Super-Recognizers: increased sensitivity or reduced biases? Insights from serial dependence

Super-Recognizers (SRs) are people that exhibit naturally occurring superiority for processing of facial identity. Despite the increase of SR-research, the mechanism(s) underlying their exceptional abilities remain(s) unclear. Here, we investigated whether SRs’ enhanced facial identity processing could be attributed to the lack of sequential effects, such as serial dependence. In serial dependence, perception of stimulus features is assimilated toward stimuli presented in previous trials. This constant error in visual perception has been proposed as a mechanism that promotes perceptual stability in everyday life. We hypothesized that an absence of this constant source of error in SRs could account for their superior processing — potentially in a domain-general fashion. We tested SRs (n=17) identified via a recently proposed diagnostic framework (Ramon 2021) and age-matched controls (n=20) with two experiments probing serial dependence in the face and shape domains. In each experiment, observers were presented with randomly morphed face identities or shapes and were asked to adjust a face’s identity or a shape to match the stimulus they saw. We found serial dependence in controls and SRs alike, with no difference in its magnitude across groups. Interestingly, we found that serial dependence impacted SRs’ performance more than that of controls. Taken together, our results show that enhanced face identity processing skills in SRs cannot be attributed to the lack of serial dependence. Rather, serial dependence, a beneficial nested error in our visual system, may in fact further stabilize SRs’ perception and thus enhance their visual processing proficiency.