November 6, 2010

Long-term Memories The Good, the Bad, and the Ugly

From The Dana Foundation

Editor’s note: Traumatic memories haunt the lives of people suffering from post-traumatic stress disorder, or PTSD, and other illnesses. Fortunately, recent research into the changeability of long-term memories may someday develop into treatments for such individuals. But before this can happen, writes Cristina Alberini, Ph.D., of Mount Sinai School of Medicine, researchers must determine just how effectively the fear associated with older memories—especially those involved in PTSD—can be reduced and for how long. Researchers must also address the ethical issues that go hand in hand with modifying memory.

For more than a century, clinicians, psychologists, and biologists have worked to understand the mechanisms underlying the formation and storage of long-term memories. Recently, scientists found that when a stored memory is recalled, it becomes sensitive to disruption for a limited time.1,2 This finding indicates that it might be possible to weaken or even erase memories of traumatic experiences that become uncontrollably intrusive in post-traumatic stress disorder (PTSD). This possibility has drawn great interest from scientific and clinical communities, as well as from nonscientists, who became interested in its potential clinical applications; furthermore, it raised ethical concerns.

Many ethical questions and debates about treatments designed to weaken memories may reflect the still poor understanding of how memory recall or reactivation results in memory fragility and the many unknowns surrounding its temporal boundaries. Whereas the study of animal models and healthy humans has provided some knowledge about post-recall memory disruption, data on the use of such disruption to treat PTSD symptoms are still conflicting. The strengthening of memory with the passage of time, the resilience of strong memories to disruption, and the specific aspects of memory that become sensitive to disruption raise questions about the limitations of this approach and warrant more research. Here, we will look at how we form memories of an emotional event and how these memories become fragile after recall. That will help us consider the potential, limitations, and ethics of disrupting memories of emotion.

Read the entire article

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October 28, 2010

The Vegetative State and the Science of Consciousness

Article in British Journal for the Philosophy of Science

N. Shea, T. Bayne

Abstract

Consciousness in experimental subjects is typically inferred from reports and other forms of voluntary behaviour. A wealth of everyday experience confirms that healthy subjects do not ordinarily behave in these ways unless they are conscious. Investigation of consciousness in vegetative state patients has been based on the search for neural evidence that such broad functional capacities are preserved in some vegetative state patients. We call this the standard approach. To date, the results of the standard approach have suggested that some vegetative state patients might indeed be conscious, although they fall short of being demonstrative. The fact that some vegetative state patients show evidence of consciousness according to the standard approach is remarkable, for the standard approach to consciousness is rather conservative, and leaves open the pressing question of how to ascertain whether patients who fail such tests are conscious or not. We argue for a cluster-based ‘natural kind’ methodology that is adequate to that task, both as a replacement for the approach that currently informs research into the presence or absence of consciousness in vegetative state patients and as a methodology for the science of consciousness more generally.

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October 22, 2010

What research paradigms have cognitive psychologists used to study “False memory,” and what are the implications of these choices?

K. Pezdek, S. Lam
Article in Consciousness and Cognition

Abstract
This research examines the methodologies employed by cognitive psychologists to study “false memory“, and assesses if these methodologies are likely to facilitate scientific progress or perhaps constrain the conclusions reached. A PsycINFO search of the empirical publications in cognitive psychology was conducted through January, 2004, using the subject heading, “false memory.” The search produced 198 articles. Although there is an apparent false memory research bandwagon in cognitive psychology, with increasing numbers of studies published on this topic over the past decade, few researchers (only 13.1% of the articles) have studied false memory as the term was originally intended—to specifically refer to planting memory for an entirely new event that was never experienced in an individual’s lifetime. Cognitive psychologists interested in conducting research relevant to assessing the authenticity of memories for child sexual abuse should consider the generalizability of their research to the planting of entirely new events in memory.

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March 5, 2008

Neuropsychologia special issue: Consciousness & Perception

Neuropsychologia hosts a special issue in relation to the work of Larry Weiskrantz. It contains a densely packed number of articles on the topic of blindsight and hindsights.

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Gene variants may increase risk of anxiety disorders

anx.jpegFrom physorg: Massachusetts General Hospital (MGH) researchers – in collaboration with scientists at the University of California at San Diego and Yale University – have discovered perhaps the strongest evidence yet linking variation in a particular gene with anxiety-related traits. In the March issue of Archives of General Psychiatry, the team describes finding that particular versions of a gene that affects the activity of important neurotransmitter receptors were more common in both children and adults assessed as being inhibited or introverted and also were associated with increased activity of brain regions involved in emotional processing.

“We found that variations in this gene were associated with shy, inhibited behavior in children, introverted personality in adults and the reactivity of brain regions involved in processing fear and anxiety,” says Jordan Smoller, MD, ScD, of the MGH Department of Psychiatry, the report’s lead author. “Each of these traits appears to be a risk factor for social anxiety disorder, the most common type of anxiety disorder in the U.S.”

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October 25, 2007

New issue: Personality and Individual Differences

A new issue of PID is out, including articles on borderline and self-regulation, black anti-white attitudes and personality, and stress reactions and personality.

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October 18, 2007

How Schizophrenia Develops: Major Clues Discovered

schizo.jpegSchizophrenia may occur, in part, because of a problem in an intermittent on/off switch for a gene involved in making a key chemical messenger in the brain, scientists have found in a study of human brain tissue. The researchers found that the gene is turned on at increasingly high rates during normal development of the prefrontal cortex, the part of the brain involved in higher functions like thinking and decision-making — but that this normal increase may not occur in people with schizophrenia.

The gene, GAD1, makes an enzyme essential for production of the chemical messenger, called GABA. The more the gene is turned on, the more GABA synthesis can occur, under normal circumstances. GABA helps regulate the flow of electrical traffic that enables brain cells to communicate with each other. It is among the major neurotransmitters in the brain.

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September 6, 2007

New insights into OCD

abnormal psych,personality,psychiatry — thomasr @ 3:48 pm

ocd.jpegObsessive-compulsive disorder (OCD) is a common debilitating psychiatric disorder, yet the cause of OCD is unknown and few effective treatments are available. A recent study of mutant mice reveals a novel mechanism leading to OCD-like behaviors in mice and suggests potential new therapeutic strategies.

By Dr. Jing Lu and Dr. Guoping Feng, in Scitizen.com

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August 26, 2007

Anhedonia — great intro and review at Medscape.com

abnormal psych,emotions — thomasr @ 3:29 pm

anhedonia.jpegMedscape.com has a very nice article on anhedonia, which is described as “an inability to experience pleasure from normally pleasurable life events such as eating, exercise, and social or sexual interaction”. Here, we bring an excerpt from the article.

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When the Need to Belong Goes Wrong

socialphobia.jpegWhen the Need to Belong Goes Wrong: The Expression of Social Anhedonia and Social Anxiety in Daily Life

People possess an innate need to belong that drives social interactions. Aberrations in the need to belong, such as social anhedonia and social anxiety, provide a point of entry for examining this need. The current study used experience-sampling methodology to explore deviations in the need to belong in the daily lives of 245 undergraduates. Eight times daily for a week, personal digital assistants signaled subjects to complete questionnaires regarding affect, thoughts, and behaviors.

As predicted, higher levels of social anhedonia were associated with increased time alone, greater preference for solitude, and lower positive affect. Higher social anxiety, in contrast, was associated with higher negative affect and was not associated with increased time alone. Furthermore, greater social anxiety was associated with greater self-consciousness and preference to be alone while interacting with unfamiliar people.

Thus, deviations in the need to belong affect social functioning differently depending on whether this need is absent or thwarted.

Psychologial Science

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August 2, 2007

Ventromedial moral

ventromedialpfc.jpegDoes the ventromedial prefrontal cortex play a role in personal moral judgment? Medscape.com has a nice report on 7 patients with lesions in the ventromedial prefrontal cortex that find that “the ventromedial prefrontal cortex is necessary to oppose personal moral violations, possibly by mediating anticipatory, self-focused, emotional reactions that may exert strong influence on moral choice and behavior.”

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Trating panic disorders — an update

abnormal psych,psychiatry — thomasr @ 4:34 am

Psychotherapy and benzodiazepines have been reported as effective panic disorder treatments individually with different benefits and disadvantages. Does combining the therapies offer extra advantages? Medscap.com brings a report.

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May 24, 2007

Visual hallucinations? Draw it!

epilepsy_brain.jpgVisual (and other non-visual) hallucinations sometimes occur during epileptic seizures. A relatively straightforward but little used method to describe these experiences is to ask the sufferer to draw the hallucinations — even as they occur.

According to G.D. Schott, in an article in the latest issue of Brain, such descriptions not only not only serve as tools to understand the sufferer and symptoms; they can also be used for differential diagnosis. 

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March 7, 2007

Bipolar depression — treatment and perils

abnormal psych,psychiatry — thomasr @ 3:34 pm

Why is it seemingly more difficult to treat bipolar depression than bipolar mania? Why does it seem so hard to get the FDA to approve medications for bipolar depression? Medscape brings the latest news.

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February 20, 2007

Biological Psychiatry — Special issue on autism

autist.gifThe journal Biological Psychiatry has a special issue on the autism spectrum, its diagnosis and treatment.

It is a comprehensive yet diverse collection of multidisciplinary treatment of the issue, containing articles onautism and phenotypic homogeneity; cortical layering and thickness; cortical dysfunction; executive function and gaze fixation.

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November 19, 2006

Altered cognition and emotion in depersonalization disorder

depersonal.jpgDepersonalization Disorder (DPD) is a dissociative disorder in which sufferers are affected by persistent feelings of depersonalization. The symptoms include a sense of automation, feeling a disconnection from one’s body, and difficulty relating oneself to reality. In a recent study Medford et al. reports that patients with DPD do not process emotionally salient material in the same way as healthy controls, in accordance with their subjective descriptions of reduced or absent emotional responses

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January 24, 2005

Shadow of perception in schizophrenia

abnormal psych — thomasr @ 10:46 am

In the latest Nature Neurosicence, Jane Qiu reviews some of the recent theories of schizophrenia indicating that the desease is caused not by any particular brain region, but rather a global across the board problem in neuronal circuit integrity. Link

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