Two core motivational systems have been conceptualized as underlying emotion and behavior. The approach system drives the organism toward stimuli or events in the environment, and the avoidance system instead deters the organism away from these stimuli or events. This approach—avoidance dichotomy has been central to theories of emotion. Advances in neuroscience complementing well-designed behavioral experiments have begun to elucidate the neural mechanisms underlying approach—avoidance motivation, suggesting that these two systems exist in parallel and are lateralized in the brain. This (...) review explores the notion of approach—avoidance and the cerebral lateralization of these motivational tendencies. (shrink)

Several visual and emotional processes reflect similar underlying patterns of cortical activation. Characteristic individual perceptual style was measured by lateral attentional errors in a standard visual line-bisecting task. The direction of error indicates a predominance of activation in the contralateral prefrontal cortex. Individual differences in mood were measured by the self-endorsement of emotional adjectives. A total of 27 right-handed adults responded to the trait version of the Positive and Negative Affect Schedule (PANAS). As predicted, rightward errors in visual line bisecting (...) correlated positively and significantly with the Positive Affect subscale. The scale adjectives determined and strong had significant correlations with the visual bisecting measure. The negative affect subscale was correlated with neither the line bisecting measure nor the positive subscale. An extension from trait to state measures tested the self-description of current affect using related synonyms and antonyms in a subset of 22 of the participants. Active, dominant, mighty, powerful, and strong were significantly associated with rightward bisecting errors, whereas passive and cooperative were correlated with errors in the opposite direction. The results were incompatible with the valence model (positive-negative), direction model (approach-withdrawal), and movement model (approach-resistance) of the lateral prefrontal substrate of emotion. The action tendency model (active approach-passive yielding) was supported. (shrink)