title: Facial identity recognition in children with autism spectrum disorders revealed by P300 analysis: a preliminary study.
abstract: BACKGROUND
  To reveal the neural substrate of communication difficulties in children with autism spectrum disorders (ASDs), we investigated the P300 component of event-related potentials (ERPs) as represented by the average of electroencephalography findings time-locked to events and behavior. Because the P300 amplitude influences attentional resource allocation during discrimination, the component elicited during perception of known and unknown faces should indicate familiarity processing.
  
  
  RESULTS
  Nine typically developing children (TD) and nine children with ASDs participated in this study (Experiment 1). The P300 amplitude in TD children was significantly larger during familiar face perception than during unfamiliar face perception (p<0.01). However, there was no evidence of familiarity effect in children with ASDs. In three children with ASDs, we also assessed the P300 amplitude during perception of a therapist's face one month before (baseline), a few days before and after social skills training (SST) sessions (Experiment 2). To evaluate the effect of familiarity on facial identity processing, we analyzed the therapist/unknown ratio of P300 amplitudes related to the face discrimination task as an index. The ratio was larger after SST sessions than before, but there was no difference in the ratio between baseline and before SST assessments.
  
  
  CONCLUSIONS
  The P300 might be influenced by attentional resource allocation depending on the stage of learning face identification in children with ASDs. We speculate that this approach to evaluating brain responses during facial identity recognition could be used as a tool to clarify children's communication difficulties.
authors: National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Japan. agunji@ncnp.go.jp
authors: Atsuko
authors: A
authors: Gunji
authors: Takaaki
authors: T
authors: Goto
authors: Yosuke
authors: Y
authors: Kita
authors: Ryusuke
authors: R
authors: Sakuma
authors: Naomi
authors: N
authors: Kokubo
authors: Toshihide
authors: T
authors: Koike
authors: Kotoe
authors: K
authors: Sakihara
authors: Makiko
authors: M
authors: Kaga
authors: Masumi
authors: M
authors: Inagaki
mesh_terms: D000704:Analysis of Variance; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000503:physiopathology*; D004192:Discrimination, Psychological; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D021641:Recognition, Psychology / Q000502:physiology*