Dual functional hemispheric asymmetry in visual perception: Effects of ocular dominance and postexposural processes

Abstract

The authors investigated laterality differences in visual perception by assessing the effects of the directional post-exposure scanning movements associated with reading habits, the visual half-field (VHF) in which stimuli were presented, and eye dominance on an immediate recall task. Forty Chinese bilingual subjects (20 right-eye dominant and 20 left-eye dominant) were tested for their recall of forms, Chinese words and English words. The stimuli were projected tachistoscopically in the left and/or right VHFs under conditions of simulataneous and successive presentation. The results demonstrated a right field superiority for verbal stimuli under both conditions and a left field superiority for nonverbal stimuli when presented successively. Right-eyed subjects were better in processing verbal materials and left-eyed subjects were better in the perception and recall of nonverbal materials. The study supported the validity of the psychophysiological model of asymmetrical cerebral functioning and demonstrated the importance of reading habits and eye dominance. The findings were interpreted as preliminary support for Piaget's postulated relationship between perceptual and organic development.