ERIC Number: EJ787449
Record Type: Journal
Publication Date: 2008-Apr
Reference Count: 0
Alteration of Expected Hemispheric Asymmetries: Valence and Arousal Effects in Neuropsychological Models of Emotion
Alfano, Keith M.; Cimino, Cynthia R.
Brain and Cognition, v66 n3 p213-220 Apr 2008
The relative advantage of the left (LH) over the right hemisphere (RH) in processing of verbal material for most individuals is well established. Nevertheless, several studies have reported the ability of positively and negatively valenced stimuli to enhance and reverse, respectively, the usual LH greater than RH asymmetry. These studies, however, have used baseline stimuli that differed from emotional stimuli on two dimensions (i.e., valence and verbal/nonverbal nature), creating interpretive difficulties as to whether differences across these conditions are due to differences in valence or the verbal/nonverbal nature of the primes used in the baseline condition. In addition, these studies, along with many others in the literature, have failed to control for potential confounding effects of arousal. Emotional stimuli vary on dimensions of valence as well as arousal and arousal may be asymmetrically presented in the brain therefore contributing to observed asymmetries. Taken together, these considerations underscore the importance of controlling for both valence as well as arousal in any investigation of the effects of emotional stimuli. The objectives of the present study were twofold: (1) to employ an appropriate baseline condition to render emotional stimuli vs. baseline stimuli comparisons meaningful and (2) to examine the extent to which emotional verbal stimuli, equated for arousal level, alter the expected LH greater than RH asymmetry in a consonant trigram task. Results demonstrated that when LH lateralized consonant trigram presentations were preceded by a positive prime, an enhancement of the expected LH greater than RH asymmetry was observed. In contrast, when trigram presentations lateralized to the RH were preceded by a negative prime, a complete reversal of the typical asymmetry was found with RH greater than LH performance. These results are analogous to the pattern of relative hemispheric activations observed for various mood states. Controlling forarousal in studies investigating asymmetries associated with emotional processing may allow more clear interpretation of data intended to test predictions of neuropsychological models of emotion. Moreover, equating stimuli on the dimension of arousal as well as valence may shed more light on conflicting findings with regard to "perception" vs. "expression" of emotion.
Descriptors: Brain Hemisphere Functions, Verbal Stimuli, Arousal Patterns, Emotional Response, Neurological Organization, Psychological Patterns, Research Methodology, Stimuli, Correlation
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Publication Type: Journal Articles; Reports - Research
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