scholarly journals Perception of Face Parts and Face Configurations: An fMRI Study

2010 ◽  
Vol 22 (1) ◽  
pp. 203-211 ◽  
Author(s):  
Jia Liu ◽  
Alison Harris ◽  
Nancy Kanwisher

fMRI studies have reported three regions in human ventral visual cortex that respond selectively to faces: the occipital face area (OFA), the fusiform face area (FFA), and a face-selective region in the superior temporal sulcus (fSTS). Here, we asked whether these areas respond to two first-order aspects of the face argued to be important for face perception, face parts (eyes, nose, and mouth), and the T-shaped spatial configuration of these parts. Specifically, we measured the magnitude of response in these areas to stimuli that (i) either contained real face parts, or did not, and (ii) either had veridical face configurations, or did not. The OFA and the fSTS were sensitive only to the presence of real face parts, not to the correct configuration of those parts, whereas the FFA was sensitive to both face parts and face configuration. Further, only in the FFA was the response to configuration and part information correlated across voxels, suggesting that the FFA contains a unified representation that includes both kinds of information. In combination with prior results from fMRI, TMS, MEG, and patient studies, our data illuminate the functional division of labor in the OFA, FFA, and fSTS.

2019 ◽  
Vol 30 (2) ◽  
pp. 778-785 ◽  
Author(s):  
David Pitcher ◽  
Amy Pilkington ◽  
Lionel Rauth ◽  
Chris Baker ◽  
Dwight J Kravitz ◽  
...  

Abstract Neuroimaging studies show that ventral face-selective regions, including the fusiform face area (FFA) and occipital face area (OFA), preferentially respond to faces presented in the contralateral visual field (VF). In the current study we measured the VF response of the face-selective posterior superior temporal sulcus (pSTS). Across 3 functional magnetic resonance imaging experiments, participants viewed face videos presented in different parts of the VF. Consistent with prior results, we observed a contralateral VF bias in bilateral FFA, right OFA (rOFA), and bilateral human motion-selective area MT+. Intriguingly, this contralateral VF bias was absent in the bilateral pSTS. We then delivered transcranial magnetic stimulation (TMS) over right pSTS (rpSTS) and rOFA, while participants matched facial expressions in both hemifields. TMS delivered over the rpSTS disrupted performance in both hemifields, but TMS delivered over the rOFA disrupted performance in the contralateral hemifield only. These converging results demonstrate that the contralateral bias for faces observed in ventral face-selective areas is absent in the pSTS. This difference in VF response is consistent with face processing models proposing 2 functionally distinct pathways. It further suggests that these models should account for differences in interhemispheric connections between the face-selective areas across these 2 pathways.


2019 ◽  
Vol 31 (10) ◽  
pp. 1573-1588 ◽  
Author(s):  
Eelke de Vries ◽  
Daniel Baldauf

We recorded magnetoencephalography using a neural entrainment paradigm with compound face stimuli that allowed for entraining the processing of various parts of a face (eyes, mouth) as well as changes in facial identity. Our magnetic response image-guided magnetoencephalography analyses revealed that different subnodes of the human face processing network were entrained differentially according to their functional specialization. Whereas the occipital face area was most responsive to the rate at which face parts (e.g., the mouth) changed, and face patches in the STS were mostly entrained by rhythmic changes in the eye region, the fusiform face area was the only subregion that was strongly entrained by the rhythmic changes in facial identity. Furthermore, top–down attention to the mouth, eyes, or identity of the face selectively modulated the neural processing in the respective area (i.e., occipital face area, STS, or fusiform face area), resembling behavioral cue validity effects observed in the participants' RT and detection rate data. Our results show the attentional weighting of the visual processing of different aspects and dimensions of a single face object, at various stages of the involved visual processing hierarchy.


2016 ◽  
Author(s):  
J. Swaroop Guntupalli ◽  
Kelsey G. Wheeler ◽  
M. Ida Gobbini

AbstractNeural models of a distributed system for face perception implicate a network of regions in the ventral visual stream for recognition of identity. Here, we report an fMRI neural decoding study in humans that shows that this pathway culminates in a right inferior frontal cortex face area (rIFFA) with a representation of individual identities that has been disentangled from variable visual features in different images of the same person. At earlier stages in the pathway, processing begins in early visual cortex and the occipital face area (OFA) with representations of head view that are invariant across identities, and proceeds to an intermediate level of representation in the fusiform face area (FFA) in which identity is emerging but still entangled with head view. Three-dimensional, view-invariant representation of identities in the rIFFA may be the critical link to the extended system for face perception, affording activation of person knowledge and emotional responses to familiar faces.Significance StatementIn this fMRI decoding experiment, we address how face images are processed in successive stages to disentangle the view-invariant representation of identity from variable visual features. Representations in early visual cortex and the occipital face area distinguish head views, invariant across identities. An intermediate level of representation in the fusiform face area distinguishes identities but still is entangled with head view. The face-processing pathway culminates in the right inferior frontal area with representation of view-independent identity. This paper clarifies the homologies between the human and macaque face processing systems. The findings show further, however, the importance of the inferior frontal cortex in decoding face identity, a result that has not yet been reported in the monkey literature.


2018 ◽  
Vol 30 (7) ◽  
pp. 963-972 ◽  
Author(s):  
Andrew D. Engell ◽  
Na Yeon Kim ◽  
Gregory McCarthy

Perception of faces has been shown to engage a domain-specific set of brain regions, including the occipital face area (OFA) and the fusiform face area (FFA). It is commonly held that the OFA is responsible for the detection of faces in the environment, whereas the FFA is responsible for processing the identity of the face. However, an alternative model posits that the FFA is responsible for face detection and subsequently recruits the OFA to analyze the face parts in the service of identification. An essential prediction of the former model is that the OFA is not sensitive to the arrangement of internal face parts. In the current fMRI study, we test the sensitivity of the OFA and FFA to the configuration of face parts. Participants were shown faces in which the internal parts were presented in a typical configuration (two eyes above a nose above a mouth) or in an atypical configuration (the locations of individual parts were shuffled within the face outline). Perception of the atypical faces evoked a significantly larger response than typical faces in the OFA and in a wide swath of the surrounding posterior occipitotemporal cortices. Surprisingly, typical faces did not evoke a significantly larger response than atypical faces anywhere in the brain, including the FFA (although some subthreshold differences were observed). We propose that face processing in the FFA results in inhibitory sculpting of activation in the OFA, which accounts for this region's weaker response to typical than to atypical configurations.


2011 ◽  
Vol 23 (3) ◽  
pp. 746-756 ◽  
Author(s):  
Vadim Axelrod ◽  
Galit Yovel

The ventral visual cortex has a modular organization in which discrete and well-defined regions show a much stronger response to certain object categories (e.g., faces, bodies) than to other categories. The majority of previous studies have examined the response of these category-selective regions to isolated images of preferred or nonpreferred categories. Thus, little is known about the way these category-selective regions represent more complex visual stimuli, which include both preferred and nonpreferred stimuli. Here we examined whether glasses (nonpreferred) modify the representation of simultaneously presented faces (preferred) in the fusiform face area. We used an event-related fMR-adaptation paradigm in which faces were presented with glasses either on or above the face while subjects performed a face or a glasses discrimination task. Our findings show that the sensitivity of the fusiform face area to glasses was maximal when glasses were presented on the face than above the face during a face discrimination task rather than during a glasses discrimination task. These findings suggest that nonpreferred stimuli may significantly modify the representation of preferred stimuli, even when they are task irrelevant. Future studies will determine whether this interaction is specific to faces or may be found for other object categories in category-selective areas.


2004 ◽  
Vol 16 (9) ◽  
pp. 1669-1679 ◽  
Author(s):  
Emily D. Grossman ◽  
Randolph Blake ◽  
Chai-Youn Kim

Individuals improve with practice on a variety of perceptual tasks, presumably reflecting plasticity in underlying neural mechanisms. We trained observers to discriminate biological motion from scrambled (nonbiological) motion and examined whether the resulting improvement in perceptual performance was accompanied by changes in activation within the posterior superior temporal sulcus and the fusiform “face area,” brain areas involved in perception of biological events. With daily practice, initially naive observers became more proficient at discriminating biological from scrambled animations embedded in an array of dynamic “noise” dots, with the extent of improvement varying among observers. Learning generalized to animations never seen before, indicating that observers had not simply memorized specific exemplars. In the same observers, neural activity prior to and following training was measured using functional magnetic resonance imaging. Neural activity within the posterior superior temporal sulcus and the fusiform “face area” reflected the participants' learning: BOLD signals were significantly larger after training in response both to animations experienced during training and to novel animations. The degree of learning was positively correlated with the amplitude changes in BOLD signals.


2009 ◽  
Vol 30 (4) ◽  
pp. 721-733 ◽  
Author(s):  
Gillian Rhodes ◽  
Patricia T. Michie ◽  
Matthew E. Hughes ◽  
Graham Byatt

2010 ◽  
Vol 104 (1) ◽  
pp. 336-345 ◽  
Author(s):  
Alison Harris ◽  
Geoffrey Karl Aguirre

Although the right fusiform face area (FFA) is often linked to holistic processing, new data suggest this region also encodes part-based face representations. We examined this question by assessing the metric of neural similarity for faces using a continuous carryover functional MRI (fMRI) design. Using faces varying along dimensions of eye and mouth identity, we tested whether these axes are coded independently by separate part-tuned neural populations or conjointly by a single population of holistically tuned neurons. Consistent with prior results, we found a subadditive adaptation response in the right FFA, as predicted for holistic processing. However, when holistic processing was disrupted by misaligning the halves of the face, the right FFA continued to show significant adaptation, but in an additive pattern indicative of part-based neural tuning. Thus this region seems to contain neural populations capable of representing both individual parts and their integration into a face gestalt. A third experiment, which varied the asymmetry of changes in the eye and mouth identity dimensions, also showed part-based tuning from the right FFA. In contrast to the right FFA, the left FFA consistently showed a part-based pattern of neural tuning across all experiments. Together, these data support the existence of both part-based and holistic neural tuning within the right FFA, further suggesting that such tuning is surprisingly flexible and dynamic.


Sign in / Sign up

Export Citation Format

Share Document