Episodic and Semantic Memory for Melodies in Alzheimer's Disease

the present study addressed episodic and semantic memory for melodies in three groups of participants: 35 younger adults, 40 older adults, and 10 individuals with mild to moderate Alzheimer's disease (AD). To assess episodic memory, a study list of eight novel target melodies was presented three times, followed by a test trial in which target melodies were mixed with foil (previously unheard) melodies. Both explicit and implicit measures were obtained. Explicit memory was assessed by the accuracy of discrimination of the target melodies from the foils. Younger adults were significantly more accurate than older adults, who in turn had significantly higher scores than AD adults. Implicit memory was assessed by examining the difference in pleasantness ratings between target and foil melodies. Younger adults showed significantly greater differences in pleasantness ratings than older adults and AD adults; scores for the two latter groups did not differ. To assess semantic memory, participants were asked to identify traditional melodies within a series of traditional and novel melodies. In contrast to the episodic memory results, all three groups showed very high scores on the semantic memory task with no significant differences among groups. The results support the notion that, though other forms of musical memory may be compromised, semantic memory for melody may be preserved in normal aging and in AD.