The Japanese journal of neuropsychology

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ArticleTitle	Emotion and memory -Four studies of the emotional memory in Alzheimer's disease-
Language	J
AuthorList	Hiroaki Kazui^{1), 2)}
Affiliation	¹⁾Department of Clinical Neurosciences, Hyogo Institute for Aging Brain and Cognitive Disorders ²⁾Psychiatry and Behavioral Science, Osaka University Graduate School of Medicine
Publication	Japanese Journal of Neuropsychology: 18 (3), 150-156, 2002
Received
Accepted
Abstract	Emotional memory is a special category of memory for events arousing strong emotions. We conducted four studies of the emotional memory in patients with Alzheimer's disease (AD). In the first study, we compared memories of experiencing the Kobe earthquake with those of a magnetic resonance imaging (MRI) examination given after the earthquake in individuals with AD who experienced the earthquake at home in the greater Kobe area. The purpose of the study was to investigate the effects of emotional involvement on memory retention in patients with AD. The intensity of emotional impact is apparently stronger in the earthquake than in the MRI examination. Subjects retained memories of the earthquake far more frequently than memories of the MRI examinations, indicating the emotional impact reinforced memory retention of the event. In the second study, we investigated the relationship between memories of events surrounding the Kobe earthquake and amygdalar and hippocampal volumes in patients with AD who encountered the earthquake. Irrespective of generalized brain atrophy and cognitive impairments, emotional memory was correlated more with normalized amygdalar volume than with normalized hippocampal volume. The results indicated that impairment of emotional event memory in patients with AD was related to intensity of amygdalar damage and provided evidence of the amygdalar involvement in emotional memory in humans. Because the design of the first study involved a naturalistic approach, it was difficult or impossible to control for some factors of the target events, other than emotional impact of the event, which could have influenced memory retention. In the third study, we reevaluated the finding of an enhancement of memory for emotional material in mild AD with the strictly controlled emotional memory paradigm. The results provided further evidence that emotional arousal enhanced memory in patients with AD. In addition, the extent of the improvement of memory by emotion was similar in the subjects with mild AD and in the healthy subjects. In the last study, the specific effects of visual and verbal memory on the ability of emotional arousal to enhance declarative memory were examined in patients with AD. In AD, the memory enhancement by emotion was significantly correlated with visual memory but not with verbal memory, regardless of age, sex, educational attainment, and severity of dementia, suggesting a close association between memory enhancement by emotion and visual memory. In addition, we discussed the mechanism of emotional memory and clinical implications provided from studies of emotional memory.
Keywords	emotion, memory, amygdala, Alzheimer's disease