Abstract
Visual features can be integrated across retinotopic locations. For example, when a Vernier is followed by a sequence of flanking lines on either side, a percept of two diverging motion streams is elicited. Even though the central Vernier is unconscious due to metacontrast masking, its offset is visible at the following elements. If an offset is introduced to one of the flanking lines, the two offsets integrate (Otto et al., 2006). Here, by varying the number of flanking lines and the position of the flank offset, we show that this integration lasts up to 450ms. Furthermore, this process is mandatory, i.e, observers are not able to consciously access the individual lines and change their decision. These results suggest that the contents of consciousness can be modulated by an unconscious memory-process wherein information is integrated for up to 450ms. This mandatory and unconscious process is not sluggish, but very precise. By using parallel streams, we show that even for spatially very close stimuli the offsets do not spill over. Offsets integrate only when presented in the same stream. Hence, these results suggest that non-retinotopic feature integration is a very precise mechanism, and that the streams create a spatio-temporal window of unconscious, mandatory integration that lasts up to 450ms.
Meeting abstract presented at VSS 2017