Multiple studies have demonstrated prefrontal dysfunction among
schizophrenics. The prefrontal cortex does not function in isolation, but
instead relies on extensive connections with other brain areas. Functional
relationships between cortical areas were assessed by calculating the
coherences between different scalp electroencephalogram (EEG) signals
recorded from 13 unmedicated male patients with schizophrenia and 9 normal
male subjects. Alpha-band coherences linked to prefrontal areas in
schizophrenic patients were about the same as those of normal controls when
subjects were cognitively "at rest," but they were reduced for certain
electrode pairs in the former group when performing the degraded-stimulus
continuous performance test. Most of these findings were not accounted for
by changes in alpha power, suggesting that "cortical circuits" extending
beyond prefrontal areas may be disrupted in schizophrenia.Abstract Teaser