The response of face-selective cortex with single face parts and part combinations

Abstract

A critical issue in object recognition research is how the parts of an object are analyzed by the visual system and combined into a perceptual whole. However, most of the previous research has examined how changes to object parts influence recognition of the whole, rather than recognition of the parts themselves. This is particularly true of the research on face recognition, and especially with questions related to the neural substrates. Here, we investigated patterns of BOLD fMRI brain activation with internal face parts (features) presented singly and in different combinations. A preference for single features over combinations was found in the occipital face area (OFA) as well as a preference for the two-eyes combination stimulus over other combination stimulus types. The fusiform face area (FFA) and lateral occipital cortex (LO) showed no preferences among the single feature and combination stimulus types. The results are consistent with a growing view that the OFA represents processes involved in early, feature-based analysis.

Rapid gamma oscillations in the inferior occipital gyrus in response to eyes

“…The present findings are consistent with those of previous intracranial EEG studies reporting that the IOG was active in response to eyes, irrespective of gaze direction14. The present findings are also in line with those of previous neuroimaging1718, intracranial EEG19, and stimulation20 studies indicating that the IOG is involved in the processing of facial features. The results also fit with a neuroscientific model suggesting that the IOG is involved in the initial stage of processing facial features and then forwards the information to other regions, such as the STS15.…”

“…Because the IOG is the most posterior brain region that exhibits face-related activation, some researchers proposed that the IOG is involved in the initial stage of face processing, specifically, the processing of facial features1516. Consistent with this idea, several neuroimaging1718, intracranial EEG19, and stimulation20 studies confirmed that the IOG is involved in the processing of facial features. Because eyes are a facial feature, these data suggest that the IOG is involved in the initial stage of eye processing.…”

The perception of a familiar face is no more than the sum of its parts

“…First, individual facial features similar to those that we have defined in our experiments have been shown to exhibit inversion effects akin to those of complete faces (Rakover & Teucher, 1997; although see Rhodes, Brake, & Atkinson, 1993). Second, recent results have shown that a part of the brain thought to respond selectively to faces (the fusiform face area or FFA) responds similarly to face parts shown in isolation and in combination (Arcurio, Gold, & James, 2012). And third, Moscovitch, Winocur and Behrmann (1997) found that a patient suffering from a pronounced form of object agnosia (i.e., an inability to accurately recognize objects) nevertheless exhibited a normal ability to recognize whole faces as well as isolated facial features.…”

Beyond the FFA: The role of the ventral anterior temporal lobes in face processing

“…This region is primarily sensitive to low-level perceptual attributes of faces, such as spatial frequency (Eger et al, 2004), viewpoint (Ewbank & Andrews, 2008), and location (Kovács et al, 2008; Schwarzlose, Swisher, Dang, & Kanwisher, 2008). The results from several studies have suggested that the OFA is responsible for representing face parts, which are integrated into more complex representations at later processing stages, possibly by the FFA (Arcurio, Gold, & James, 2012; Liu et al, 2010; Pitcher, Charles, Devlin, Walsh, & Duchaine, 2009; Pitcher, Walsh, Yovel, & Duchaine, 2007; Schiltz et al, 2010). …”