Post-stroke acquired amusia: A comparison between right- and left-brain hemispheric damages

Although extensive research has been published about the emotional consequences of stroke, most studies have focused on emotional words, speech prosody, voices, or facial expressions. The emotional processing of musical excerpts following stroke has been relatively unexplored.

The present study was conducted to investigate the effects of chronic stroke on the recognition of basic emotions in music.

Seventy persons, including 25 normal controls (NC), 25 persons with right brain damage (RBD) from stroke, and 20 persons with left brain damage (LBD) from stroke between the ages of 31-71 years were studied. The Musical Emotional Bursts (MEB) test, which consists of a set of short musical pieces expressing basic emotional states (happiness, sadness, and fear) and neutrality, was used to test musical emotional perception.

Both stroke groups were significantly poorer than normal controls for the MEB total score and its subtests (p < 0.001). The RBD group was significantly less able than the LBD group to recognize sadness (p = 0.047) and neutrality (p = 0.015). Negative correlations were found between age and MEB scores for all groups, particularly the NC and RBD groups.

Our findings indicated that stroke affecting the auditory cerebrum can cause acquired amusia with greater severity in RBD than LBD. These results supported the "valence hypothesis" of right hemisphere dominance in processing negative emotions.