almost normal levels, but did not activate ventral visual areas of the lateral occipital complex." This affirms the 'conventional notion' that conscious visual perception is supported by the ventral visual cortex, while 'subconscious' vision (see image below) is supported by the dorsal visual cortex. Essentially, Fang and He found that a subject could 'see' an object with his brain, with almost a completely normal neurological effect on the dorsal side, while remaining completely unaware that he has done so - ventral side unaffected.

Ventral vs. Dorsal pathways illustrated:

Bahrami, et. al. investigate attention’s effect on awareness:

The study noted in the original ScienceDaily article, conducted at Univerity College of London, used the same model as the Fang and He study with low-contrast ‘invisible’ tools and high-contrast noise images. However, they added a focus of attention for their subjects as well. The invisible images and the noise images were both shown in the periphery of the visual field while in the center of the visual field, subjects were asked to observe a stream of letters. They had subjects perform simple tasks in picking certain letters to assure that their attention remained there while taking using fMRI to map the brain’s responses. Bahrami, et. al. had subjects perform a ‘low attention task,’ such as ‘report all Zs’ and a ‘high attention task,’ such as ‘report blue Zs and white Ns.’ See the diagram below for a basic illustration of the study:

Figure 1. A schematic representation of the display used by Bahrami et al. [6].At peripheral locations, one eye views high-contrast, dynamic noise images that are visible to the observer. At some of the same locations, the other eye views low-contrast tool objects that remain invisible. Both eyes view identical letters at the center of the visual field. The complexity of a letter-monitoring task controls the extent to which peripheral images are attended.

The results:

Bahrami, et. al. found that the peripheral ‘invisible’ images still registered in fMRI when subjects were performing low-attention tasks, but not when their attention was drawn away more insistently. In the low-attention task trials, the subjects were able to tell where the noise-images were flashing, and the invisible tool images had a greater affect on the visual cortex. By contrast, the high-attention task rendered the subjects less able to place the location of the peripheral images and showed less fMRI activation from the invisible tool images. So, Bahrami, et. al. found that ‘a neuronal response need not contribute to visual awareness, even though it is enhanced by visual attention. In short, attention does not guarantee awareness.”

Why is this important?

Subliminal messaging (brief flashing images hidden in other media, such as a picture of a Coca-Cola flashed during a projected movie) is illegal in Britain, but not in the USA. There is continued debate as to whether subliminal messaging is an effective advertising tool, or even possibly a tool for controlling the thoughts and opinions of the general public – imagine if subliminal messages could be used to get people to vote for a political candidate, or to encourage the public to approve of an unpopular war. Subliminal messaging has never been proven to ‘work,’ but it remains a fascinating hypothesis. The Fang and He study showed that there is a neurological response to some images even when the viewer remains unaware of having seen them. Bahrami, et. al. showed that attention affects this brain activity. Essentially, if the subject is focusing attentively on one task, even if it is a visually-based task, the brain will register less about an invisible flashed image. This implies that too much attention paid to the ‘overt message’ could conceivably cancel out the subliminal message. Maybe advertisers should only flash images of their products during ‘low-attention’ viewing tasks (such as the boring part of the movie?) instead of the ‘high-attention’ times (extremely complicated chase sequence?). This is simply speculation – these scientific studies cannot be said to solve the question of subliminal advertising once and for all. As Bahrami says, “What our study doesn't address is whether this would then influence you to go out and buy a product. I believe that it's likely that subliminal advertising may affect our decisions -- but that is just speculation at this point."

Bibliography:

F. Fang and S. He, Cortical responses to invisible objects in the human dorsal and ventral pathways, Nat. Neurosci. 8 (2005), pp. 1380–1385.

B. Bahrami, N. Lavie and G. Rees, Attentional load modulates responses of human primary visual cortex to invisible stimuli, Curr. Biol. 17 (2007), pp. 509–513

J. Braun, Vision: Attending the Visible, Curr. Biol. 17 (2007), pp. R202-R203

University College London (2007, March 9). Subliminal Advertising Leaves Its Mark On The Brain. ScienceDaily. Retrieved February 17, 2009, from http://www.sciencedaily.com /releases/2007/03/070308121938.htm

C. Koch and N. Tsuchiya, Attention and consciousness: two distinct brain processes, Trends Cogn. Sci. 11 (2007), pp. 16–22.

Presentation on Grey Matter and First Episode Psychosis

2009-02-17T06:07:00.001-08:00

A new study has shown there are grey matter deficits in the brains of children ages 7 - 18 with early onset first episode psychosis (FEP). The study featured patients with schizophrenia, bipolar I disorder, and other psychoses.

Grey Matter

Grey matter is a component of the central nervous system, and contains neural cell bodies. The density of grey matter in a particular area corresponds with various abilities.

The top image shows a T1 MRI differentiating between grey and white matter while the bottom image from the New York Times shows the distinction.

Various diseases and disorders have been traced to a lack or atrophy of grey matter, including schizophrenia, bipolar disorder, dyslexia, and MS. These all show decreased amounts of grey matter in specific areas of the brain. In diseases like schizophrenia atrophy occurs over time and affects various areas of the brain.

Schizophrenia and Bipolar I Disorder

Schizophrenia is a mental disorder characterized by abnormalities in perceptions of reality. There are several characteristics of schizophrenia including delusions, hallucinations, disorganized speech, catatonic behavior, and negative symptoms such as attempted flattening (DSM-IV). In general two of these characteristics, which can not be attributed to any other disease or disorder, must be present for 6 months in order for diagnosis.

Bipolar I disorder is a sub-classification of bipolar disorder. Bipolar disorder is characterized by episodes of either mania, an abnormally elevated mood, or depression. Some sufferers may also have mixed episodes, where both symptoms of mania and depression are present at the same time. Bipolar I disorder is characterized by the presence of a manic episode, whether or not the patient has has a depressive or mixed episode (although these are common in bipolar I patients). This is in contrast to bipolar II sufferers who have only had hypomanic (less severe mania) or depressive episodes. The DSM-IV considers there to be a spectrum of bipolar disorders including, bipolar I and II as well as cyclothomia and bipolar n.o.s. (not otherwise specified).

About this study/Why is it important

While past studies have shown grey matter deficits in older patients and people with later onset FEP this was the first study to look specifically at young patients upon first onset. In addition this study focused on a variety of FEP patients, instead of just schizophrenics, a disease where most of this research is concentrated. The study focused on 121 children and adolescents ages 7 - 18, 70 with early onset FEP and 51 control subjects. The subjects' brains were imaged using MRI technology. Follow up care was provided and the patients were diagnosed. Of these diagnoses 25 patients presented with schizophrenia, 20 with bipolar I disorder, and 25 with other psychoses. While all of these patients showed a decrease in grey matter, patients with schizophrenia and bipolar I disorder showed a specific atrophy in the left medial frontal gyrus. In contrast patients with other psychoses showed smaller bilateral grey matter volumes in the insula and right middle occipital gyrus. The shared pathology between schizophrenia and bipolar I disorder may lead to further investigation into the similarities in the diseases as well as the development of new, more targeted medicines that may prevent future grey matter atrophy.

Bibliography

Jansen, J., Reig, S., Parellada, M., et all. (2008). Regional Grey Matter Volume Deficits in Adolescents with First-Episode Psychosis. Journal of the American Academy of Child and Adolescent Psychology. Vol 47 Issue 11, 1311-1320.

Zipursky, R., Lambe, E., Kapur, S., Mikulis, D. (1998). Cerebral Grey Matter Volume Deficits in First Episode Psychosis. Arch Gen Psychiatry, 55, 540-546.

Gur, R., Turestsky, B., Bilker, W., Gur, R. (1999). Reduced Grey Matter Volume in Schizophrenia. Arch Gen Psychiatry, 56, 905-911.

Harrison, P. (1999). The neuropathology of schizophrenia. Brain, Vol 122, No. 4, 593-624.

Steen, R., Mull C. , McClure, R., Hammer, R., Liebermann, J. (2006). Brain Volume in First Episode Schizophrenia. British Journal of Psychiatry, 188, 510-518.

Subliminal Advertising Leaves Its Mark on the Brain

2009-02-16T17:49:00.000-08:00

The ScienceDaily article can be found here.

Grey Matter and Schizophrenia

2009-02-14T06:29:00.000-08:00

Here's the link to the Science Daily article about how lack of grey matter in the brain is linked to schizophrenia and bipolar disorder.

Hope everyone enjoys!

http://www.sciencedaily.com/releases/2009/01/090116073803

Meditation, Mindfulness and Cognitive Flexibility

2009-02-13T10:41:00.000-08:00

Brought to you by Elsevier Journal. Enjoy!

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WD0-4VH333S-1&_user=2670204&_coverDate=01%2F31%2F2009&_alid=863876619&_rdoc=3&_fmt=high&_orig=search&_cdi=6752&_sort=d&_st=4&_docanchor=&_ct=271&_acct=C000058509&_version=1&_urlVersion=0&_userid=2670204&md5=186be3be4027f8eb20bcd970eaf905b5

Test Post

2009-02-03T10:04:00.001-08:00

Blindsight

Link to Brain Diagram

Blindsight Presentation

2009-02-03T05:48:00.000-08:00

Blindsight

Definition of Blindsight
The patient TN reported on in this NPR story is the latest in a series of cases of blindsight. This paradoxical and counterintuitive phenomenon refers to the ability of humans with a loss of primary visual cortex to make visual discriminations in their blind visual fields without awareness of the stimuli they are discriminating.

Measurement of Blindsight
To get around the lack of visual awareness of blind field stimuli researchers ask their patients to guess whether, where, or which one of a small number of stimuli has been presented within the blind visual field. The types of visual discriminations that have been reported are movement, orientation, wavelength (i.e. , color), spatial localization and combinations of these elementary visual features. Accuracy of responses sometimes reached 90% to 100% in various patients (Weiskrantz, 1995). In addition 'affective blindsight' has been demonstrated: patients can sometimes reliably detect the valence of emotional expressions in the absence of any visual awareness of the faces (Tamietto & deGelder, 2008).

Previous Cases:
This phenomenon was first studied in human patients the 1970s by Oxford University based researchers Lawrence Weiskrantz and Elizabeth Warrington. Their patient GY had extensive damage to his left visual cortex which rendered him functionally blind in his right visual field. They were able to demonstrate GY's capacity to perfectly discriminate the direction of motion within his right visual field. Figure 1 of Weiskrantz's review paper shows the different directions of motion that GY was able to accurately mimic with his arm. The grey area is the impaired hemi-field.

Controversies about the cause of blindsight:
Blindsight is most likely to be due to the use of visual pathways outside of the usual geniculostriate ones, connections that are either subcortical or that go directly to extrastriate areas bypassing primary visual cortex. Some brain researchers have objected that the residual visual function of blindsight could be subserved by fragments or islands of intact striate cortex rather than extrastriate cortex (Weiskrantz, 1995). This is unlikely to be the explanation for GY's motion, wavelength, and emotional expression discrimination capacities because a high-resolution MRI scan reveals only a small patch of striate cortex near the back of the brain on the left side, but he does have some remaining striate cortex.

Why TN is a notable case
The damage to TN's striate cortex is much more extensive than GY's. TN suffered two strokes 36 days apart; the first damaged his occipital cortex unilaterally, and the second destroyed the remaining primary visual cortex in the other hemisphere. Figure 1 of de Gelder et al's paper reporting the case shows the extensive primary visual cortex damage. TN is the only available case in the literature with selective bilateral occipital damage. Yet he can successfully navigate down a long corridor with various barriers set in his way, as demonstrated in the video. His blindsight despite total loss of primary visual cortex effectively refutes the remaining islands of functional visual cortex hypothesis. Extra-striate pathways in humans can sustain sophisticated visuo-spatial skills in the absence of perceptual awareness.

What is blindsight good for?
Blindsight is not demonstrated in every patient with loss of primary visual cortex, but when it is present then it the ability can be cultivated through training for rehabilitation. In the case of TN he was unaware of his residual ability to navigate obstacles using visual information. Behaviorally he was blind across the whole visual field. He walked like a blind man, using his stick to track obstacles and requiring guidance by another person when walking around the laboratory buildings during testing. The researchers were able to demonstrate navigation capacity that he did not know that he still retained in the face of such devastating visual loss. In their quick guide to blindsight for the journal Current Biology Stoerig and Cowey (2007) conclude with the speculation that implicit processes in many domains may always survive when explicit representations are damaged, and therefore that rehabilitation programs could always successfully harness the remaining implicit capacities for restitution.

Bibliography:

de Gelder, B., Tamietto, M., van Boxtel, G., Goebel, R. Sahraie, A., van den Stock, J., Steinen, B.M.C., Weiskrantz, L. & Pegna, A. (2008). Intact navigation skills after bilateral loss of striate cortex. Current Biology, 18, 1128-1129. Link

Lamme, V.A.F. (2006). Zap! Magnetic tricks on conscious and unconscious vision. Trends in Cognitive Science, 10, 193-195.

Rees, G. (1999). Consciousness lost and found. Journal of Psychophysiology, 13, 56-60.

Stoerig, P. & Cowey, A. (2007). Blindsight quick guide. Current Biology, 17, 822-824.

Tamietto, M. & deGelder, B. (2008). Affective blindsight in the intact brain: Neural intrahemispheric summation for unseen facial expressions. Neuropsychologia, 46, 820-828.

Weiskrantz, L. ( 1995). Blindsight - Not an island unto itself. Current Directions in Psychological Science, 4, 146-151. Link to Academic Search Premier

NPR Story on Blindsight

2009-02-03T05:46:00.000-08:00

The NPR report on patient TN is available here:
http://www.npr.org/templates/story/story.php?storyId=98590831&sc=emaf