Friendly to a fault, yet tense: Personality traits traced in brain
The severity of abnormalities in insula (red structure near bottom of brain), gray matter volume (left) and brain activity (right) predicted the extent of aberrant personality traits in Williams syndrome patients -- as reflected in their scores (red dots) on personality rating scales (WSPP). Credit: Karen Berman, M.D., NIMH Clinical Brain Disorders Branch
A personality profile marked by overly gregarious yet anxious behavior is rooted in abnormal development of a circuit hub buried deep in the front center of the brain, say scientists at the National Institutes of Health. They used three different types of brain imaging to pinpoint the suspect brain area in people with Williams syndrome, a rare genetic disorder characterized by these behaviors. Matching the scans to scores on a personality rating scale revealed that the more an individual with Williams syndrome showed these personality/temperament traits, the more abnormalities there were in the brain structure, called the insula.
"Scans of the brain's tissue composition, wiring, and activity produced converging evidence of genetically-caused abnormalities in the structure and function of the front part of the insula and in its connectivity to other brain areas in the circuit," explained Karen Berman, M.D., of the NIH's National Institute of Mental Health (NIMH).
"This line of research offers insight into how genes help to shape brain circuitry that regulates complex behaviors such as the way a person responds to others and thus holds promise for unraveling brain mechanisms in other disorders of social behavior," said NIMH Director Thomas R. Insel, M.D.
Long distance connections, white matter, between the insula and other parts of the brain are aberrant in Williams syndrome. Neuronal fibers of normal controls (left) extend further than those of Williams syndrome patients (right). Picture shows diffusion tensor imaging data from each patient superimposed on anatomical MRI of the median patient. Credit: Karen Berman, M.D., NIMH Clinical Brain Disorders BranchWilliams syndrome is caused by the deletion of some 28 genes, many involved in brain development and behavior, in a particular section of chromosome 7. Among deficits characteristic of the syndrome are a lack of visual-spatial ability such as is required to assemble a puzzle and a tendency to be overly-friendly with people, while overly anxious about non-social matters, such as spiders or heights. Many people with the disorder are also mentally challenged and learning disabled, but some have normal IQs.
Previous imaging studies by the NIMH researchers found abnormal tracts of the neuronal fibers that conduct long-distance communications between brain regions -- likely resulting from neurons migrating to the wrong destinations during early development.
Evidence suggests that genes influence our temperament and the development of mental disorders via effects on brain circuits that regulate behavior. Yet direct demonstration of this in humans has proven elusive. Since the genetic basis of Williams syndrome is well known, it offers a unique opportunity to explore such effects with neuroimaging, reasoned the researchers.
Although the insula had not previously been studied in such detail in the disorder, it was known to be related to brain circuitry and certain behaviors, such as empathy, which is also highly prominent in the disorder. Berman and colleagues hypothesized that the insula's anatomy, function and connectivity would predict patients' scores for Williams syndrome-associated traits on personality rating scales. Fourteen intellectually normal Williams syndrome participants and 23 healthy controls participated in the study.
Magnetic resonance imaging (MRI) revealed that patients had decreased gray matter the brain's working tissue in the bottom front of the insula, which integrates mood and thinking. By contrast, they had increased gray matter in the top front part of the insula, which has been linked to social/emotional processes.
Diffusion tensor imaging, which by detecting the flow of water in nerve fibers can identify and measure the connections between brain areas, showed reduced white matter the brain's long-distance wiring between thinking and emotion hubs.
Tracking radioactively-tagged water in order to measure brain blood flow at rest, via positron emission tomography (PET), exposed activity aberrations consistent with the MRI abnormalities. The PET scans also revealed altered functional coupling between the front of the insula and key structures involved in thinking, mood and fear processing. These structural and functional abnormalities in the front of the insula correlated with the Williams syndrome personality profile.
"Our findings illustrate how brain systems translate genetic vulnerability into behavioral traits" explained Berman.
More information: The Williams syndrome chromosome 7q11.23 hemideletion confers hypersocial, anxious personality coupled with altered insula structure and function. Jabbi M, Kippenhan JS, Kohn P, Marenco S, Mervis CB, Morris CA, Meyer-Lindenberg A, Berman KF. Proc Natl Acad Sci. 2012 Mar 12. [Epub ahead of print] PMID: 22411788
Provided by National Institutes of Health
- Scientists learn how brains process images of faces May 12, 2010 | not rated yet | 0
- Depression gene may weaken mood-regulating circuit May 09, 2005 | not rated yet | 0
- Biofeedback for your brain? Sep 09, 2010 | not rated yet | 0
- Barrow scientist leads insula research Jul 07, 2010 | not rated yet | 0
- 2 genes influence social behavior, visual-spatial performance in people with Williams syndrome Feb 11, 2009 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
Marie Curie's leukemia
May 13, 2013 Does anyone know what might be the cause of Marie Curie's cancer
- More from Physics Forums - Medical Sciences
More news stories
Study shows premature birth interrupts vital brain development processes leading to reduced cognitive abilities
Researchers from King's College London have for the first time used a novel form of MRI to identify crucial developmental processes in the brain that are vulnerable to the effects of premature birth. This new study, published ...
Neuroscience 24 minutes ago | not rated yet | 0 |
While the effects of acute stroke have been widely studied, brain damage during the subacute phase of stroke has been a neglected area of research. Now, a new study by the University of South Florida reports that within a ...
Neuroscience 2 hours ago | not rated yet | 0 |
Over the past few decades, neuroscientists have made much progress in mapping the brain by deciphering the functions of individual neurons that perform very specific tasks, such as recognizing the location ...
Neuroscience 5 hours ago | 5 / 5 (5) | 0 |
For combat veterans suffering from post-traumatic stress disorder, 'fear circuitry' in the brain never rests
Chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety. Previous imaging studies of people with post-traumatic stress disorder, or PTSD, have shown that these brain regions can over-or ...
Neuroscience May 18, 2013 | 5 / 5 (1) | 0 |
The neural machinery underlying our olfactory sense continues to be an enigma for neuroscience. A recent review in Neuron seeks to expand traditional ideas about how neurons in the olfactory bulb might encode information about ...
Neuroscience May 17, 2013 | 4 / 5 (1) | 0 |
Salamanders' immune systems are key to their remarkable ability to regrow limbs, and could also underpin their ability to regenerate spinal cords, brain tissue and even parts of their hearts, scientists have ...
24 minutes ago | not rated yet | 0 |
Researchers have pinpointed a catalytic trigger for the onset of Alzheimer's disease – when the fundamental structure of a protein molecule changes to cause a chain reaction that leads to the death of neurons ...
24 minutes ago | not rated yet | 0 |
Whooping cough has exploded in the United States and some other developed countries in recent decades, and many experts suspect ineffective childhood vaccines for the alarming resurgence.
24 minutes ago | not rated yet | 0 |
(HealthDay)—For young adults needing either a chest or abdominopelvic computed tomography (CT), the short-term risk of death from underlying morbidity is greater than the long-term risk of radiation-induced ...
1 hour ago | not rated yet | 0
New research suggests that for some hospitalized ICU patients on mechanical ventilators, using headphones to listen to their favorite types of music could lower anxiety and reduce their need for sedative medications.
1 hour ago | not rated yet | 0 |
A new study conducted by researchers at the Child Study Center at NYU Langone Medical Center found men diagnosed as children with attention-deficit/hyperactivity disorder (ADHD) were twice as likely to be obese in a 33-year ...
3 hours ago | not rated yet | 0 |