Visual cells in the temporal cortex sensitive to face view and gaze direction

Abstract

The direction of eye gaze and orientation of the face towards or away from another are important social signals for man and for macaque monkey. We have studied the effects of these signals in a region of the macaque temporal cortex where cells have been found to be responsive to the sight of faces. Of cells selectively responsive to the sight of the face or head but not to other objects (182 cells) 63% were sensitive to the orientation of the head. Different views of the head (full face, profile, back or top of the head, face rotated by 45° up to the ceiling or down to the floor) maximally activated different classes of cell. All classes of cell, however, remained active as the preferred view was rotated isomorphically or was changed in size or distance. Isomorphic rotation by 90–180° increased cell response latencies by 10–60 ms. Sensitivity to gaze direction was found for 64% of the cells tested that were tuned to head orientation. Eighteen cells most responsive to the full face preferred eye contact, while 18 cells tuned to the profile face preferred averted gaze. Sensitivity to gaze was thus compatible with, but could be independent of, sensitivity to head orientation. Results suggest that the recognition of one type of object may proceed via the independent high level analysis of several restricted views of the object (viewer-centred descriptions).

Robust representations for face recognition: The power of averages

“…However, evidence from a range of sources suggests that effects of view dependence need not necessarily arise from a generalisable ("rotatable") representation. Instead, a small number of canonical views (for example full face, three quarter and profile) can be used to generalize to other intermediate views without significant decrement in recognition performance (see e.g., Hill, Schyns & Akamatsu, 1997;Perrett et al, 1985Perrett et al, , 1998Logothetis, Pauls & Poggio, 1995). This position is consistent with the averaging proposal outlined here.…”

Species sensitivity of early face and eye processing

“…They are what define a face for animals yet their presence in upright faces contributes to the response differences between human and animal faces. We have tried to explain the various results of this study in the context of a recent neural model of early face processing in which the role of eyes is central (Itier et al, 2007;Itier and Batty, 2009). This model, which is based on monkey cell recordings (Perrett et al, 1982;Perrett et al, 1985) and human intracranial data McCarthy et al, 1999;Puce et al, 1999), assumes that eye and face selective neurons co-exist in the human brain and that their differential response patterns to various face stimuli can account for the N170 modulations. According to single unit recordings, face-selective cells respond to the face configuration and can also respond to isolated eyes presented outside the face context (Perrett et al, 1982, 1984, Perrett et al, 1998.…”

Coordinate transformations in object recognition.

“…Many laboratories have observed neurons in the inferotemporal (IT) cortex with highly selective responses for particular patterns and objects (for a review, see Farah, 2000, p. 89). Single-cell studies suggest that the responses of the majority of shape-selective cells in IT are orientation dependent, for faces and body parts (Hasselmo, Rolls, Baylis, & Nalwa, 1989;Perrett et al, 1985), and for objects (Logothetis, Pauls, & Poggio, 1995). The typical finding is that cells have a bell-shaped tuning curve, that is, they discharge maximally to one view of an object, and their response declines gradually as the object is rotated away from this preferred view.…”