Effects of perceptual quality on hemispheric asymmetries in visible persistence.

Twp experiments were performed to investigate the effects of input stimuli's perceptual characteristics on visual hemifield asymmetries. The task used involved the temporal integration uf form: a stimulus was flashed in two incomplete but complementary flashes, which then had to be integrated over time into the complete stimulus. In this task, successful performance depends on the visible persistence of the first flash. In Experiment 1, an increase in size improved leftvisual-field-right-hemisphere (L VF -RH) performance relative to right-visual-field-Ieft-hemisphere <RVF-LID performance when the interflash interval (lFD was 60 msec. When the IFI was increased to 100 msec, a change in size had no effect. In Experiment 2, eccentricity of input was manipulated at an IFI of 80 msec, and a decrease in eccentricity was found to selectively benefit LVFRH performance. These results are interpreted in terms of Sergent's (1983) visual-spatialfrequency-based model of hemispheric lateralization.