Functional delineation of the human occipito-temporal areas related to face and scene processing: A PET study

Abstract

By measuring regional cerebral blood flow using PET, we delineated the roles of the occipito-temporal regions activated by faces and scenes. We asked right-handed normal subjects to perform three tasks using facial images as visual stimuli: in the face familiar/unfamiliar discrimination (FF) task, they discriminated the faces of their friends and associates from unfamiliar ones; in the face direction discrimination (FD) task, they discriminated the direction of each unfamiliar face; in the dot location discrimination (DL) task, they discriminated the location of a red dot on a scrambled face. The activity in each task was compared with that in the control fixation (CF) task, in which they fixated on the centre of a display without visual stimuli. The DL task activated the occipital cortices and posterior fusiform gyri bilaterally. During the FD task, the activation extended anteriorly in the right fusiform gyrus and laterally to the right inferior temporal cortex. The FF task further activated the right temporal pole. To examine whether the activation due to faces was face-specific, we used a scene familiar/unfamiliar discrimination (SF) task, in which the subjects discriminated familiar scenes from unfamiliar ones. Our results suggest that (i) the occipital cortices and posterior fusiform gyri non-selectively respond to faces, scrambled faces and scenes, and are involved mainly in the extraction of physical features of complex visual images; (ii) the right inferior temporal/fusiform gyrus responds selectively to faces but not to non-face stimuli and is involved in the visual processing related to face perception, whereas the bilateral parahippocampal gyri and parieto-occipital junctions respond selectively to scenes and are involved in processing related to scene perception; and (iii) the right temporal pole is activated during the discrimination of familiar faces and scenes from unfamiliar ones, and is probably involved in the recognition of familiar objects.

Brain and cognitive evolution: Forms of modularity and functions of mind.

“…Again, the research to date is not conclusive, but neural and perceptual systems that accommodate these and other forms of variability (e.g., dialect differences) within broader constraints are evident for speech (Doupe & Kuhl, 1999), face recognition (Nakamura et al, 2000), and gesture (McNeill, 2000). Social and cognitive research suggests plasticity in the ability to form categories related to tool use (Bloom, 1996) and social competition (Stephan, 1985), among other things.…”

“…Maguire et al (1998) also provided evidence for distinct brain systems involved in representing physical space (especially the right hippocampus and right inferior parietal cortex) and for speed of movement in this space (especially the right caudate nucleus). Nakamura et al (2000) found that regions of the left and right parietal-occipital junctions and portions of the left and right hippocampi were engaged during the processing of scenes and that these regions differed from those engaged during the processing of faces or objects. Recent demonstrations of injury-related functional dissociations between knowledge about tools (e.g., name, description of their use) and the actual use of tools suggests that distinct systems of brain regions support these distinct competencies (Hodges, Spatt, & Patterson, 1999; see also Lockman, 2000).…”

A role for left temporal pole in the retrieval of words for unique entities

“…Separation of the correlates of recognition and naming in functional imaging studies will call for designs that overcome such "automatic" processing. A possible exception in this regard is the PET study of Nakamura et al [2000]. Normal subjects performed three discrimination tasks: deciding whether a presented face is that of a personally familiar person or an unfamiliar person, deciding whether an unfamiliar face faces left or right, and deciding whether a dot superimposed on a scrambled face is on the right or left of the screen.…”

Intracranial Neurophysiological Correlates Related to the Processing of Faces

“…However, while these studies demonstrated relevant time epochs, the localization of these processes needs to be done using complementary techniques. Thus, over the last 10 to 20 years, positron emission tomography (PET) and functional MRI studies looked further into the anatomical correlates in vivo (12)(13)(14). While the underlying brain structures can now be precisely localized to within a precision of a few millimeters, no information about the temporal aspects of face processing was obtained using these techniques.…”