Discrimination without Awareness?

Abstract

The fate of the unattended message in dichotic listening experiments is a much disputed issue. Moray (1969) proposes that there is no processing of the unattended message, whereas Norman (1969) has suggested that it is analyzed to the level of meaning. In order to test these alternative hypotheses an experiment was performed in which galvanic skin responses (GSR) were conditioned to a word (CS) by pairing it with shock. The word was then included in passages of prose presented to subjects as the attended and unattended messages in a dichotic listening task. GSR's were obtained to the occurrence of CS in the unattended message and also to words acoustically similar to CS and to synonyms of CS. The probability of obtaining a GSR to the occurrence of an accoustically similar word was increased by placing that word in a context appropriate to CS. These results suggest that the unattended message can be processed to a level at which semantic information is extracted without the subject's reported awareness.