Background: Previous work with schizophrenic children disclosed deficits on two continuous performance tests (CPTs) and ERP indices of reduced attentional resource allocation.
Methods: The two CPTs were administered to adult schizophrenics and matched control subjects. The simple CPT required only that the subject respond whenever the target digit was displayed.
Event-related potentials (ERPs) were recorded from adult schizophrenics and age- and education-matched normal controls during performance of an idiom recognition task involving judgments of the meaningfulness of idiomatic, literal, and nonsense phrases. Schizophrenics produced more errors and had prolonged reaction times while attempting to correctly differentiate meaningful from meaningless phrases. An ERP correlate of that deficit was a larger than normal N400 to idioms and literals, with no difference in N400 amplitude to nonsense phrases.
View Article and Find Full Text PDFVisual information processing in children with attention deficit hyperactivity disorder (ADHD) was studied using event-related potentials recorded during two versions of the Continuous Performance Task (CPT). ADHD children made more errors, and had longer reaction times than normal children on both the single- and dual-target CPT. Event-related potential waveforms were normal in the ADHD children with reference to early processing stages, i.
View Article and Find Full Text PDFEur Arch Psychiatry Clin Neurosci
October 1995
This paper summarizes retrospective and cross-sectional neurobehavioral studies of schizophrenic children. Retrospective studies of schizophrenic children reveal that during early childhood, prior to the first onset of schizophrenic symptoms, most schizophrenic children showed delays in language acquisition and/or impairments and delays in visual-motor coordination. These impairments appear to be developmental delays rather than fixed neurobehavioral impairments, because cross-sectional studies conducted when the children are at least 10 years of age, after the first onset of psychosis, fail to detect the same deficits.
View Article and Find Full Text PDFEvent-related potentials were recorded from outpatient adult schizophrenics receiving maintenance doses of neuroleptics and from normal control subjects during performance of a reaction time task and a complex visual discrimination task, the Span of Apprehension. Difference potentials were computed to isolate endogenous activity associated with the processing demands of the Span task. Schizophrenics produce significantly less early endogenous negative activity than do normal subjects.
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