CAN WE LOSE MEMORY FOR MUSIC - A CASE OF MUSIC AGNOSIA IN A NONMUSICIAN

A follow-up study of a patient, C.N., with a severe auditory agnosia l imited to music is reported. After bilateral temporal lobe damage, C.N ., whose cognitive and speech functions are otherwise normal, is total ly unable to identify or to experience a sense of familiarity with mus ical excerpts that were once highly familiar to her. However, she can recognize the lyrics that usually accompany the songs. She can also id entify familiar sounds, such as animal cries. Thus, her agnosia appear s highly specific to music. The functional nature of her deficit has b een investigated through various perceptual tasks. She was initially s everely impaired in processing pitch sequential structure but has alwa ys enjoyed normal processing of temporal structure. This selective dis turbance for sequential pitch information can hardly account for her t une agnosia since processing of pitch variations has dramatically impr oved over the years. This recovery was not accompanied by any signs of improvement in music recognition, which remains extremely poor. Moreo ver, the fact that she has never been able to hum tunes from memory ar gues for a basic memory disturbance. Thus, she was tested here with a series of tests aiming at assessing her memory for familiar and unfami liar music. The results show that C.N. has now recovered most perceptu al skills and that despite a transient ability to exhibit knowledge of familiar music under restricted circumstances, she is markedly impair ed at naming a tune and at judging its familiarity, as well as at memo rizing familiar as well as novel music. This deficit was found to be n ot only modality-specific but music-specific as well. The findings sug gest the existence of a perceptual memory that is specialized for musi c and that can be selectively damaged so as to prevent most forms of r ecognition ability.