In Search of an Integrative Method to Study Unconscious Processing: An Application of Bayesian and General Recognition Theory Models to the Processing of Hierarchical Patterns in the Absence of Awareness

<p>The dissociation between conscious and unconscious perception is one of the most<br>relevant issues in the study of human cognition. While there is evidence suggesting<br>that some stimuli might be unconsciously processed up to its meaning (e.g., highlevel<br>stimulus processing), some authors claim that most results on the processing<br>of subliminal stimuli can be explained by a mixture of methodological artefacts and<br>questionable assumptions about what can be considered non-conscious. Particularly,<br>one of the most controversial topics involves the method by which the awareness of the<br>stimuli is assessed. To address this question, we introduced an integrative approach to<br>assess the extent to which masked hierarchical stimuli (i.e., global shapes composed<br>of local elements) can be processed in the absence of awareness. We combined a<br>priming task where participants had to report global or local shapes, with the use of<br>subjective and objective awareness measures collected either in a separate block<br>(offline), or trial-by-trial during the main task (online). The unconscious processing<br>of the masked primes was then evaluated through two different novel model-based<br>methods: a Bayesian and a General Recognition Theory modeling approach. Despite<br>the high correlation between awareness measures, our results show that the use of<br>alternative approaches based on different theoretical assumptions leads to diverging<br>conclusions about the extent of the unconscious processing of the masked primes.</p>