Abstract
To perceive moving objects, the visual system must integrate form and motion information across space and time. Form and motion perception have historically been considered independent processes, but research repeatedly demonstrates that these processes interact in many complex ways. Spatiotemporal form integration (SFI) describes the process by which the visual system is able to integrate shape information over space and time to form percepts of stationary and moving objects. Illusory figures revealed by sequentially presented inducers are an excellent example of this integration process. It remains unknown, however, under what precise temporal and rotational constraints SFI can support static and moving figures. Here, we use adaptive staircase procedures to compare perception of SFI completed figures to standard Kanizsa figures using a wide range of timing parameters. Results indicate that under the wide range of conditions tested, participants show similar discrimination ability for spatiotemporally completed figures compared to standard Kanizsa figures. Additionally, participants made directional judgments on rotating SFI illusory squares and demonstrate that SFI supports moving illusory square percepts up to a maximum angular displacement of 6º - 7º between successive inducers. We conclude that the visual system can retain and update local and global form information over space and time periods exceeding the upper limits of iconic memory leading to percepts of stationary, as well as moving objects. This integration process is likely embodied within visual areas KO, LOC and hMT+ (McCarthy, Kohler, Tse & Caplovitz, VSS 2012). Importantly, these percepts are as robust as percepts of other forms of illusory figures.
Meeting abstract presented at VSS 2013