Hemispheric interactions during a face--word Stroop-analog task.

Abstract

A Stroop-analog task with faces and words was developed to investigate intrahemispheric and interhemispheric Stroop effects (SEs). Lateralized faces and words were used in an attempt to invoke right- and left-hemispheric specialization, respectively. A prototypical male face, female face, and baby face and the corresponding words man, woman, and baby were presented as congruent or incongruent face-word pairs either to the same visual field (i.e., unilateral presentations) or to separate visual fields (i.e., bilateral presentations). Bidirectional SEs were found. Word distractors interfered with the identification of face targets, and, somewhat surprisingly, an even greater SE was obtained when words were the target and faces were ignored. Laterality effects were most pronounced for bilateral trials, whereby the SE was larger for right-hemisphere than for left-hemisphere target presentations, irrespective of type of target. This finding suggests that the left hemisphere is generally better shielded than the right from interhemispheric interference effects.