Abstract
Manipulable objects could be processed by dorsal stream under continuous flash suppression (CFS) while nonmanipulable objects could not (Fang & He, 2005). Previous research showed that category congruent primes under CFS facilitated the categorization of manipulable objects, but not that of nonmanipulable objects, which inferred that category information of manipulable objects could be unconsciously processed by dorsal stream (Almeida, Mahon, Nakayama, & Caramazza, 2008). But recent research found that elongated-shaped primes, regardless of their categories, facilitated the categorization of manipulable objects, which suggested that it was elongated-shape, not category information, that processed by dorsal stream in unconscious condition, and it might be explained that elongated-shaped stimuli were always graspable, which was sufficient to affect the categorization (Almeida et al., 2014). However, it was unknown whether manipulability based on the affordance of elongated shape could be unconsciously processed in dorsal stream. In the present study, a breaking-CFS experiment was conducted to explore whether grasping could affect the unconscious processing of manipulable objects. Object images with contrast ramped up gradually from 0 to full contrast within 1 second were presented in nondominant eye, whereas CFS stimuli were presented in dominant eye. Participants were asked to judge the object location by left hand as quickly and accurately as possible, with their right hand grasping a model in a dark box. The volume of model might be congruent or incongruent with the actual volume of the objects in images. The result showed that the suppression time of the object images was significantly shorter when participants grasped the models whose volume were congruent with the suppressed objects than those whose volume were incongruent with the objects. It suggested that grasping modulation of manipulable object processing occurred in the absence of visual awareness, and it might be manipulability, not elongated shape, that could be processed by dorsal stream in unconscious condition.
Meeting abstract presented at VSS 2018