Unconscious semantic processing? No evidence for extracting the semantics of words during interocular suppression.

Abstract

Continuous Flash Suppression (CFS) has been used as a method to probe unconscious processing of visually suppressed stimuli. One line of research pertains to the extent to which semantic information of words is processed in the absence of awareness. Since CFS was introduced, it has been reported that neutral words break suppression faster than negative words (Yang and Yeh, 2011) (and vice versa (Sklar et al. , 2013)) and that congruent prime-target relations influence suppression time (Costello et al., 2009), but do not influence electrophysiological correlates of semantic congruency (Kang et al., 2011). In this study, we used the breaking CFS paradigm to probe whether words break suppression faster than pseudo words and whether suppression time of words is influenced by its word frequency. In all experiments, participants were instructed to indicate the location of the initially suppressed words as fast as possible upon breakthrough. In Experiment 1, we found neither evidence for word type (real vs. pseudo words) nor word frequency influencing suppression time. In Experiment 2, we scrambled pseudo words to eliminate readability of pseudo words, included an inverted condition (to control for familiarity) and used a test-retest design (to examine the consistency of suppression times). Again, no effect of word type nor word frequency was found. Moreover, no effect of inversion was found and test-retest reliability was low. A control experiment was conducted to verify that reliable data could be obtained with this CFS paradigm. The target was a white disc of which the radius was manipulated. Bigger discs broke suppression faster than smaller discs indicating a basic stimulus manipulation can indeed yield reliable results in the predicted direction. In conclusion, our results provide no evidence for the extraction of semantic information in the absence of awareness induced by interocular suppression. Meeting abstract presented at VSS 2014