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Stimulus Intensity Expectation and Visual Evoked Brain Potentials
Author(s) -
Shucard David Wm.,
Shucard Janet L.
Publication year - 1978
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.1469-8986.1978.tb03103.x
Subject(s) - stimulus (psychology) , psychology , audiology , amplitude , waveform , evoked potential , second order stimulus , visual evoked potentials , visual perception , perception , neuroscience , optics , physics , cognitive psychology , medicine , quantum mechanics , voltage
In a sample of 32 adult subjects, we examined the relationship between amplitude measures of the visual evoked potential (VEP) and a subject's expectation that a stimulus would be either brighter or dimmer than the others in a series. It was found that when subjects expected a bright light flash, the VEP waveform changed in the direction associated with a stimulus intensity increase even though no actual intensity change occurred. Conversely, when subjects expected a dim light flash, the VEP waveform changed in the direction associated with a stimulus intensity decrease even though no actual intensity change occurred. The amplitude changes to the expected stimulus intensities occurred in specific VEP peaks and were related to the position of the stimulus in the sequence.