Facilitation as well as inhibition of the blink reflex by a visual prepulse requires intact striate cortex.
OBJECTIVE
The role of visual cortex in modulation of the human eye blink reflex was assessed.


METHODS
Participants were 13 patients with unilateral striate cortex damage. Nonreflexogenic gratings were presented in their intact or blind hemifield prior to white noise or air puff blink-eliciting stimuli.


RESULTS
Inhibition of reflex amplitude was observed at asynchronies ranging from about 120 to 600ms for visible but not invisible prepulses. Facilitation by intact-hemifield gratings was observed for (1) the latency of the acoustic blink reflex, (2) the amplitude of the disynaptic cutaneous blink reflex, R1, and (3) the latency of voluntary hand-grip reactions to the reflexogenic stimuli. These facilitatory effects were absent on trials with blind-hemifield prepulses.


CONCLUSIONS
An intact V1 is required for prepulse facilitation as well as inhibition.


CONCLUSIONS
These results extend a popular model of sensorimotor gating deficits in schizophrenia.
Sonnenberg
Douglas
D
Department of Psychological Sciences, 210 McAlester Hall, University of Missouri-Columbia, Columbia, MO 65211, USA.
Johnson
Lenworth N
LN
Jurkowski
Anita
A
Hackley
Steven A
SA
D000293:Adolescent; D000328:Adult; D000368:Aged; D001767:Blinking / Q000502:physiology*; D001930:Brain Injuries / Q000503:physiopathology*; D004576:Electromyography; D004585:Electrooculography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009433:Neural Inhibition / Q000502:physiology*; D011930:Reaction Time; D014793:Visual Cortex / Q000502:physiology*