Hemispheric Specialization and Disengaging Attention from Affective Stimuli: Evidence for Valence-Dependent Lateralization in Emotion Regulation

The objective of this study was to determine the effect of laterality and valence on the ability to disengage attention from affective stimuli. 30 right-handed postgraduate students participated in the study. A tachistoscopic method was used, in a 2x2 within-groups factorial design, with laterality of presentation (right versus left visual field) and stimuli valence (positive versus negative) as independent variables. Time taken to disengage attention from affective word primes in milliseconds was measured as the dependent variable. Results showed that there was no main effect of either laterality or valence. However, a significant interaction effect (F(1, 29) = 4.43, p = 0.04, partial eta-squared = 0.13) was found indicating that the mean reaction time for disengagement of attention was shorter for negative stimuli presented to the right hemisphere, and for positive stimuli presented to the left hemisphere. This suggests that there is valence-dependent lateralization in the inhibition of affective information. The findings of this study have interesting implications for research on cognitive processes in emotion regulation. It is particularly relevant for research on emotion regulation especially in depression, given that depression is characterized by impaired disengagement from negative stimuli.