The goals of the study were to examine inhibitory deficits on the antisaccade task in 8- to 20-year olds with youthonset psychosis or attention deficit/hyperactivity disorder (ADHD) and healthy controls and to examine if agerelated changes in performance differed across groups. In addition to the conventional measures of performance, pupillary dilations were used to obtain estimates of phasic and tonic level of arousal. Results showed that the psychosis, but not the ADHD, group had elevated antisaccade error rates; however, variability of error rates was high in all groups. These inhibitory failures were accompanied by a lower level of momentary cognitive effort (as indexed by pupillary dilations). The largest differences between the control and clinical groups were found not in the expected indices of inhibition but in the probability of correcting inhibitory errors and in variability of antisaccade response times, which were correlated with each other. These findings did not appear to be attributable to a deficit in maintaining task instructions in mind in either disorder or lack of motivation in ADHD. Instead, results point to impairments in both clinical groups in sustaining attention on a trial-by-trial basis, resulting in deficits in selfmonitoring. Thus, results show inhibitory deficits in the context of more general attentional impairments in both disorders.
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- Eye movements