Laterality and visual masking: Interhemispheric communication and the locus of perceptual asymmetries for words.

Abstract

Experiments 1 and 2 measured the critical interstimulus interval at which a word presented to the right or left field escaped a trailing noise or pattern mask. Perceptual asymmetries were absent in the noise mask condition. A right field advantage of about 4 ms that did not vary with predictability of target location was found in the pattern mask condition. Experiment 3 showed that pattern masking leads to a right field advantage even when accuracy is well below asymptote. Hemispheric differences for word identification are either absent or inconsistent at early, peripheral stages of processing, but emerge strongly at higher-order central processing stages in humans. The estimate of interhemispheric transmission times from these masking studies are on the order of 4 ms.