Can you HAND-le these emotions? An investigation on hemispheric dominance with exposure to visual stimuli.
Sciences and Mathematics, College of
Psychological Science, Department of
BURS Faculty Advisor
Hemispheric dominance, like those related to handedness, has implications in clinical settings. For example, it predicts language lateralization, with right-handers showing left-hemispheric dominance and left-handers presenting more variable designations. Such lateralization extends to affective mechanisms. Emotional processing is widespread in the brain, but higher-order judgements are frequently localized in prefrontal cortices, as addressed by three theories. The Right Hemisphere hypothesis localizes most emotional processing on the right hemisphere (Borod, 1998). The Valence-Specific hypothesis involves judgment of emotional qualities (left hemisphere= positive; right hemisphere=negative) (Palomero-Gallagher, 2022). The Approach-Withdrawal hypothesis explains motivational behavior (left hemisphere= approach; right hemisphere= withdrawal) (Davidson, 1990). The current study aims to understand emotional hemispheric lateralization, in conjunction with handedness. We hypothesize right-handers showing higher activity in the left hemisphere when viewing positively-valenced and approachable faces. Connected to fNIRs (8x8 montage, bilateral prefrontal), 37 participants (age= 20.3[1.7]; 23F, 31 dextral) completed a novel forced-choice task, Facial Emotional Valence Assessment (FEVA). Fifteen separate emotional blocks were presented, with three blocks for each emotion type (happy, sad, anger, disgust and fear). After preprocessing (Homer3), data was topographically analyzed to extract hemispheric dominance for each block. Results on right-handers demonstrate higher oxy-hemoglobin in the right hemisphere when viewing all emotional faces. However, left-handers demonstrate right dominance for sad and disgust, left dominance for fear and anger, and bilateral activity for happy faces. Overall, such work contributes to the affective neuroscience literature and guides targeted interventions for clinical groups experiencing emotional deficits.
Howard, Keirsten; Gowri Srinivasan, Prathyusha; Tadros, Youstina; Potts, Hannah; and Scherling, Carole PhD, "Can you HAND-le these emotions? An investigation on hemispheric dominance with exposure to visual stimuli." (2023). Belmont University Research Symposium (BURS). 288.