TY - JOUR
T1 - Steady-state visually evoked potential topography during the continuous performance task in normal controls and schizophrenia
AU - Silberstein, Richard B.
AU - Line, Per
AU - Pipingas, Andrew
AU - Copolov, David
AU - Harris, Philip
PY - 2000/5/1
Y1 - 2000/5/1
N2 - Objectives: To examine the latency topography of the steady-state visually evoked potential (SSVEP) in patients diagnosed with schizophrenia and normal controls while undertaking a visual vigilance task. Methods: Twenty patients diagnosed with schizophrenia and 18 normal controls performed the A-X version of the continuous performance task (CPT A-X) where subjects are required to press a micro-switch on the unpredictable appearance of an 'X' that had been preceded by an 'A.' Brain electrical activity was recorded from 64 scalp sites and a 13 Hz spatially uniform visual flicker presented with the task was used to elicit a steady-state visually evoked potential (SSVEP). Results: Following the appearance of the 'A' and 'X,' the control group demonstrated a transient SSVEP latency reduction at parietal and prefrontal sites. By contrast, the patients group showed no such SSVEP latency reduction. The prefrontal SSVEP latency changes in the 500 ms interval following the appearance of the 'X' were correlated with mean individual reaction time in both populations. Conclusions: We suggest that the SSVEP latency reduction may index excitatory processes and that the absence of prefrontal SSVEP latency reduction in schizophrenic patients may be a manifestation of reduced prefrontal activity or 'hypofrontality' observed with other neuroimaging modalities. (C) 2000 Elsevier Science Ireland Ltd.
AB - Objectives: To examine the latency topography of the steady-state visually evoked potential (SSVEP) in patients diagnosed with schizophrenia and normal controls while undertaking a visual vigilance task. Methods: Twenty patients diagnosed with schizophrenia and 18 normal controls performed the A-X version of the continuous performance task (CPT A-X) where subjects are required to press a micro-switch on the unpredictable appearance of an 'X' that had been preceded by an 'A.' Brain electrical activity was recorded from 64 scalp sites and a 13 Hz spatially uniform visual flicker presented with the task was used to elicit a steady-state visually evoked potential (SSVEP). Results: Following the appearance of the 'A' and 'X,' the control group demonstrated a transient SSVEP latency reduction at parietal and prefrontal sites. By contrast, the patients group showed no such SSVEP latency reduction. The prefrontal SSVEP latency changes in the 500 ms interval following the appearance of the 'X' were correlated with mean individual reaction time in both populations. Conclusions: We suggest that the SSVEP latency reduction may index excitatory processes and that the absence of prefrontal SSVEP latency reduction in schizophrenic patients may be a manifestation of reduced prefrontal activity or 'hypofrontality' observed with other neuroimaging modalities. (C) 2000 Elsevier Science Ireland Ltd.
KW - Continuous performance task
KW - Hypofrontality
KW - Schizophrenia
KW - Steady state visually evoked potential
KW - Vigilance
UR - http://www.scopus.com/inward/record.url?scp=0034192209&partnerID=8YFLogxK
U2 - 10.1016/S1388-2457(99)00324-7
DO - 10.1016/S1388-2457(99)00324-7
M3 - Article
C2 - 10802456
AN - SCOPUS:0034192209
SN - 1388-2457
VL - 111
SP - 850
EP - 857
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
IS - 5
ER -