Foster PS, Drago V, Webster DG, Harrison DW, Crucian GP, Heilman KM.
Neuropsychology, 22, 127-135
The relationships between the anterior-posterior and left-right regions of the brain have been characterized as mutually inhibitory. Whereas the left hemisphere attends to right proximal hemispace and is associated with positive emotions, the right hemisphere attends to left distal hemispace and is associated with negative emotions. Because of the excitatory and inhibitory influences between the left and right frontal and posterior regions of the brain, the expression of emotion will result in an ipsilateral attentional bias. Given these functional systems, we hypothesized that positive emotions would be associated with a bias for left distal hemispace and negative emotions would be associated with a bias for right proximal hemispace. We tested these hypotheses by having 138 undergraduate students place emotionally labeled pegs on a large board. Our results indicated that the positively labeled pegs were placed in left distal hemispace and the relative placement of negatively labeled pegs was rightward and proximally. Whereas numerous research investigations have examined how attention is biased for emotional stimuli, ours is the first investigation to provide evidence that emotions can bias attentional allocation.
Showing posts with label hemisphere. Show all posts
Showing posts with label hemisphere. Show all posts
Tuesday, January 29, 2008
Friday, October 19, 2007
ARTICLE UPDATE - Alteration of expected hemispheric asymmetries: Valence and arousal effects in neuropsychological models of emotion.
Alfano KM, Cimino CR.
Brain and Cognition, in press
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>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>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>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>LH performance. These results are analogous to the pattern of relative hemispheric activations observed for various mood states. Controlling for arousal 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.
Brain and Cognition, in press
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>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>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>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>LH performance. These results are analogous to the pattern of relative hemispheric activations observed for various mood states. Controlling for arousal 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.
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