Mere exposure effect(s) in the context of explicit memory search.

Prior stimulus exposure often increases later ratings of positive affect (e.g., pleasantness ratings). This phenomenon - the mere exposure effect (MEE) - appears robust following subliminal and incidental exposures. However, its expression in the context of explicit memory judgment remains unclear. In four studies, memory and pleasantness ratings were combined to investigate how memory conclusions (e.g., "studied" or "unstudied") might moderate exposure effects. Experiment 1 examined basic recognition, Experiment 2 manipulated incentives for recognition decisions, and Experiments 3 and 4 examined source memory and paired-associate recall respectively. In general, items endorsed as recognized, attributed to the queried source, or accompanied by successful recall of a paired associate (i.e., confirmations) were rated as more pleasant than baseline norms. As important, items endorsed as unstudied, rejected as originating from a queried source, or failing to yield successful recall of a paired associated were rated as less pleasant than baseline norms. This suggests that it is the outcome of memory search that alters pleasantness ratings in the context of retrieval demands, and we discuss how this confirmation of search (COS) hypothesis accounts for current and prior findings.