Abstract
Previous research has investigated the extent to which visual images of objects that are not consciously perceived are processed. To this end, Bar and Beiderman (1998), using a subliminal priming paradigm found that sub-threshold presentations of single objects do indeed affect performance on subsequent tasks. We asked if two sub-threshold objects would both affect future performance, a question we think has never been answered. We created a paradigm in which two black and white line drawings representing familiar objects and subtending approximately 3.5 degrees, positioned 3.5 degrees to the left and right of fixation, were presented for 14 ms and pattern masked. Subjects were then presented with two test items which they had to identify as either the same or different from one another. One of the previously presented primes was always used as a test item. Forty subjects were tested and each subject participated in 200 trials. We reasoned that if the subliminally exposed objects were processed outside of awareness, then subjects' responses to the same-different task would be quicker than their responses on trials in which no prime was presented. We found that this was the case; reaction times on primed trials were significantly shorter than those on trials in which subjects were not exposed to primes (same condition p = .011; different condition p = .000). We understand our results to represent the first demonstration of subliminal visual priming of more than one object.