The age distributions of the two buy FK506 experimental groups were not statistically different [t49 = 1.32, P > 0.51; Kolmogorov–Smirnov (KS) test]. Typically developing children were excluded if they exhibited symptoms of attention deficit-hyperactivity disorder, had a history of academic or psychiatric difficulties, or were on psychiatric medications, as reported by parents. Children with autism were excluded if they had a history of seizures. For both groups, only children whose non-verbal cognitive functioning was close to or above the average range, as assessed
by the Wechsler Abbreviated Scale of Intelligence (WASI) (Wechsler, 1999; WASI > 80 or higher on the performance IQ scale) were included in this study. Diagnosis of an ASD was confirmed by a research reliable clinician using the Autism Diagnostic Observation Scale (ADOS-G; Lord
et al., 2000), the Autism Diagnostic Interview (ADI-R; Le Couteur et al., 1989) and clinical judgment. Only children who met ADOS and ADI criteria were selleck compound included in the ASD group. Of the 22 children on the autism spectrum, eight had a diagnosis of autism, 11 had a diagnosis of Asperger’s syndrome and three had a diagnosis of pervasive developmental disorder-not otherwise specified (DSM IV; American Psychiatric Association, 2000). Overall, the non-verbal cognitive abilities of the TD children (mean = 105.5; SD = 9.6) and those with ASD (mean = 104.4; SD = 8.4) did not differ (t48 = 0.29, P > 0.77). Before entering into the study, informed written consent was obtained from each child’s parent, and verbal or written assent was obtained from each child. All procedures were approved by the Institutional Review Boards of the City College of the City University of New York as well as the Albert Einstein College of Medicine and conformed to the tenets of Carnitine dehydrogenase the Declaration of Helsinki. A checkerboard pattern subtending 6.4° of visual angle (vertically and horizontally) and with equal numbers of light and dark checks was used throughout this study. Each individual
check subtended 0.8° of visual angle, resulting in a spatial frequency of about 0.625 cycles per degree. Participants were seated in an electromagnetically shielded EEG recording chamber at 70 cm distance from a 21-inch CRT monitor (NEC MultiSync FE2111) with a refresh rate of 60 Hz and a resolution of 1024 by 768 pixels. The maximum luminance of the monitor was set to 117 cd/m2 and background luminance was 57 cd/m2. The participants rested their heads on a comfortable chin-rest, which ensured proper viewing distance. Each participant underwent three runs for each stimulus condition (Full-Range VESPA, Magno VESPA and VEP) with presentation of stimuli in the center of the screen as well as 6.2° to the right. All runs were of 120 s duration. To reduce the amount of task-switching, we presented all runs at a given eccentricity consecutively. For each participant it was randomly assigned at which eccentricity the stimuli were presented first.