Fast and slow reaction times and associated ERPs in patients with schizophrenia and controls.
A number of studies have examined across-trial averaged late component. Event Related Potentials (EPR) and Reaction Times (RT) in response to multiple target stimuli. In this study, within-trial relatively fast and slow sub averages are additionally examined, in 20 patients with schizophrenia and 20 age and sex matched controls. A conventional auditory oddball paradigm. Across-trial ERP average analysis showed smaller N200 amplitude and delayed latency (but larger P200 amplitude) in patients with schizophrenia compared with controls. Within-trial ERP analysis revealed a number of additional findings. Controls showed distinctive differences in fast compared with slow ERP sub averages (smaller P200 amplitude, increased N200/P300 amplitudes and earlier latencies). The schizophrenic group on the other hand, showed relatively similar fast versus slow subaverages (no differences in P200 amplitude and N200 latency). In addition, between-group (within-trial) analyses highlighted significant differences in earlier stages of processing (compared with across-trial averages) in both fast and slow subaverages (increased N100 amplitude in controls). The complementary within-trial (compared with across-trial) data are interpreted with respect to a possible disturbance in inhibitory function in patients with schizophrenia.
Department of Psychological Medicine, Westmead Hospital, NSW, f2p4ralia. h.bahramali@neuro.wsahs.nsw.gov.au
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Bahramali
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Gordon
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Li
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Rennie
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Wright
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Meares
D000328:Adult; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance; D011930:Reaction Time; D012559:Schizophrenia / Q000503:physiopathology*; D013997:Time Factors