November 25, 2007
Neural correlates of face object recognition in young children with autism spectrum disorder
Mihaela Chraif
Ejop Editor
Our Interviewed: Assist. prof. Leslie Carver from San Diego University, California, U.S.A.
Dr. Carver studies the brain basis of cognitive and social developmental change in the transition from infancy to the early toddler years. Near the end of the first year of life, infants begin to develop the ability to remember information over very long intervals. Dr. Carver’s research examines changes in the brain that allow this long-term memory to develop.
In addition to developments in cognition, infants at the end of the first year of life form long-lasting relationships with caregivers, and begin to use caregivers as a source of information about how to behave. For example, in the last half of the first year of life, infants begin to look to their parents’ facial expressions to understand how to interpret unusual situations that they encounter. Dr. Carver conducts research on changes in the brain that are associated with such changes in social behavior. Thus, is conducting a research study to find out more about changes in infant’s and young children’s brain responses to familiar and unfamiliar people with development. Children between the ages of 6 months and 4 years old may participate.
At different points in this age range, children are differentially interested in familiar and unfamiliar people. For example, one-year-olds are often afraid of strangers, whereas preschoolers and very young infants are often interested in new people. The purpose of this study is to understand how infants’ and young children’s brain activity changes in response to familiar and unfamiliar people with development.
EJOP: Can you tell us about your research area in California?
Prof. Carver: My interested is in brain bases in cognitive social development of children, children developing normally, children who have autism, and children at risk for autism. I also study memory development, the nature of early impairments in social cognition in autism, neural correlates of face object recognition in young children with autism spectrum disorder, and now I’m studying how babies and young children process faces and how the processing faces are related with social development.
EJOP: What can you tell us about latest your studies in autism in USA?
Prof. Carver: Well, mostly what I am doing right now is a kind of work with children developing autism and behavior characteristic of autism. We are interested in how to early diagnosis early autism and to understand the things are involved in developing autism. I am also interested in face processing- inattention to faces is one of the most reliable early predictors of autism, emotion recognition- people with autism have difficulty understanding and identifying others’ emotions and social cognition- people with autism do not effectively regulate their behavior according to feedback from social interactions.
EJOP: What can you tell us about face processing in autism?
Prof. Carver: In typically developing infants, the face holds particular significance and provides non verbal information important for communication and survival. The neural systems that mediate face processing and recognition rapidly develop during the first 6 months of life. This ability offers the possibility that face recognition impairments may be one of the earliest indicators of abnormal brain development in autism. Throughout development, children with autism attend to faces less, and differently than other children normal developing.
EJOP: How do you explain that the Facial Expressions are not processed by those Diagnosed with Autism?
Prof. Carver: An example could be a research study in which were compared the brain activity of 23 typically developing children with 23 children diagnosed with high-functioning autism. Both groups of children were asked to examine a series of facial expressions, like angry, fearful, happy, and neutral. In half of the faces the eyes were averted away from the child and in the other half of the pictures the face stared at the child. When the normally developing children viewed the direct gaze faces a part of the brain called the ventrolateral prefrontal cortex (VLPFC) was activated, a brain region known for evaluating emotion. When they viewed the averted gaze face the brain activation in this same region was greatly reduced. In the children diagnosed with autism the VLPFC did not show activity for either face suggesting that this group do not process visual cues from another person’s eyes. Researchers believe these findings suggest an explanation why someone diagnosed with autism have trouble picking up on social cues like body language and gestures.
EJOP: Do you think that Not Responding To Name May Be Sign of Autism?
Prof. Carver:A child's failure to respond to his or her name at one year of age may be an early warning sign of autism or other developmental problems. There are many studies, involving children age one whose older siblings had autism, and who were therefore considered at risk. In a most recent study a number of 101 children age one whose older siblings had autism were compared to 46 infants of the same age who were not believed to be at high risk of developing the disorder. With each child seated at a table with a small toy, a researcher walked behind and called his or her name in a clear voice. If the child did not respond after three seconds, the name was called again no more than twice. They found that three-quarters of those who did not respond to their name at age 12 months had developmental problems at age 2. While the test will not find all children at risk for developmental problems, it is easy to administer, takes few resources and doctors might want to include it in child check-ups at age one. The finding is significant because earlier identification of autism offers the possibility of early intervention, which holds promise for improving outcomes.
EJOP: Why autistic children do not imitate or empathize?
Prof. Carver: New imaging research shows that impairments in autistic children's ability to imitate and empathize can be linked to dysfunction in the brain's mirror-neuron system.
Mirror neurons fire when an individual performs an action with a goal in mind. They also fire when one watches another individual perform that same action. Neuroscientists believe this "mirroring" is the neural mechanism by which the actions, intentions and emotions of other people can be automatically understood. Individuals with autism can't rely on this system to read the minds of other people. Symptoms of autism include varying levels of difficulty with social interaction, including verbal and nonverbal communication, imitation, and empathy. To measure mirror-neuron activity, the research used functional magnetic resonance imaging (fMRI) in 12 high-functioning children with autism as they viewed and imitated faces depicting several emotional expressions, such as anger, fear, happiness or sadness. The researchers found that, as expected, the level of brain activity in "mirroring" areas was related to the children's tendency to spontaneously imitate others, as well as to empathize with them. Specifically, significant negative correlations were found between symptom severity on the imitation items and activity in the mirror area located in the brain's right inferior frontal gyrus.
EJOP: What are the tendencies in the study of the autism and emotions in U.S.A., now?
Prof. Carver: Autism is a disorder characterized by specific impairments in processing social and emotional information, evident in social orienting, attention and emotional responses to the others. Now, the recent studies are based on processing the emotional expression using electrical brain responses to an emotional facial expression; measures of brain electrical activity in response to specific stimulus; emotion recognition and autism spectrum disorders; and emotion recognition and typically development of children.