Amusia

Amusia

Amusia is a loss of the ability to appreciate music despite normal intelligence, memory, and language function. Subtypes have been described: receptive or sensory (loss of the ability to appreciate music) and expressive or motor (e.g., loss of ability to sing, whistle). Clearly a premorbid appreciation of music is a sine qua non for the diagnosis (particularly of the former), and most reported cases of amusia have occurred in trained musicians. Others have estimated that amusia affects up to 4% of the population (presumably expressive). Tests for the evaluation of amusia have been described.

Amusia may occur in the context of more widespread cognitive dysfunction, such as aphasia and agnosia. It has been found in association with pure word deafness, presumably as part of a global auditory agnosia. Isolated amusia has been reported in the context of focal cerebral atrophy affecting the nondominant temporal lobe. However, functional studies have failed to show strong hemispheric specificity for music perception, but suggest a cross-hemispheric distributed neural substrate. An impairment of pitch processing with preserved awareness of musical rhythm changes has been described in amusics.

References
Confavreux C, Croisile B, Garassus P, Aimard G, Trillet M. Progressive amusia and aprosody. Archives of Neurology 1992; 49: 971-976
Hyde KL, Peretz I. Brains that are out of tune but in time.
Psychological Science 2004; 15: 356-360
Schuppert M, Münte TF, Wieringa BM, Altenmüller E. Receptive amusia: evidence for cross-hemispheric neural networks underlying music processing strategies. Brain 2000; 123: 546-559
Wertheim N. The amusias. In: Vinken PJ, Bruyn GW (eds.). Handbookof clinical neurology, Vol. 4: Disorders of speech, perception, and symbolic behaviour. Amsterdam: North-Holland Publishing, 1969: 195-206

Cross References

Agnosia; Auditory agnosia; Pure word deafness