Differential Sensitivity of Human Visual Cortex to Faces, Letterstrings, and Textures: A Functional Magnetic Resonance Imaging Study

“Twelve normal right-handed subjects (Edinburgh Handedness Inventory range 70 –100) (Oldfield, 1970) without a previous neurological or psychiatric history participated in this study.”

“There are advocates of a unitary system (Damasio et al., 1982; Critchley, 1986; Biederman, 1987), two subsystems dealing with faces and words (Farah, 1990), two subsystems dealing with living and nonliving objects (Sheridan and Humphreys, 1993; Newcombe et al.”

“These results are consistent with the neuropsychology literature (for review, see Rhodes, 1993) demonstrating a right hemisphere advantage for face recognition and with previous PET (Horwitz et al., 1992; Haxby et al., 1995) and scalp-recorded evoked potential (Bentin et al., 1996) studies.”

“Semantic processing of auditorily presented words also activated regions of the temporal lobe distant from ventral cortex (Petersen et al., 1988; Wise et al., 1991; Démonet et al., 1992).”

“Malach et al. (1995) compared the fMRI activation produced by objects (including faces) with the activation produced by textures.”

“It is activated by colors, shapes, and scrambled faces (Corbetta et al., 1991; Clark et al., 1995; Puce et al., 1995a), but not specifically by faces (Table 1) (see also Clark et al., 1995; Puce et al., 1995a).”

“Little activation and no letterstring-specific activation of left superior and middle temporal cortex was seen, regions previously activated in PET studies involving phonological processing or word reading (Petersen et al., 1989; Démonet et al., 1992; Howard et al., 1992; Price et al., 1994).”

“Little activation and no letterstring-specific activation of left superior and middle temporal cortex was seen, regions previously activated in PET studies involving phonological processing or word reading (Petersen et al., 1989; Démonet et al., 1992; Howard et al., 1992; Price et al., 1994).”

“Previous PET studies have consistently shown face activation of this region (Sergent et al., 1992; Haxby et al., 1994, 1995).”

“Regions engaged in processing of color and form (for review, see Maunsell and Newsome, 1987), faces (Gross, 1992; Perrett et al., 1992), facial expression (for review, see Rolls, 1992), motion (for review, see Albright, 1993), and “biological motion” (Oram and Perrett, 1994) have been described.”

“Semantic processing of auditorily presented words also activated regions of the temporal lobe distant from ventral cortex (Petersen et al., 1988; Wise et al., 1991; Démonet et al., 1992).”

“The region activated by unpronounceable nonwords here partially overlapped, but was inferior and lateral to a medial extrastriate region activated by words and pronounceable pseudowords (but not by false fonts or unpronounceable nonwords ) in the study of Petersen et al. (1990).”

“, concrete nouns or unpronounceable nonwords), whereas longer-latency potentials recorded from anterior regions of the inferior temporal lobe were highly sensitive to word type (Nobre et al., 1994).”

“The t-maps computed for each stimulus alternation order were further analyzed using two methods: (1) A " split-t " map (Puce et al., 1995b) was generated for each subject in which only those voxels whose associated t values exceeded Ϯ 1.5 for both stimulus alternation orders were retained.”

“Little activation and no letterstring-specific activation of left superior and middle temporal cortex was seen, regions previously activated in PET studies involving phonological processing or word reading (Petersen et al., 1989; Démonet et al., 1992; Howard et al., 1992; Price et al., 1994).”

“We predicted from electrophysiological studies (Allison et al., 1994a; Nobre et al., 1994) that activation of ventral surface cortex by letterstrings would be medial to that for faces.”

“…with the present study, the lesion evidence suggests that prosopagnosia (for review, see De Renzi et al., 1994) and pure alexia (for review, see Damasio and Damasio, 1983) are forms of visual agnosia preferentially involving lesions of the right and left occipitotemporal regions, respectively.”

“This processing occurs within two separate but interconnected pathways, a ventral pathway dealing with object recognition, and a dorsal pathway dealing with motion, spatial relationships, and visually guided movement (Ungerleider and Mishkin, 1982; Goodale and Milner, 1992; Ungerleider, 1995) (however, see Merigan and…”

“The collateral sulcus contains portions of areas V2, ventral V3 (VP), and V4 (Clarke and Miklossy, 1990; Clarke et al., 1995; Shipp et al., 1995).”

“, 1992), facial expression (for review, see Rolls, 1992), motion (for review, see Albright, 1993), and “biological motion” (Oram and Perrett, 1994) have been described.”

“Consistent with the present study, the lesion evidence suggests that prosopagnosia (for review, see De Renzi et al., 1994) and pure alexia (for review, see Damasio and Damasio, 1983) are forms of visual agnosia preferentially involving lesions of the right and left occipitotemporal regions,…”

“Intracranial recordings also have revealed a left dominant asymmetry (our unpublished observations), and evoked potential studies have shown that a letterstring N180 is larger over the left than the right temporal scalp (Nobre and McCarthy, 1994), complementary to the distribution obtained by Bentin et al.”

“The t-maps computed for each stimulus alternation order were further analyzed using two methods: (1) A " split-t " map (Puce et al., 1995b) was generated for each subject in which only those voxels whose associated t values exceeded Ϯ 1.5 for both stimulus alternation orders were retained.”

“Previous PET studies have consistently shown face activation of this region (Sergent et al., 1992; Haxby et al., 1994, 1995).”

“Previous PET studies have consistently shown face activation of this region (Sergent et al., 1992; Haxby et al., 1994, 1995).”

“Previous PET studies have consistently shown face activation of this region (Sergent et al., 1992; Haxby et al., 1994, 1995).”

“These results are consistent with the neuropsychology literature (for review, see Rhodes, 1993) demonstrating a right hemisphere advantage for face recognition and with previous PET (Horwitz et al., 1992; Haxby et al., 1995) and scalp-recorded evoked potential (Bentin et al., 1996) studies.”

“Visual cortex located posterio-medial to the face, letterstring, and numberstring areas was preferentially activated by colored checkerboards (Allison et al., 1993).”

“The frequency analysis has been described in detail (McCarthy et al., 1995; Puce et al., 1995a).”

“It has been argued that faces are an important category of objects for which rapid recognition requires specialized processing (Young and Bruce, 1991; Newcombe et al., 1994).”

“We suspect that our face activation is somewhat more lateralized to the right hemisphere than that seen in Courtney et al. (1997) and Puce et al. (1995, 1996), because our use of objects as comparison stimuli allowed us to effectively subtract out the contribution of general object processing to…”

“For example, Puce et al. (1996) found bilateral fusiform gyrus activation for faces, but with more extensive activation in the right hemisphere.”

“…in patients with the syndrome of prosopagnosia indicate that the homologous areas specialized for face and object identification are located predominantly within the mid-portion of the fusiform gyrus (BA 37 and BA 20) (Damasio, 1985; Sergent et al., 1992; Allison et al., 1994; Puce et al., 1996).”