par Windey, Bert ;Cleeremans, Axel
Référence ASSC (17: 12-15/7/2013: San Diego, USA)
Publication Non publié, 2013-07-15
Poster de conférence
Résumé : The nature of our visual experience of the world has been examined thoroughly in both philosophy and cognitive psychology, but a number of issues remain the object of hot debates. One such pending issue is whether our visual experience is graded or dichotomous. Considerable evidence has been collected for both views. In a series of experiments, we tested whether the level of processing of the presented stimuli can account for seemingly contradictory results. Participants expressed either low-level judgments (color naming) or high-level judgments (number or word categorization) on the very same stimuli. We analysed both mean performance and mean subjective visibility ratings for stimulus durations ranging from 10 to 80 ms. Earlier work has shown that psychophysical curves exhibit a significantly more dichotomous transition in the high-level task than in the low-level task. The present research expands upon this work. Using different subjective measures, we examined whether participants use more intermediate scale points in the low-level condition than in the high-level condition, which would suggest a more graded perception for low-level stimuli and tasks. Results using confidence ratings were found to confirm this prediction. Altogether we propose that whether visual experience is graded or dichotomous depends on the level of processing of the stimuli during task execution. This has important implications for theories of consciousness that make claims about the graded vs. dichotomous nature of visual experience, such as global workspace theory.