Windey, B. 1 , Gevers, W. 2 & Cleeremans, A. 1
1 CO3. ULB. Brussels, Belgium
2 Unescog. ULB. Brussels, Belgium
This study aims to shed light on an ongoing debate in the visual awareness literature: is the transition from unconscious to conscious processing graded or dichotomous? The Recurrent Processing Hypothesis assumes a graded transition (longer presentation durations lead to gradually enhanced visibility). The Global Workspace Theory assumes an all-or-none transition (stimuli remain unconscious until the duration is sufficient to generate sudden clear experiences). Here we intend to unify the two theories and their supporting evidence, by taking the so far overlooked factor of the “level of processing” of stimuli into account. Participants performed a task on low-level stimuli (categorizing colored patches as red or blue) or on high-level stimuli (categorizing numbers as smaller or larger than 5). Presentation duration of the postmasked stimuli was varied parametrically. As expected, the psychophysical detection curve for the low-level stimuli showed a graded pattern, whereas the curve for the high-level stimuli showed a dichotomous pattern. In the next experiment we present the same stimuli (colored numbers) in both conditions, to match both conditions more closely. We hypothesize that for low-level stimuli, access to a more graded local workspace is sufficient to become conscious, whereas high-level stimuli require access to an all-or-none global workspace.