Normal p50 gating in unmedicated schizophrenia outpatients.
OBJECTIVE
The hypothesis of a sensory gating defect in schizophrenia has been supported by studies demonstrating deficient auditory P50 gating in patients. P50 gating is the relative attenuation of P50 amplitude in the auditory evoked potential following the second auditory stimulus of a stimulus pair.


METHODS
Auditory evoked potentials of 12 unmedicated male patients with schizophrenia and 24 healthy men were recorded during three runs of 40 click pairs. Three alternative waveform-processing strategies were used to analyze the data.


RESULTS
Regardless of strategy used, the differences between subject groups regarding P50 amplitude and gating were nonsignificant.


CONCLUSIONS
The P50 gating in the patient group was normal. The results do not support the concept of the P50 gating defect as a general trait marker of schizophrenia.
Arnfred
Sidse M
SM
Department of Psychiatry, Bispebjerg Hospital, University Hospital of Copenhagen, Bispebjerg Bakke 23, DK-2400 København NV, Denmark. s.arnfred@tdcadsl.dk
Chen
Andrew C N
AC
Glenthøj
Birte Y
BY
Hemmingsen
Ralf P
RP
D000161:Acoustic Stimulation; D000328:Adult; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D008297:Male; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology