Attention-related evoked potential correlates of precortical gating in the human visual system

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
J. Michael Harding (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Robert G. Eason

Abstract: The precortical gating hypothesis was tested by having subjects selectively attend to points in space under conditions wherein the saliency (size) of the evoking stimulus and motivation level of subjects were manipulated in an attempt to further elucidate relative contributions of retinal and neural components to visually evoked responses (VERs) occurring within the 40-70, 70-130, and 40-130 msec latency intervals poststimulus. A large, relatively salient stimulus was expected to elicit relatively more retinal than neural contributions in canthally recorded VERs. A small, relatively nonsalient stimulus was expected to elicit relatively more neural than retinal contributions in both canthally and frontally recorded VERs. All VERs recorded from frontal scalp were expected to reflect more neural than retinal contributions regardless of the size of the evoking stimulus. Attention-related enhancement of the b-wave of the ERG was expected to be revealed in only the canthal VERs for the large stimulus. The attention effect was expected to be revealed as enhanced negativity over most, if not all, of the 40-130 msec latency interval for canthal recordings evoked by the small stimulus, and frontal VERs evoked by both the large and small stimuli. Any effect of motivation was expected to be manifested as increased VER amplitude in a late component having a peak latency of about 180 msec.

Additional Information

Language: English
Date: 1987
Visual evoked response $x Research
Vision $x Research

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