Hemispheric differences in affective response: Effects of mere exposure

This study investigated hemispheric differences in the "mere exposure" effect, the increase in liking that is typically found with repeated presentations of stimuli. Hemispheric dominance models predict that one hemisphere mediates the relationship between exposure and liking regardless of stimulus type, whereas perceptual fluency models predict that liking will be better for stimuli projected to the hemisphere with greater proficiency for processing that stimulus type. Stimuli were presented for 50 ms to the left (LVF), right (RVF), or central (CVF) visual field. The number of stimulus presentations was systematically varied from 1 to 8 exposures. Stimuli were faces in Experiment 1, and words and non-words in Experiment 2. Results revealed that when subsequently rated in free vision, faces were liked better if they had previously been presented to the LVF/right hemisphere, whereas words were liked better if they had previously been presented to the RVF/left hemisphere. Results are interpreted as supporting perceptual fluency models of the mere exposure effect, and arguing against the hypothesis that the mere exposure effect is mediated by the affective response of a single hemisphere.