Abstract
Many approaches have been used to support the claim that visual discriminations are still possible in absence of visual awareness, notably concerning nonconscious processing of facial expressions. Interpretation of masking studies is often complicated by the fact that performance and target visibility tend to co vary. Metacontrast masking permits to create experimental conditions in which subjective visual awareness and the objectively measured visual discrimination ability are manipulated separately1. We used a metacontrast masking paradigm to investigate perception of bodily expressions without visual awareness. Pictures of bodies expressing anger and happy were used as targets. The masks consisted of compounds of body parts (trunk, six arms and six legs in various positions) and they were presented at 12 different SOA's varying from −50 to 133 milliseconds. Participants were instructed to categorize the expression of the target body and subsequently to indicate whether they had seen the body or not. The results show that affective stimulus perception without visual awareness is clearly observed for angry body stimuli and not for happy stimuli and that the effect is modulated by observer characteristics (when excluding so called overachievers2).
1. Lau, H.C., & Passingham, R.E (2006). Relative blindsight in normal observers and the neural correlate of visual consciousness. Proc Natl Acad Sci U S A, 103, 18763-18768.
2. Pessoa, L., Japee, S., Sturman, D., ∓ Ungerleider, L.G (2006). Target visibility and visual awareness modulate amygdala responses to fearful faces. Cereb Cortex, 16, 366-375.