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Cells sensitive to faces and other body parts.

  • Cells responding to visual stimuli are progressively further removed from response to retinal stimuliation, going through to higher-numbered visual areas

  • In V3 some cells are “gaze-locked”: they response to a particular position of retinal stimuli only when the animal fixates a particular position.
    V6 is map of position in space with some gaze locked neurons, and others which respond to a particular position in space no matter where the monkey fixates. (Zeki, 1993, p 340)

  • Higher order cells responding more closely to objects rather than features, are found in the temporal lobe. Gross and co- workers in the 80’s reported cells which responded to a monkey’s paw, and faces in superior temporal sulcus.
    Some cells in pre-motor cortex respond to visual stimuli only if they are in the vicinity of the animal’s own arm, and other visually responsive cells in the temporal lobe seem to respond to anything except the sight of the animal’s own arm (Hietanen and Perrett, 1993)

  • There are patches of cells in the temporal lobe which are sensitive to particular views of particular faces (of other animals or experimenters: Perrett et al 1985; Harries and Perrett, 1991)

  • In parts of the parietal lobe there are neurons which respond selectively when the animal observes particular kinds of grasping movement of a hand, and these seem to be related to “mirror neurons” in the premotor cortex which response both when the monkey observes another animal or the experimenter gripping an object and when it grips the object itself (Rizzolatti et at 1996; Gallese et al 1996)

  • Imaging studies of human subjects suggest that the localization of these functions in the human brain is predictable from that found in monkeys (Fadiga et al, 1995; Grafton et al 1996)

  • Cells in macaque temporal cortex recognize direction of motion and view of the body, and a proportion of these continue to be selective when the information is limited to the movement of light patches attached to the points of limb articulation (Oram and Perrett, 1994). Even more closely related to precursors for imitation of object manipulation, there are cells in parietal cortex which response to objects according type of manipulation (Murata et al. 1996). These provide input to cells in premotor cortex of macaques, which discharge either when the animal performs a grasping action itself (even in the dark) or when it observes the human experimenter, or another monkey perform the action (Rizzolatti et al. 1996). It has not unreasonably been proposed that these cells may be part of an observation/execution matching system (Gallese et al. 1996) which shows some degree of comparability between macaques and humans (Fadiga et al. 1995; Grafton et al. 1996).

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