Poor recognition of 'self' found in high functioning people with autism

HOUSTON -- (February 6, 2008) -- Contrary to popular notions, people atthe high end of the autism spectrum disorder continuum suffer most froman inability to model "self" rather than impaired ability to respond toothers, said Baylor College of Medicine researchers in a report thatappear in the journal Neuron.This inability to model "self" can disrupt an individual's ability tounderstand the world as a whole, said Dr. P. Read Montague Jr.,professor of neuroscience, and director of the Human Neuroimaging Laband the Computational Psychiatry Unit at BCM. "It's an interestingdisconnect."Autism SignatureUsing a functional magnetic resonance imaging (fMRI) scanner, Montagueand his colleagues scanned the brains of people considered "highfunctioning" autistics because they have normal or high normalintelligence quotients but many of the symptoms of people with autism.During this procedure, the researchers identified a pattern of activityor "signature" in the brain that identified those with autism. The levelof activity correlates with the severity of the autistic symptoms. Theless activity there is, the more serious the symptoms. The finding couldlead to a test to speed diagnosis."We are very excited about the usefulness of the hyperscanningtechnology and economic games as new tools to probe autism. Our hope isthat these same approaches can be used to probe a wide range ofpsychopathologies," said Dr. Pearl Chiu, first author on the study andan assistant professor in the departments of neuroscience and psychiatryand behavioral sciences at BCM.HyperscanningTo understand the behavioral patterns of people with autism spectrumdisorder, Montague and his colleagues used a technique calledhyperscanning, which enabled them to scan two brains simultaneouslywhile the research subjects played a trust game. Hyperscanning wasdeveloped in Montague's laboratory.In the trust game, one player receives an amount of money and then sendswhatever amount he or she wants to the other player via computermessage. The amount sent is tripled and the player at the other end thendecides how much of the tripled amount to send back. The game hasseveral rounds.During this interaction, Montague and his colleagues evaluated thebrains' response by watching bright spots in the brain that representincreased blood flow and thus brain activity. Prior work had shown thatduring the trust game, most of the activity occurs in an area called thecingulate cortex.Study StructureTo hone their picture of the "self" response in that part of the brain,Montague and his colleagues had 81 athletes (football, baseball andsoccer players as well as members of the Houston Ballet) take part in animagining task. They watched clips of various athletic activities whilein the scanner. They then imagined themselves performing thoseactivities. The pattern of activity in the cingulate cortex during that"imagining" reflected the "self" response.Later the scientists identified the same "self" response in thecingulate cortices of normal subjects when they decided how much moneyto send to the other person. The pattern contrasted with the "other"response seen when the actions of their partner in the trust game wererevealed to them.The researchers then brought in 18 adolescent males with highfunctioning autism to play the game. Montague and his colleaguesdetermined that the subjects understood the game and helped them adjustto the scanning procedure."It was the first time an autistic kid had been scanned in a socialexchange," said Montague.Differences Found in Cingulate CortexThe adolescents did not play the game differently from their partners,who were taken from a population of similar teens who did not haveautism. They made similar amounts of money overall and round by round.However, when the researchers scanned the brains of the youngsters withautism during the trust game, they found that the youngsters' "self"responses were dim compared to those of normal subjects. Not only that,but the more serious the subject's autistic symptoms, the dimmer theresponse.The response occurred in the cingulate cortex. In a normal "self"response there, the brightest area was in the middle of that area of thebrain. That response was significantly less in the brains of theyoungsters with autism."They cognitively understood the game," said Montague. "It's not thatthey don't understand the game. It's that there is a very low level of'self' response. It's impaired in them and the degree to which it ismissing correlates with their symptom severity. The more you are missingthe self response, the more autistic you are."To have a good self concept, you have to be able to decide if theshared outcome is due to the other person or due to you," said Montague."If people can't see themselves as a distinct entities at deeper levels,there is a disconnect."He believes that the problem occurs at an unconscious level. He hopes touse the imagining technique in the future to scan the brains of peoplewith autism whose intelligence is less than that of those in this firstexperiment."The genius of this study was to recognize the primary deficit with thisspectrum of disorders," said Dr. Michael Friedlander, chair ofneuroscience at BCM. "Then they took that information dealing with thedeficit social cognition and invented a new kind of experiment andtechnology to probe it."Others who took part in this study included Drs. Pearl H. Chiu, M. AminKayali, Kenneth T. Kishida and Damon Tomlin of BCM and Drs. Laura G.Klinger and Mark R. Klinger of the University of Alabama at Tuscaloosa.Funding for this work came from The Kane Family Foundation, The DanaFoundation and Autism Speaks, the National Institute on Drug Abuse, theNational Institute of Neurological Disorders and Stroke, The AngelWilliamson Imaging Center, and the American Psychological Association.