Is stimulus recognition a necessary condition for the occurrence of exposure effects?

Many theories of exposure effects involve the operation of psychological processes that depend on some form of stimulus recognition. Two experiments investigated the role of stimulus recognition in the mere exposure phenomenon. Female subjects viewed novel stimuli at various exposure frequencies, then measures of stimulul recognition and effect were obtained. In each experiment, a significant and positive relationship was found between stimulus exposure and affect, even when the effects of stimulus recognition were held constant. Thus, stimulus recognition was not a necessary condition for the occurrence of the observed exposure effects. The results suggest that the relationship between stimulus exposure and affect does not depend on the operation of higher order cognitive processes, at least to the extent that such processes are themselves dependent upon stimulus recognition.