The binocular interaction of size and orientation channels : evoked potentials and observer sensitivity

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Vernon Leo Towle (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
M. Russell Harter

Abstract: The interaction between spatial frequency and orientation feature processing was investigated in the human visual system. The psychophysical (d') and visual evoked potential (VEP) responses to test gratings flashed to one eye were investigated as a function of the nature of a continuously presented suppressing grating viewed either ipsiocularly or contraocularly. The test and suppressing gratings were varied both in bar width (9’ vs. 36') and orientation (vertical vs. horizontal). The specificity of the suppression of the monocular VEPs depended on the latency measured. Early latencies (100-125 msec) were suppressed only when the flashed and continuous gratings were the same orientation. Intermediate latencies (200-250 msec) were suppressed when the gratings were the same size or orientation. Late latencies (275-380 msec) were suppressed only when the two gratings were the same size and orientation. The reduction in observer sensitivity (d1) paralleled the changes found in the late VEP measures. These effects were evident under both the intraocular and interocular suppressing conditions.

Additional Information

Language: English
Date: 1978
Visual evoked response
Visual pathways

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