Dichotic verbal transformations and evidence of separate processors for identical stimuli

Abstract

AFTER listening for several seconds to a clear recording of any word or phrase repeated over and over, a listener experiences illusory changes called “verbal transformations” (VTs), and hears a series of abrupt transitions, sometimes to new forms, sometimes back to the actual stimulus or to illusory forms reported earlier¹. Considerable phonetic distortion may take place, so that with the repeated stimulus ‘tress’ listeners can believe they are hearing clearly words as far removed as ‘purse’ or ‘florist’. The temporary receptive aphasia and perceptual reorganisation produced by VTs have provided access to mechanisms for speech processing not otherwise available for study². Previous investigations have been restricted to one repeated statement at a time; we have extended this research with VTs to investigate dichotic presentation of separate stimuli to each ear.