Observation of a reversible, medication-induced change in pitch perception.

This paper reports a study of an absolute pitch possessor who, upon administration of the psychoactive drug Tegratol (carbamazepine), experienced a significant change in her pitch perception. The subject's performance both in producing, as well as in identifying, random-frequency tones was measured, covering the period of administration of the drug, as well as control periods before and after. The main effect of the drug was a downward shift of the perceived pitch as compared to the two control periods. The magnitude of the shift was observed to increase with increasing fundamental frequency of the stimulus; the average shift was about one semitone. Detailed results on the frequency dependence and time dependence of the pitch shifts are presented. This may be the first documented report of a significant, reversible change of pitch perception caused by a medication.