Sustained effects of adaptation on the perception of familiar faces.

Abstract

Figural aftereffects are commonly believed to be transient and to fade away in the course of milliseconds. We tested face aftereffects using familiar faces and found sustained effects lasting up to 1 week. In 3 experiments, participants were first exposed to distorted pictures of famous persons and then had to select the veridical face in a 2-alternative forced choice task. Veridicality aftereffects were found in a direction opposite to the adapting distortion; these effects generalized to other pictures of the same individual and also to pictures of celebrities that had not been shown during adaptation. The findings support hierarchical theories of norm-based face coding and suggest that face adaptation effects have a representational basis. They also point toward multiple timescales in the operation of adaptation mechanisms, thereby providing a link between high-level adaptation and more general aspects of neuro-cognitive plasticity, that is, learning and memory.

Erasing the face after-effect

“…Although there are 'de-adaptation' studies that employ a strategy of using an opposing stimulus to generate after-effects to counter-act those from the first stimulus (Mesik et al, 2013), it is not known whether even brief introduction of other face stimuli in the period between the adaptor and test stimuli affects the dynamics of the face after-effect. However, notwithstanding the findings from studies of long-term after-effects (Carbon and Ditye, 2011;Carbon et al, 2007), it is plausible that the effects of adaptation to one face would be altered and possibly reduced by viewing of another face. The goal of this study was to test the hypothesis that face identity after-effects would be reduced by exposure to other face stimuli.…”

“…Recent studies also show a rapid decline in face identity after-effects in the first few seconds after adaptation (Leopold et al, 2001;Leopold et al, 2005;Rhodes et al, 2007). On the other hand, there are also reports that face distortion after-effects may persist at a modest level for 1 to 7 days (Carbon and Ditye, 2011;Carbon et al, 2007).…”

“…This function asymptotes at a value of 0, but given the evidence that there may be modest persistent aftereffects up to 7 days after adaptation (Carbon and Ditye, 2011), we modify this equation to include a small floor effect AE f : hence, AE t ¼AE max (exp(À t/τ)þAE f . Our prior studies of face identity adaptation with similar methods yielded aftereffect magnitudes ranging from 0.30 to 0.50, which can serve as an estimate range for AE max.…”

The Effect of Familiarity on Face Adaptation

“…Nevertheless, low-level adaptation effects cannot explain all of the results that were found, because there was still less adaptation to participants' own faces than to famous or unfamiliar faces. Incidentally, the fact that physically identical face images gave rise to different amounts of adaptation in experiment 2, depending on whether or not the face belonged to the participant, represents further strong evidence that face-adaptation effects involve more than just adaptation to low-level image properties (see also Carbon and Ditye 2010;Hills et al 2010;Hole 2011).…”

“…This suggests that figural aftereffects for familiar faces are significantly influenced by the identity of the face. More recently, Carbon and Ditye (2010) have shown that, whereas figural aftereffects for unfamiliar faces are generally reported to be quite shortlived, comparable aftereffects for familiar (famous) faces are much more long-lasting, being detectable as long as a week after adaptation first took place.…”