Hemispheric asymmetries for the conscious and unconscious perception of emotional words

Abstract

The current research examines the interactions between hemispheric asymmetries for visual perception and emotion. In a series of four experiments, participants completed tasks measuring both conscious and unconscious perception of linguistic stimuli. In these studies, stimulus-presentation parameters (brief exposure duration vs masking) and the emotional valence of the test stimuli (negative vs positive) were manipulated in order to create studies in which the visual and emotional asymmetries were congruent (favoured the same hemispheres) or were incongruent (favoured opposing hemispheres). The results demonstrated that negative emotional stimuli led to a right-hemisphere advantage for conscious perception only when stimuli were shown for brief exposures (17 ms). Positive emotional words did not elicit hemispheric asymmetries. The results are discussed in terms of their relevance for theories of emotional lateralisation.

The research reported in this paper was supported by a Natural Sciences and Engineering Research Council (NSERC) of Canada grant to M.B.B-F., as well as an NSERC post-graduate scholarship and Ontario Graduate Scholarships to S.D.S. This paper benefited from the comments of Al Cheyne, Mike Dixon, Jim Frank, Gina Grimshaw, Mike Peters, and two anonymous reviewers. We are grateful for the research assistance of Shannon Waterfield, Crissa Guglietti, Rajwant Sandu, Sarah Lemay, Corey Birch, Nadine Laudi, Andreas Richter, Norman Farb, Melissa McFadden, and Jennifer Lepock.