[The functional asymmetry of the emotions]

A considerable body of neuropsychological and psychophysiological evidence suggests that the left hemisphere of the human brain is related to positive emotions, whereas the right hemisphere is related to negative emotions. R. Davidson and W. Heller (1993) suggested that it is determined by the ratio between the activities of the left and right regions of the frontal cortex. Comparison of these premises with those proposed by need-informational theory of emotions suggests that the right frontal cortex preferentially deals with pragmatic information (earlier experience stored in memory) required for satisfaction of the actual need, whereas the left frontal cortex processes most recent and currently available information. Unit activity of the prefrontal cortex was investigated in rats during stimulation of the emotionally positive (lateral hypothalamic area) and negative (dorsomedial tegmentum) structures. The asymmetry was revealed in neuronal responses: the prevalence of the left hemisphere during emotionally positive stimulation and of the right hemisphere during negative stimulation. Further research should provide more knowledge on the features of information processing by the left and right frontal cortical regions in humans and animals and elucidate the nature of interaction of these areas with need--and information-related cortico-limbic structures of the brain.