Hemispheric dominance for emotions, empathy and social behaviour: evidence from right and left handers with frontotemporal dementia.

Although evidence from primates suggests an important role for the anterior temporal cortex in social behaviour, human research has to date concentrated almost solely on the orbitofrontal cortex and amygdala. By describing four cases of the temporal variant of frontotemporal dementia we show how this degenerative condition provides an excellent model for investigating the role of the anterior temporal lobe, especially the right, in emotions, empathy and social behaviour. Assessments of semantic memory, processing of emotional facial expression and emotional prosody were made, empathy was measured, and facial expressions of emotion were coded. Of the two right handers described, one subject with predominantly left temporal lobe atrophy had severe semantic impairment but normal performance on all emotional tasks. In contrast, the subject with right temporal lobe atrophy showed severely impaired recognition of emotion from faces and voices that was not due to semantic or perceptual difficulties. Empathy was lost, interpersonal skills were severely affected and facial expression of emotion was characterized by a fixed expression that was unresponsive to situations. Additionally, two left handers with right temporal lobe atrophy are described. One demonstrated the same pattern of hemispheric lateralization as the right handers and had emotional impairment. The other left hander showed the opposite pattern of deficits, suggesting a novel presentation of anomalous dominance with reversed hemispheric specialization of semantic memory and emotional processing.

Positive illusions about the self: short-term benefits and long-term costs.

Two studies addressed parallel questions about the correlates and consequences of self-enhancement bias. Study 1 was conducted in a laboratory context and examined self-enhancing evaluations of performance in a group-interaction task. Study 2 assessed students' illusory beliefs about their academic ability when they first entered college and then followed them longitudinally to test claims about the long-term benefits of positive illusions. Both studies showed that self-enhancement bias was related to narcissism, ego involvement, self-serving attributions, and positive affect. Study 2 found that self-enhancement was associated with decreasing levels of self-esteem and well-being as well as with increasing disengagement from the academic context. Self-enhancement did not predict higher academic performance or higher graduate rates. Thus, the findings suggest that self-enhancing beliefs may be adaptive in the short term but not in the long term.