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Biomedical subjects

M W Shefsky

Publications and source records attributed to M W Shefsky.

3 recordsLinked to original sources

Visual laterality effects: reexamination.

Subjects were asked to indicate, by a simple motor response, the presence or absence of a word (signal) in unilaterally presented five-letter words and nonwords (noise). Both vertical and horizontal orientation of stimuli were employed. Detection accuracy (d') did not differ between visual hemifields and was greater for horizontal than for vertical orientation. Decision making was more conservative for left-hemifield presentation and more conservative for vertical orientation. Models for perceptual asymmetry based on structural differences between cerebral hemispheres are weakened by the results.

Adult

Hemispheric asymmetry: a signal detection analysis.

Subjects were asked to indicate, by a simple motor response, the presence or absence of a predesignated target letter in unilaterally presented consonant trigrams. Perceptual sensitivity (d') was signficantly greater in the right visual hemifield and did not depend upon hand of response. Reaction times were slightly higher in the left hemifield and for the left hand. Response bias (beta) did not differ between hemifields. Models of perceptual asymmetry as a consequence of information loss transcallosally are weakened by the results.

Dominance, Cerebral