Serial dependence in the perception of attractiveness

Abstract

The perception of attractiveness is essential for choices of food, object, and mate preference. Like perception of other visual features, perception of attractiveness is stable despite constant changes of image properties due to factors like occlusion, visual noise, and eye movements. Recent results demonstrate that perception of low-level stimulus features and even more complex attributes like human identity are biased towards recent percepts. This effect is often called serial dependence. Some recent studies have suggested that serial dependence also exists for perceived facial attractiveness, though there is also concern that the reported effects are due to response bias. Here we used an attractiveness-rating task to test the existence of serial dependence in perceived facial attractiveness. Our results demonstrate that perceived face attractiveness was pulled by the attractiveness level of facial images encountered up to 6 s prior. This effect was not due to response bias and did not rely on the previous motor response. This perceptual pull increased as the difference in attractiveness between previous and current stimuli increased. Our results reconcile previously conflicting findings and extend previous work, demonstrating that sequential dependence in perception operates across different levels of visual analysis, even at the highest levels of perceptual interpretation.

Figure 1

Cartoons of four examples of the experiment stimuli. (A–B) Two different face images of one identity; (C–D) two different face images of another identity. The stimuli of the experiment were 5,000 color photographs of 50 different identities. The four images in this figure are cartoon versions for reproduction.

Figure 2

Illustration of experiment design and the terminology. Forty face images were rated in a random order in the first run and then the same 40 images were rated in another random order in the second run. In the analysis of the responses given in one run, the responses given in the other run can serve as independent references. For example, an independent reference for the response to the image displayed in the ith trial in the first run (resp_i) can be the response to the same image in the second run, which is defined as the independent response of the ith trial (idp_i). Note that this independent response of the ith trial was not necessarily given at the ith trial in the second run. Also, independent responses of trials i and i − 1 were not necessarily given in successive trials. The corresponding mathematical symbols used in the models are noted in parentheses.

Figure 3

(A) Residuals of Model 1 plotted against the difference between the independent responses of previous and current trials. The blue line shows the linear regression and the gray shading represents the 95% confidence interval of the linear fitting. (B) Partial view of (A) with magnified y-axis for illustration of the confidence interval. The positive slope in the fit indicates that the response on the current trial was pulled toward the attractiveness of the previously seen face.

Figure 4

(A) Serial-dependence effect size as a function of the temporal interval between the stimulus displays of previous and current trials. (B) Serial dependence computed for stimuli presented one to five trials back from the present trial. Error bars in both panels represent the 95% bootstrapped confidence interval.