Abstract
Perceptual bistability for stimuli like the Necker cube refers to the phenomenon of spontaneously alternating percepts while viewing the same image of a wire cube. Theories about the source of bistability can be roughly divided into two categories: 1) switching is driven by non-inferential bottom-up processes like neural fatigue; 2) switching results from a change in interpretation between two highly likely possibilities. Based on the notion that Necker cube percepts are driven by an inferential process, we hypothesize that the higher the subjective probability of a particular interpretation/orientation, the more likely the observer will report that interpretation.
The goal of our experiment was to try to bias the perception of the Necker cube's orientation by priming observers with images of unambiguously oriented objects, whose orientation corresponded to one of the two Necker cube percepts. Four different primer object images were presented for 5 seconds and varied in number, shape, size, and location, and were followed by a 10–15 second presentation of the Necker Cube. Perceptual state was recorded via button press at pseudo-random times indicated by beeps.
The primer biased the initial percept strongly toward the orientation of the cube consistent with the primer for 0.5 to 5 seconds, suggesting that perceptual switching is consistent with an inferential process. These empirical results can be interpreted in a broader context of Bayesian models of perceptual inference implemented via sampling over time.