DIFFERENTIAL HEMISPHERIC LATERALIZATION OF PRIMARY AND SOCIAL EMOTIONS - IMPLICATIONS FOR DEVELOPING A COMPREHENSIVE NEUROLOGY FOR EMOTIONS, REPRESSION, AND THE SUBCONSCIOUS

Eleven patients underwent injection of amobarbital into their right an d left internal carotid arteries (Wada test) to determine propositiona l language dominance as part of a standard clinical evaluation when co nsidering ablative neurosurgery for control of epileptic seizures. Dur ing the fight-sided injection, patients were asked to recall verbally an emotional life experience that had been identified before the Wada test as part of a research project to assess affective prosody. To our astonishment, most of the patients dramatically altered their recall of the affective but not the factual content of the life event. This p aper recounts these serindipitous and unexpected observations and, in conjunction with a literature review, develops the formative concept t hat social emotions are modulated by the left hemisphere, whereas prim ary emotions are modulated by the right hemisphere, a hypothesis that readily encompasses two divergent but commonly held views concerning t he lateralization of emotions in the brain-all (primary) emotions are modulated by the right hemisphere versus positive emotions are modulat ed by the left hemisphere while negative emotions are modulated by the right. A comprehensive neurology of emotions relevant to understandin g psychiatric behaviors is then synthesized, which also accounts for t he psychological constructs of repression and the subconscious.