Datensatz

Zusammenfassung

The visual instability that results from viewing ambiguous or conflicting patterns is
thought to reflect dynamic processes that are critical for perceptual organization during
normal vision. We have recently discovered a method to prolong states of perceptual
dominance up to two orders of magnitude by periodically switching off and on the inducing
bistable pattern. In the current study we used this paradigm to temporally interleave
the presentation of pairs of ambiguous stimuli at the same location in visual space.
Bistable patterns including rotating three-dimensional objects, depth reversals, and binocular
rivalry, were shown alternately with appropriate blanking periods to prolong
phases of perceptual dominance. We were interested under what conditions the time
courses of two parallel bistable visual processes would be independent.
We found that for certain pairs of ambiguous stimuli, such as 3-D balls rotating around
orthogonal axes, the time course of perceptual alternation was largely parallel and independent.
However, for other patterns, e.g. those differing only in color, speed, size, or
position, the two stimuli were synchronized in their reversals.
These results suggest that for a given visual location, perceptual organization can be
biased for multiple different bistable stimuli simultaneously, but that the independence
between pairs of stimuli depends upon their similarity. We will discuss the results with
respect to the critical stimulus dimensions that determine whether or not interference
occurs.