Affective discrimination of stimuli that are not recognized: effects of shadowing, masking, and cerebral laterality.

Based on his finding that subjects can show an affective preference to previously seen stimuli that they fail to recognize, Zajonc (1980) claimed that affective processing operates separately from cognitive processing. Over four experiments, we replicated and extended the finding that mere exposure to a briefly presented stimulus can increase positive affect through familiarity without enhancing the recognition of that stimulus. Among our findings, lateralized presentation of the irregular polygon stimuli showed that affect judgments were best for stimuli presented in the right visual field (left hemisphere), whereas recognition judgments were best for stimuli presented in the left visual field (right hemisphere). These effects were found only when the study stimuli were shown for 2 msec and were unmasked or for 5 msec and were pattern masked; when the stimuli were shown for 5 msec and were energy masked, target selection by affect or recognition was not greater than chance. These data, along with results from contingency probability analyses, indicate that affect and recognition judgments are different. Rather than viewing the difference between affect and recognition in terms of different features that might reside in the stimulus, the difference in judgments may reflect the manner in which a stimulus representation has been accessed. When viewed in terms of different retrieval processes that access different information, target selection by affect in the absence of recognition can be interpreted in terms of existing models of recognition memory.