Abstract: PURPOSE: Perceiving biological motion is a special kind of visual cognitive ability, and people can evaluate the emotions of other individuals by their body movements. However, movements often do not occur in isolation; the visual system needs to continuously process the biological motion information that enters the visual field sequentially, and the evaluation of action emotions may be influenced by past action information. The present study aimed to clarify (1) how past experiences have altered current biological motion emotion perception, and (2) what factors have influenced this alteration.
METHODS: 40 participants rated the point-light walker animation sequence continuously for emotion. The rating error and the difference from past ratings were calculated for each evaluation, and the derivative of the Gaussian function was fitted to obtain the amplitude of the effect of past evaluations on the current. Meanwhile, the autism spectrum quotient, empathy quotient, and vividness of movement imagery were measured for all participants using self-report questionnaires, then the correlations between the three and the amplitude of effects were examined.
RESULTS: (1) The curve fitting results indicate that current biological motion emotion evaluations systematically deviate from past evaluations and exhibit repulsive serial bias, and (2) the p-values and Bayes factors of the correlation analysis together indicate that the amplitude of the bias significantly related to third-person movement imagery vividness, but not to autism spectrum quotients or empathy quotients.
CONCLUSIONS: This study shows that there is a systematic serial repulsion effect for biological motion emotion perception, but that it belongs to general visual or movement perception processes, rather than social cognitive processes. This result enriches the theory of biological motion perception and provides a possible explanation for real-life action emotion recognition errors.

Key words: biological motion, social cognition, movement perception