Dominique Lamy, Tel Aviv University
November 30 2015, 11h Salle de réunion du LPP, H432, 4ème étage, Centre Biomédical des Saints Pères 45 rue des Sts Pères, 75006 Paris
Revisiting visual unconscious processing
Delineating the limits of unconscious processing in order to understand the function of consciousness in visual processing has been a central goal for research. I will first examine what measure is best suited to index conscious processing - and absence thereof. Recent research suggests that subjective measures can be as sensitive as objective forced-choice performance, leading to the conclusion that these direct measures both tap conscious perception. A notable exception is blindsight patients, who report no subjective awareness of stimuli that they can localize or discriminate way above chance level. However, it is important to reflect on what above-chance performance actually means: simply that some information – any information - guides the observers’ guesses. I will suggest that this information is not necessarily visual and present experiments testing this conceptual framework in healthy participants. Then, I will address the question of whether conscious and unconscious processes lie on a continuum or reflect the operation of separate mechanisms. To do so (a) I will present a paradigm that departs from the gold standard adopted in unconscious processing research and allows comparing conscious and unconscious processing rather than simply detecting the presence of unconscious processing and (b) I will rely on effects of prior expectations to show that conscious perception and indirect effects of visual stimulation on motor action can be dissociated.