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Occipital Alpha Activity as a Measure of Retinal Involvement in Oculomotor Control
Author(s) -
Wertheim A. H.
Publication year - 1981
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.1981.tb02476.x
Subject(s) - psychology , electroencephalography , visual feedback , stimulus (psychology) , alpha (finance) , retinal , smooth pursuit , eye movement , task (project management) , audiology , neuroscience , cognitive psychology , developmental psychology , computer vision , ophthalmology , computer science , psychometrics , medicine , construct validity , management , economics
Two experiments were carried out to test the hypothesis that a reduction of alpha energy in the occipital EEG reflects an increased dependency of oculomotor control on retinal feedback. In an ocular pursuit task subjects followed a target with their eyes. The target either moved in a repetitive, predictable pattern or varied unpredictably. Subjects were instructed to minimize eye‐tracking errors during the task, and performance feedback was provided. Oculomotor control depends on retinal feedback during on‐target performance in the unpredictable condition and during error correction in both conditions. However, subjects' on‐target performance in the predictable condition may involve some degree of automatic control, which is less dependent on retinal feedback. As expected, alpha activity was maximal in this condition. In a second experiment, alpha activity was shown not to reflect impaired information processing, since here again alpha was greatest during correct on‐target performance in the predictable condition, while reaction times (to visual stimuli presented in the moving target) were shortest in this condition and appeared to be independent of the amount of alpha during stimulus presentation.