This review presents the multiple changes in emotional response and personality that occur after damage to the frontal systems, proposes operational definitions, and analyzes the published reports according to these definitions. Neurological causes of frontal lobe damage and associations of frontal dysfunction with psychiatric disturbances are summarized. It is concluded that symptoms of frontal lobe damage that have been labeled as emotional disturbances may be classified as disorders of drive or motivation, mood (subjective emotional experience), and affect (emotional expression). It is proposed that the primary change after frontal lobe pathology is a disorder of personality, a change in the stable response patterns that define an individual as a unique self. Dysfunction of personality includes cognitive abilities, with a disorder of self-reflective awareness as a key deficit.

Memory for contrived facts and the source of those facts was assessed in a group of early-stage HD patients and an age- and education-equated group of healthy control subjects. Fact recall did not differ significantly between the groups, but erroneous source attributions were more common among the HD patients. Like individuals with frontal lobe damage, HD patients have impaired memory for the source of learned information. Volume of the left caudate nucleus on MRI scans correlated with fact recall and source memory measures. These results suggest that this nucleus, or its neocortical projections, play an important role in the coding of context.