Abstract
Despite the noisy and ever-changing visual world, our visual experience appears remarkably stable over time. Recent research indicates that our percepts, such as orientation, are biased towards previous percepts (Fisher & Whitney, 2014). Based on this and other recent results, serial dependence was proposed as a mechanism to facilitate perceptual stability, compensating for variability in visual input. Whereas serial dependence was shown to occur with a variety of stimuli, the underlying mechanism(s) and determining factors are still unknown. Here, we investigated individual differences in serial dependence on a larger scale, with a sample size of 125 naive participants. Observers were presented with a sequence of oriented Gabors and were asked to adjust the orientation of a bar to match each Gabor's orientation. Positive serial dependence had an average half-peak strength of 1.6°. Serial dependence, in these participants, remained robust across demographic differences (e.g. gender and age) and levels of task difficulty. Interestingly, serial dependence was stronger for low contrast Gabors compared to medium and high contrast Gabors and serial dependence was more consistent for low contrast Gabors (100% of participants, 4°) versus high Contrast (78% of participants, 1.8°). Serial dependence was also stronger for oblique angles compared to cardinal angles (4° vs. 0.5°) and present in a larger number of participants (89% vs 62%). Taken together, our results show serial dependence is a stable and consistent perceptual effect across observers, although it can be modulated by multiple factors. These results further reinforce the idea of serial dependence as a mechanism to promote perceptual stability in everyday life.
Meeting abstract presented at VSS 2018