Patterns of music agnosia associated with middle cerebral artery infarcts

Abstract

The objective of the study is to evaluate if the rupture of an aneurysm located on the middle cerebral artery (MCA) results in disorders of music recognition. To this aim, 20 patients having undergone brain surgery for the clipping of a unilateral left (LBS), right (RBS) or bilateral (BBS) aneurysm(s) of the MCA and 20 neurologically intact control subjects (NC) were evaluated with a series of tests assessing most of the abilities involved in music recognition. In general, the study shows that a ruptured aneurysm on the MCA that is repaired by brain surgery is very likely to produce deficits in the auditory processing of music. The incidence of such a deficit was not only very high but also selective. The results show that the LBS group was more impaired than the NC group in all three tasks involving musical long-term memory. The study also uncovered two new cases of apperceptive agnosia for music. These two patients (N.R. and R.C.) were diagnosed as such because both exhibit a clear deficit in each of the three music memory tasks and both are impaired in all discrimination tests involving musical perception. Interestingly, the lesions overlap in the right superior temporal lobe and in the right insula, making the two new cases very similar to an earlier case report. Altogether, the results are also consistent with the view that apperceptive agnosia results from damage to right hemispheric structures while associative agnosia results from damage to the left hemisphere.

How does the brain process music?

“…4,5 Adjacent and surrounding areas in the anterior temporal lobe and insula are involved in identification of nonverbal sounds including familiar music. 11,12 The lateral temporal and parietal lobes link auditory information with information derived from other sensory modalities (especially vision). Circuits in the parietal and frontal lobes mediate working memory for music and other sounds and behavioural responses to sound.…”

“…Deficits in the recognition of familiar tunes may occur with damage involving the anterior STG and insula in either cerebral hemisphere and similar areas are activated in healthy subjects. 11,12 Emotion. Partly in parallel to the extensive cortical network for the perceptual and cognitive processing of sound lies the phylogenetically much older circuit that mediates emotional responses.…”

A mismatch negativity study of local–global auditory processing

“…1). Consequently, researchers employing interval-contour melodic variations have recently downplayed the mapping between melodic structure and local-global structure (e.g., Ayotte et al, 2000;Fujioka et al, 2004). This might indicate recognition of the failure for the interval-contour stimuli to adequately capture local-global perceptual structure.…”

Auditory attention to frequency and time: an analogy to visual local–global stimuli

“…For the different items, one tone of the melody is changed, either such that both interval and contour have been changed, or such that the interval on the scale has been disrupted but the contour preserved. These stimuli have been used extensively in behavioral studies (Peretz, 1987;Peretz & Morais, 1980, neuropsychological studies (Ayotte, Peretz, Rousseau, Bard, & Bojanowski, 2000;Liégeois-Chauvel, Peretz, Baba¿, Laguitton, & Chauvel, 1998;Peretz, 1990;Zatorre, 1985), and studies employing event-related potentials (Fujioka, Trainor, Ross, Kakigi, & Pantev, 2004;Schiavetto, Cortese, & Alain, 1999;Trainor, McDonald, & Alain, 2002), with at best mixed results regarding the proposed hemispheric asymmetry.…”