In the Lancet for November 13, 1999, is a letter from neurologists in Japan, describing the strange case of a woman aged 88 who experienced musical hallucinations of abrupt onset. Her cognitive faculties were otherwise not impaired. She heard various melodies with which she was familiar, but heard no spoken voices. Detailed examinations showed that her hearing acuity, brain computed tomography and magnetic resonance imaging findings were normal, and there was no evidence of any psychiatric or neurological disease. The patient had received little musical training during her life. Magnetometer tests indicated that during periods when she heard the music there were specific functional changes in her right auditory associative cortex, and blood flow in the right superior temporal and right inferior frontal gyri increased.
It has been found that verbal stimuli activate predominantly the left auditory cortex in the brain, whereas non-verbal stimuli such as musical notes result in a predominantly right-sided activation. From observations of the patient concerned, the focus of musical hallucinations appears to be the right auditory associative cortex.