Face inversion reveals holistic processing of peripheral faces

Abstract

Face perception is accomplished by face-selective neural processes, involving holistic processing that enables highly efficient integration of facial features into a whole-face representation. It has been shown that in face-selective regions of the ventral temporal cortex (VTC), neural resources involved in holistic processing are primarily dedicated to the central portion of the visual field. These findings raise the intriguing possibility that holistic processing might be the privilege of centrally presented faces and could be strongly diminished in the case of peripheral faces. We addressed this question using the face inversion effect (FIE), a well-established marker of holistic face processing. The behavioral results revealed impaired identity discrimination performance for inverted peripheral faces scaled according to the V1 magnification factor, compared to upright presented faces. The size of peripheral FIE was comparable to that found for centrally displayed faces. Face inversion affected the early ERP responses to faces in two time intervals. The earliest FIE was most pronounced in the time window between 130 and 140 msec following stimulus presentation, for both centrally and peripherally displayed faces and in the latter case, it was present only over the contralateral hemisphere. The timing of the next component FIE corresponded closely with the temporal interval of the N170 ERP component and showed strong right hemisphere (RH) lateralization, both when faces were displayed in the left or right visual field (RVF). Furthermore, we also showed that centrally presented face masks impaired peripheral face identity discrimination performance, but did not reduce the magnitude of the FIE. These findings revealed robust behavioral and neural inversion effects for peripheral faces and thus suggest that faces are processed holistically throughout the visual field.

Does right hemisphere superiority sufficiently explain the left visual field advantage in face recognition?

“…We interpret this as indicative of equivalent processing of spatial relations for RVF and LVF half-faces viewed in isolation. Previous studies using a face inversion manipulation have reported that holistic processing of spatial relations can occur for peripherally viewed faces in both hemifields (Kovács, Knakker, Hermann, Kovács, & Vidnyánszky, 2017), but is greater in the LVF than the RVF (Cattaneo et al, 2014;Hillger & Koenig, 1991;Leehey, Carey, Diamond, & Cahn, 1978). Our finding of equivalent processing for RVF and LVF halves of centrally viewed faces when viewed alone suggests that greater face-processing resources are available for centrally viewed faces as compared to peripherally viewed faces.…”

The Flashed Face Distortion Effect Does Not Depend on Face-Specific Mechanisms

“…By manipulating face orientation in our first task, we thus hoped to examine the extent to which the FFDE is selective for faces, as opposed to being a reflection of more general properties of visual processing in the periphery. The lack of an effect of inversion in our task (despite evidence that other inversion effects are not limited to central vision 32,33 ) suggests that face-specific mechanisms at best make a relatively small contribution to the FFDE (see our discussion following Experiment 1 regarding the interpretation of Bayes Factors between 1–3). We therefore conjecture that the FFDE may depend primarily on general properties of object processing in the visual periphery, or lower-level mechanisms that apply to an even broader class of stimuli.…”

Different hemispheric specialization for face/word recognition: A high‐density ERP study with hemifield visual stimulation

“…Therefore, the present result is interesting in that only the right FFA showed the largest response to faces irrespective of the visual field. Similarly, Kovacs, Knakker, Hermann, Kovacs, and Vidnyanszky (2017) reported that the face‐N170 showed right hemispheric specialization without contralateral predominance, regardless of RVH or LVH. This is consistent with the right hemisphere being specialized for face recognition (Davies‐Thompson et al., 2016; Kanwisher, McDermott, et al, 1997).…”