OBSERVATION OF A REVERSIBLE, MEDICATION-INDUCED CHANGE IN PITCH PERCEPTION

This paper reports a study of an absolute pitch possessor who, upon ad ministration of the psychoactive drug Tegratol (carbamazepine), experi enced a significant change in her pitch perception. The subject's perf ormance 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 tw o control periods. The magnitude of the shift was observed to increase with increasing fundamental frequency of the stimulus; the average sh ift was about one semitone. Detailed results on the frequency dependen ce and time dependence of the pitch shifts are presented. This may be the first documented report of a significant, reversible change of pit ch perception caused by a medication.