The beat goes on. The new issue of Brain (Vol. 129, No 10) contains six papers on various neurological disorders of music processing, plus a great commentary by Oliver Sacks, “The power of music”. Since I personally work on neurobiological mechanisms underlying aesthetic preference formation, I was most intrigued by a paper by Nathalie Gosselin et al., entitled “Emotional reponses to unpleasant music correlate with damage to parahippocampal cortex”. (If you don’t have a subscription to Brain you can download the paper from the Peretz Lab homepage.) Here’s the abstract:
Music is typically a pleasurable experience. But under certain circumstances, music can also be unpleasant, for example, when a young child randomly hits piano keys. Such unpleasant musical experiences have been shown to activate a network of brain structures involved in emotion, mostly located in the medial temporal lobe: the parahippocampal gyrus, amygdala, hippocampus and temporal pole. However, the differential roles of these regions remain largely unknown. In this study, pleasant and unpleasant musicwas presented to 17 patients with variable excisions of the medial temporal lobe, as well as to 19 matched controls. The pleasant music corresponded to happy and sad selections taken from the classical instrumental repertoire; the unpleasant music was the dissonant arrangement of the same selections. Only patients with substantial resections of the left or right parahippocampal cortex (PHC) gave highly abnormal judgements to dissonant music; they rated dissonant music as slightly pleasant while controls found it unpleasant. This indifference to dissonance was correlated with the remaining volume in the PHC, but was unrelated to thevolume of the surrounding structures. The impairment was specific: the same patients judged consonant music to be pleasant, and were able to judge music as happy or sad. Furthermore, this lack of responsiveness to unpleasantness was not due to a perceptual disorder, because all patients were able to detect intentional errors in the musical excerpts. Moreover, the impairment differed from that induced by amygdala damage alone. These findings are consistent with a two-dimensional model of defensive response to aversive stimuli, in which the PHC and the amygdala subserve different roles.
It is great to see that systematic neuropsychological studies of aesthetic preference formation are starting to appear, supplementing the growing number of imaging studies. How about a book on this topic, Sacks?