Local discriminability determines the strength of holistic processing for faces in the Fusiform Face Area (original) (raw)
Related papers
Journal of Vision, 2010
The perception and recognition of familiar faces depends critically on an analysis of the internal features of the face (eyes, nose, mouth). We therefore contrasted how information about the internal and external (hair, chin, face-outline) features of familiar and unfamiliar faces is represented in face-selective regions. There was a significant response to both the internal and external features of the face when presented in isolation. However, the response to the internal features was greater than the response to the external features. There was significant adaptation to repeated images of either the internal or external features of the face in the FFA. However, the magnitude of this adaptation was greater for the internal features of familiar faces. Next, we asked whether the internal features of the face are represented independently from the external features. There was a release from adaptation in the FFA to composite images in which the internal features were varied but the external features were unchanged, or when the internal features were unchanged but the external features varied, demonstrating a holistic response. Finally, we asked whether the holistic response to faces could be influenced by the context in which the face was presented. We found that adaptation was still evident to composite images in which the face was unchanged but body features were varied. Together, these findings show that although internal features are important in the neural representation of familiar faces, the face's internal and external features are represented holistically in face-selective regions of the human brain.
Beyond the FFA: Brain-behavior correspondences in face recognition abilities
NeuroImage, 2017
Despite the thousands of papers investigating the neural basis of face perception in both humans and nonhuman primates, very little is known about how activation within this neural architecture relates to face processing behavior. Here, we investigated individual differences in brain-behavior correspondences within both core and extended regions of the face-processing system in healthy typically developing adults. To do so, we employed a set of behavioral and neural measures to capture a multifaceted perspective on assessing these brain-behavior relations. This included quantifying face and object recognition behavior, the magnitude and size of functional activation within each region, as well as a measure of global activation across regions. We report that face, but not object, recognition behavior was associated with 1) the magnitude of face-selective activation in the left FFA1, 2) larger face-related regions in multiple bilateral face-patches in the fusiform gyri as well as the bilateral anterior temporal lobe and amygdala, and 3) more distributed global face-network activation. In contrast, face recognition behavior was not associated with any measure of objector place-selective activation. These findings suggest that superior behavior is served by engaging sufficiently large, distributed patches of neural real estate, which might reflect the integration of independent populations of neurons that enables the formation of richer representations.
The fusiform face area subserves face perception, not generic within-category identification
Nature Neuroscience, 2004
The function of the fusiform face area (FFA), a face-selective region in human extrastriate cortex, is a matter of active debate. Here we measured the correlation between FFA activity measured by functional magnetic resonance imaging (fMRI) and behavioral outcomes in perceptual tasks to determine the role of the FFA in the detection and within-category identification of faces and objects. Our data show that FFA activation is correlated on a trial-by-trial basis with both detecting the presence of faces and identifying specific faces. However, for most non-face objects (including cars seen by car experts), within-category identification performance was correlated with activation in other regions of the ventral occipitotemporal cortex, not the FFA. These results indicate that the FFA is involved in both detection and identification of faces, but that it has little involvement in within-category identification of non-face objects (including objects of expertise).
The response of face-selective cortex with single face parts and part combinations
Neuropsychologia, 2012
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.
The discriminability of local cues determines the strength of holistic face processing
Face perception is thought to result from the dynamic interplay between holistic and featural modes of processing. What determines the engagement of each mode is currently unknown. Here, we investigated whether the discriminability of local feature cues is a critical determinant of holistic/featural processing engagement. We estimated the strength of holistic processing based on observers’ failure to discriminate target features independently of the context of distracter features in a congruency paradigm. Feature discriminability was manipulated by varying the dissimilarity of target features parametrically, using morphing. We observed that the size of the congruency effect decayed monotonically as a function of the dissimilarity of the target features. In other words, the more similar the target features the stronger the holistic processing. A correlation analysis confirmed that local feature discriminability reliably predicted holistic engagement at upright orientation. In contrast, when a clear local feature difference was detected, perceptual contamination by the other surrounding features was prevented. This evidence firmly suggests that the interplay between holistic/featural processing depends on the discriminability of the signal provided at the local featural level.
Journal of Cognitive Neuroscience, 2012
The degree to which face-specific brain regions are specialized for different kinds of perceptual processing is debated. This study parametrically varied demands on featural, first-order configural, or second-order configural processing of faces and houses in a perceptual matching task to determine the extent to which the process of perceptual differentiation was selective for faces regardless of processing type (domain-specific account), specialized for specific types of perceptual processing regardless of category (process-specific account), engaged in category-optimized processing (i.e., configural face processing or featural house processing), or reflected generalized perceptual differentiation (i.e., differentiation that crosses category and processing type boundaries). ROIs were identified in a separate localizer run or with a similarity regressor in the face-matching runs. The predominant principle accounting for fMRI signal modulation in most regions was generalized perceptu...
The Representation of Parts and Wholes in Face-selective Cortex
Journal of Cognitive Neuroscience, 2008
Although face perception is often characterized as depending on holistic, rather than part-based, processing, there is behavioral evidence for independent representations of face parts. Recent work has linked “face-selective” regions defined with functional magnetic resonance imaging (fMRI) to holistic processing, but the response of these areas to face parts remains unclear. Here we examine part-based versus holistic processing in “face-selective” visual areas using face stimuli manipulated in binocular disparity to appear either behind or in front of a set of stripes [Nakayama, K., Shimojo, S., & Silverman, G. H. Stereoscopic depth: Its relation to image segmentation, grouping, and the recognition of occluded objects. Perception, 18, 55–68, 1989]. While the first case will be “filled in” by the visual system and perceived holistically, we demonstrate behaviorally that the latter cannot be completed amodally, and thus is perceived as parts. Using these stimuli in fMRI, we found sig...
The nature of face representations in subcortical regions
Neuropsychologia, 2014
Studies examining the neural correlates of face perception in humans have focused almost exclusively on the distributed cortical network of face-selective regions. Recently, however, investigations have also identified subcortical correlates of face perception and the question addressed here concerns the nature of these subcortical face representations. To explore this issue, we presented to participants pairs of images sequentially to the same or to different eyes. Superior performance in the former over latter condition implicates monocular, prestriate portions of the visual system. Over a series of five experiments, we manipulated both lower-level (size, location) as well as higher-level (identity) similarity across the pair of faces. A monocular advantage was observed even when the faces in a pair differed in location and in size, implicating some subcortical invariance across lower-level image properties. A monocular advantage was also observed when the faces in a pair were two different images of the same individual, indicating the engagement of subcortical representations in more abstract, higher-level aspects of face processing. We conclude that subcortical structures of the visual system are involved, perhaps interactively, in multiple aspects of face perception, and not simply in deriving initial coarse representations.
Psychology and Neuroscience, 2014
We present clinical and neurophysiological studies that show brain areas that are involved in face perception and how the right and left hemispheres perform holistic and analytic processing, depending on spatial frequency information. The hemispheric specialization of spatial frequency in face recognition is then reviewed and discussed. The limitations of previous work and suggestions for further investigations are discussed. Our conclusion is that functional sensorial asymmetries may be the basis for high-level cognitive asymmetries.