Can We Lose Memory for Music? A Case of Music Agnosia in a Nonmusician

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Abstract
A follow-up study of a patient, C.N., with a severe auditory agnosia limited to music is reported. After bilateral temporal lobe damage, C.N., whose cognitive and speech functions are otherwise normal, is totally unable to identify or to experience a sense of familiarity with musical excerpts that were once highly familiar to her. However, she can recognize the lyrics that usually accompany the songs. She can also identify familiar sounds, such as animal cries. Thus, her agnosia appears highly specific to music. The functional nature of her deficit has been investigated through various perceptual tasks. She was initially severely impaired in processing pitch sequential structure but has always enjoyed normal processing of temporal structure. This selective disturbance for sequential pitch information can hardly account for her tune agnosia since processing of pitch variations has dramatically improved over the years. This recovery was not accompanied by any signs of improvement in music recognition, which remains extremely poor. Moreover, the fact that she has never been able to hum tunes from memory argues for a basic memory disturbance. Thus, she was tested here with a series of tests aiming at assessing her memory for familiar and unfamiliar music. The results show that C.N. has now recovered most perceptual skills and that despite a transient ability to exhibit knowledge of familiar music under restricted circumstances, she is markedly impaired at naming a tune and at judging its familiarity, as well as at memorizing familiar as well as novel music. This deficit was found to be not only modality-specific but music-specific as well. The findings suggest the existence of a perceptual memory that is specialized for music and that can be selectively damaged so as to prevent most forms of recognition ability.