Holistic face perception is modulated by experience-dependent perceptual grouping

Abstract

What role do general-purpose, experience-sensitive perceptual mechanisms play in producing characteristic features of face perception? We previously demonstrated that different-colored, misaligned framing backgrounds, designed to disrupt perceptual grouping of face parts appearing upon them, disrupt holistic face perception. In the current experiments, a similar part-judgment task with composite faces was performed: face parts appeared in either misaligned, differentcolored rectangles or aligned, same-colored rectangles. To investigate whether experience can shape impacts of perceptual grouping on holistic face perception, a pre-task fostered the perception of either (a) the misaligned, differently colored rectangle frames as parts of a single, multicolored polygon or (b) the aligned, same-colored rectangle frames as a single square shape. Faces appearing in the misaligned, differently colored rectangles were processed more holistically by those in the polygon-, compared with the square-, pre-task group. Holistic effects for faces appearing in aligned, same-colored rectangles showed the opposite pattern. Experiment 2, which included a pre-task condition fostering the perception of the aligned, samecolored frames as pairs of independent rectangles, provided converging evidence that experience can modulate impacts of perceptual grouping on holistic face perception. These results are surprising given the proposed impenetrability of holistic face perception and provide insights into the elusive mechanisms underlying holistic perception.

Framing faces: Frame alignment impacts holistic face perception

“…This finding suggests that the disrupted contour that results from misaligning the top and bottom parts of composite faces can serve as an important feature contributing to the reduced holistic processing of misaligned faces. This finding is consistent with our previous demonstration that disrupting the perceptual grouping of the top and bottom face parts, in that case by presenting the top and bottom face parts on misaligned and differently colored backgrounds, impairs holistic perception (Curby et al, 2016;Curby et al, 2013). Notably, these data extend our previous findings by adopting a more direct manipulation to disrupt the perceptual grouping of the face parts, while again leaving the configuration of facial features intact.…”

“…Consistent with the suggested importance of intact perceptual grouping for holistic face perception, we have also provided evidence that manipulations that weaken the objecthood of stimuli, and thus object-based selection of the stimulus, impair indices of holistic perception of face, but not non-face, stimuli (Curby, Entenman, & Fleming, 2016;Curby, Goldstein, & Blacker, 2013). Specifically, when composite faces are presented in the context of perceptual cues that disrupt the perceptual grouping of the faces parts, namely when the parts are presented on differently colored and misaligned rectangles, holistic perception is impaired.…”

Holistic processing of static and moving faces.

“…Alternatively, the contribution of rigid motion to holistic processing may be overshadowed by more salient cues supporting holistic face processing. Rigid motion provides additional Gestalt cues for grouping facial parts together (Piepers & Robbins, 2012;Wagemans et al, 2012), which should facilitate holistic processing according to the dual-route hypothesis (Curby et al, 2016;Curby et al, 2013;Zhao et al, 2016aZhao et al, , 2016b. However, such facilitation may be less evident when holistic processing can be activated by more influential factors (e.g., those provided by normal upright faces and expertise with them), which leaves little room for facial motion to further enhance holistic processing.…”

“…Besides the two influential theories mentioned above, recent studies suggest that both object-based (i.e., bottom-up route) and experience-driven (i.e., top-down route) perceptual grouping contribute to holistic processing (Zhao, Bülthoff, & Bülthoff, 2016a, 2016b; see also Curby, Entenman, & Fleming, 2016;Curby, Goldstein, & Blacker, 2013;Zhou, Cheng, Zhang, & Wong, 2012). Consistent with this dual-route hypothesis, holistic processing of faces can be reduced or eliminated by disrupting object-based grouping of facial parts, despite humans having life-long experience in individuating faces (Curby et al, 2013;Zhao et al, 2016b).…”

“…With regard to the expertise hypothesis, if the automatic attention to multiple diagnostic facial parts drives holistic face processing (Richler, Wong, et al, 2011;Chua et al, 2015), both a top-down route (i.e., learned attention) and a bottom-up route (i.e., motion-based perceptual grouping) should be able to activate such holistic attention (Curby et al, 2013(Curby et al, , 2016Wong et al, 2009;Zhao et al, 2016a). Robust holistic processing of moving faces also suggests that expertise helps the visual system to develop integrative models for the spatiotemporal dynamics of natural facial movements, so that correlated movements of facial features (e.g., how eyes and mouth move during yawn or smiling) will be processed in a perceptually integrative way (Cook et al, 2015;Reinl & Bartels, 2014).…”