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).”

“These are the EBA and FBA (extrastriate and fusiform body area) and OFA and FFA (occipital and fusiform face area), respectively (Puce et al., 1996, Kanwisher et al., 1997, Downing et al., 2001, Peelen and Downing 2005, Schwarzlose et al., 2005, Downing et al., 2006, Peelen et al., 2006).”

“Several lines of evidence have consistently suggested that the left inferior temporal cortex constitutes a cerebral substrate for the perception of visual words (Tarkiainen, Helenius, Hansen, Cornelissen, & Salmelin, 1999; Puce, Allison, Asgari, Gore, & McCarthy, 1996; Nobre, Allison, & McCarthy, 1994).”

“Face stimuli have consistently elicited significantly more activation in this region than other objects or scrambled face stimuli (Sergent et al., 1992; Allison et al., 1994a, b; Puce et al., 1995, 1996; Kanwisher et al., 1997).”

“…of affairs contrasts notably to the object recognition literature, where questions about possible distinct neural systems for category-specific (Puce and others 1996; McCarthy and others 1997; Haxby and others 2000; Kanwisher 2004; Downing and others 2005) or task-specific (Diamond and Carey…”

“While a considerable body of data exists on neural localization of the structures specifically devoted to orthographical analysis of real versus false fonts or non-letter strings, namely left lingual and fusiform gyri (Nobre, Allison, & McCarthy, 1994; Petersen, Fox, Posner, Mintun, & Raichle, 1988, Petersen, Fox, Sny…”

“In humans, a region of posterior fusiform gyrus (fusiform face area, FFA) responds generally and selectively to human faces in fMRI studies [3,4].”

“, 2003), which also consider other aspects of faces besides person identity (Haxby et al., 1994, 1996, 2000; Puce et al., 1996; Adolphs et al., 2000; de Gelder and Rouw, 2000; Hoffman and Haxby, 2000; Adolphs, 2002; de Gelder et al., 2003).”

“The VWFA activation is located in left extrastriate cortex (Talairach coordinates: x = −43, y = −54, z = −12), is identifiable in single subjects (Puce, Allison, Asgari, Gore, & McCarthy, 1996 ), and is sensitive to the individual's experience—Hebrew readers show greater activation of this region for Hebrew than for E…”

“For example, many fMRI and ERP studies show bilateral activation for words and for faces, albeit usually with greater activation for words on the left and faces on the right side of the brain (Sergent et al. 1992; Puce et al. 1996; Kanwisher et al. 1997; Tagamets et al. 2000; Hasson et al. 2002; Kronbichler et al. 200…”

“We found some evidence for differences in reproducibility between ROIs: between scanning sessions the PPA showed less reduction in T-value than did the FFA and OFA.”

“Another region in the inferior occipital gyrus called the IOG [Hoffman and Haxby, 2000] has been less well studied, but has been shown to respond more strongly to faces than to objects or houses in half or more of subjects scanned [Halgren et al., 1999; Haxby et al., 1999; Lerner et al., 2001; Levy et al., 2001; Puce…”

“The face specificity and location of the FFA could be demonstrated at higher spatial resolution in numerous fMRI studies (Clark et al. 1996; Puce et al. 1996; Kanwisher et al. 1997; Tong et al. 1998; Halgren et al. 1999; Hasson et al. 2001; Grill-Spector et al. 2004; Kanwisher and Yovel 2006).”

“Within this extensive network, converging evidence suggests that a subregion of the left fusiform gyrus, whose Talairach coordinates are approximately x = � 43, y = � 54, z = � 12, contributes crucially to the cerebral basis of the VWF (Cohen et al., 2000; Beauregard et al., 1997; Puce, Allison, Asgari, Gore, & McCart…”

“…sulcus (Clarkresponses to unpredictable presentations of individual novel et al. 1996, 1997; Haxby et al. 1994; Kanwisher et al. 1997;stimuli cannot be discriminated from responses to familiar McCarthy et al. 1997b; Puce et al. 1996; Sergent et al. 1992).stimuli presented in the same sequence.”

“In addition to these electrophysiological findings, f MRI has revealed more activity in the left occipito-temporal junction for letter strings relative to textures and faces ( Puce, Allison, Asgari, Gore, & McCarthy, 1996 ).”

“In this regard, it is interesting to note that one region along the fusiform gyrus that has received a great deal of attention in fMRI studies is the fusiform face area, or FFA (Kanwisher et al. 1997; Puce et al. 1996; for review, see Grill-Spector and Malach 2004).”

“…parts of visual cortex is generally consistent with previous reports that have found similar selectivity in and around the collateral sulcus (Cant et al., 2009; Cant and Goodale, 2007; Peuskens et al., 2004; Puce et al., 1996) as well as distributed through visual cortex (Beason-Held et al., 1998).”

“This increase appears at odd with their proposed human face-specificity [55] of FFA bilaterally and right LFA.”

“The involvement of the CoS in visual texture perception is in line with results demonstrating that this region responds specifically to texture patterns compared to faces and letter strings (Puce et al., 1996).”

“Con - versely , FFA activation was reduced by attention to houses when faces and houses both appeared in the stimulus ( Wojciulik et al .”

“Face identification in these general models is thought to rely on a posterior to anterior ventral-temporal axis, predominant in the right hemisphere [De Renzi et al., 1994; Kanwisher et al., 1997; McCarthy et al., 1999; Puce et al., 1996; Rossion et al., 2000], with posterior regions processing visuospatial aspects of…”

“Further, brain-imaging work from both PET and fMRI had already found strong activations when people looked at faces (Sergent et al., 1992; Haxby et al., 1994; Puce et al., 1996).”

“…cortex is essential for many aspects of visual form processing, including face, object, and word recognition (Arguin and others 1996; Puce and others 1996; Kanwisher and others 1997; Grill-Spector and others 1998; De Renzi 2000; Hasson and others 2002; James and others 2003; Farah…”

“…the presented consonant letter strings than for pseudofonts subjects were presented with a string of three kana or faces (Price et al., 1996; Puce et al., 1996; Tarkiainen letters for each trial of 4 s, and they were asked to et al., 2002), indicating that this region is selectively judge…”

“However, the left hemisphere also plays a role in face perceptual processes, and face-selective activations have been nearly as often described in the left occipito-temporal regions of the fusiform gyrus (i.e., Rossion, de Gelder, et al., 2000; Gauthier et al., 1999; Haxby et al., 1999; Halgren et al., 1998; Puce, All…”

“Fusiform activations at 150–200ms (M170) during face processing have been well established (Barbeau et al., 2008; McCarthy et al., 1997; Puce et al., 1995, 1996), even when the faces were not directly attended (Cauquil et al., 2000; Furey et al., 2006), as we also observed.”

“, 2000, 2002), but this picture changes when letters and letter strings are contrasted with more complex stimuli, like pictures of faces (Puce et al., 1996) or objects (Joseph et al.”

“…materials potentially trigger the automatic activation of a widespread neural network irrespective of the behavioural tasks engaged (Price et al., 1996), and also because the ventral visual systems including the PITC may respond to both verbal and non-verbal visual materials (Puce et al., 1996).”

“Neuropsychological patients with focal brain damage and neuroimaging studies of the undamaged brain demonstrate that recognition of particular stimulus categories, such as faces and bodies, depends on dissociable regions in occipitotemporal cortex (Puce et al., 1996; Kanwisher et al., 1997; Moscovitch et al., 1997; Ro…”

“Several of these studies focused on the fusiform face area (FFA), a region of cortex that responds much more strongly to faces than to nonface objects and is believed to be critical for face recognition (Kanwisher, McDermott, & Chun, 1997; McCarthy, Puce, Gore, & Allison, 1997; Puce, Allison, Asgari, Gore, & McCarthy,…”

“... similar breeds of dogs in the near-absence of attention? It could be argued that the results we observe here would not generalize to other natural categories since various studies have claimed that dedicated areas in the brain exist that preferentially process face stimuli, and that faces are thus of special impor…”

“VC 2008 Wiley-Liss, Inc. bodies in the previously specified FFA, but application of high-resolution functional magnetic resonance imaging (fMRI) techniques revealed a segregation of face and body selective regions [Schwarzlose et al., 2005].”

“…using contrasts of face viewing versus scrambled face viewing (Puce, Allison, Gore, & McCarthy, 1995), face viewing versus letter string viewing (Puce et al., 1996), face matching versus location matching (Haxby et al., 1994), face identification versus gender identification (Sergent, Ohta, &…”

“Affected brain systems have been posited to include: face perception, linked to the fusiform gyrus (Kanwisher et al., 1997; Puce et al., 1996); biological motion perception, linked to the superior temporal sulcus (Pelphrey et al.”

“Previous studies (Puce et al., 1996; McCarthy et al., 1997) indicate that the presence of faces would activate the FG, hence this formed a control ROI in this study.”

“This activated area overlapped with the right fusiform face area that is selectively involved in face processing (Kanwisher, McDermott, & Chun, 1997; Puce, Allison, Asgari, Gore, & McCarthy, 1996 ), and the bilateral extrastriate body area that is selectively involved in the visual processing of human bodies and faces…”

“cortex that typically shows face-specific activation in fMRI studies (Puce et al., 1996; Kanwisher et al., 1997; McCarthy et al., 1997; Haxby et al., 1999).”

“Neural Activation During Face Processing Evidence from brain imaging studies indicates that the posterior lateral fusiform area activates more to faces and face-like stimuli than to other categories of stimuli (e.g., Downing et al. 2006; Puce et al. 1996).”

“Words, pronounceable pseudowords, and letters activate parts of the left fusiform gyrus and collateral sulcus (Puce et al., 1996; Cohen et al., 2000; Polk and Farah, 2002; Polk et al., 2002; Baker et al., 2007).”

“As for the dorsal path, the LP is often reported in the same studies that report LOT activation for letters [22,41,42,43,44,45], thus implying a role in letter processing for both regions.”

“biological motion in the superior temporal sulcus (Puce et al. 1996; Grossman and Blake 2002; Beauchamp et al. 2003; Pitcher et al. 2011), 2) objects versus scrambled objects to identify”

“The lateral part of the fusiform gyrus, the so-called FFA, is preferentially activated by faces, and a large volume of electrophysiological (Allison et al, 1999 ; McCarthy et al, 1999 ; Puce et al, 1999 ; Allison, Ginter, et al, 1994 ; Allison, McCarthy, et al, 1994 ), and imaging (Kanwisher et al, 1997 ; McCarthy et…”

“Along similar lines, in the functional neuroimaging literature, a number of studies have reported “activation dissociations” between written words/letter strings and/or visual objects and faces (Gauthier et al., 2000; Hasson et al., 2002; Puce et al., 1996; Bar et al., 2001; Malach et al., 2002).”

“Further, this is consistent with the hemispheric differences observed in neuroimaging [Puce et al., 1996; Kanwisher et al., 1997] and electrophysiological [Watanabe et al.”

“Prior studies suggested that letter identification in sighted people is a special case of object recognition [Flowers et al., 2004; Garrett et al., 2000; Polk et al., 2002; Puce et al., 1996; Tagamets et al., 2000].”

“Neuroimaging studies in humans reveal homologous regions in the temporal cortex that are activated by these stimuli (Puce et al., 1996; Kanwisher et al., 1997).”

“These results are also in agreement with evidence of orthographic processing in extra-striate regions by fMRI and PET methods (Petersen et al., 1990; Puce et al., 1996; Pugh et al., 1996; Pugh et al., 1997).”

“Haxby, Hoffman, & Gobbini, 2000; Kanwisher, McDermott, & Chun, 1997; Puce, Allison, Asgari, Gore, & McCarthy, 1996 ), neuroanatomical investigations on animals (e.g.”

“The FFA has typically been defined as the area in the fusiform gyrus that responds more to faces than to comparison stimuli, such as houses or other objects (Kanwisher et al., 1997; Puce et al., 1995).”

“These structures include: (1) the lateral fusiform gyrus (FFG), or “fusiform face area,” located in the ventral occipitotemporal cortex of humans and thought to be important for rapid face recognition (eg, Kanwisher, McDermott, & Chun, 1997 ; Puce, Allison, Asgari, Gore, & McCarthy, 1996 ).”

“Although none of these studies, nor recent confirmatory studies using fMRI (Puce et al., 1995, 1996), actually prove that the right fusiform gyrus is involved in face processing per se (for example, similar signal changes might well have been observed with any class of three-dimensional object),…”