Abstract
The human visual system can construct the 3D perspective of an object based on simple 2D contours. This process is presumably an essential part of the visuomotor control that allows for appropriate interaction with object. Here we investigated whether the construction of 3D objects from 2D line drawings could occur in the absence of awareness. Observers adapted to a Necker cube rendered unambiguous with occlusion cue, and then were presented with an ambiguous Necker cube and reported the perceived perspective of the test cube. In each trial, the unambiguous adapting cube was presented monocularly for 2 seconds either alone (visible) or with Continuous Flash Suppression (CFS) noise in the other eye (invisible). Nor surprisingly, the visible unambiguous Necker cube induced a clear adaptation aftereffect in that observers were about 20% more likely to perceive the test Necker cube in the opposite perspective compared to the adapting cube. This adaptation aftereffect was very robust and was observed even when the test cube was different in size from the adapting cube, presented at different retinal location, or presented in the different eye. Interestingly, a perspective adaptation aftereffect was obtained even when the adapting cube was invisible, and the aftereffect from the invisible adapter could also be observed with different relative size of the cubes, but the aftereffect disappeared when test cube was presented at a different retinal location from the adapter. In contrast to the visible adapter, an invisible adapter induced a priming effect when the test cube was presented in the opposite eye. Results from this study suggest that the visual system can construct 3D perspective in the absence of awareness of the retinal image. These results are consistent with the observations, for example in blindsight patients, that appropriate visuomotor action could be executed independent of explicit visual awareness.
Meeting abstract presented at VSS 2015