Differential spatial computations in ventral and lateral face-selective regions are scaffolded by structural connections

2020 ◽  
Author(s):  
Dawn Finzi ◽  
Jesse Gomez ◽  
Marisa Nordt ◽  
Alex A. Rezai ◽  
Sonia Poltoratski ◽  
...  
Keyword(s):  
Visual Cortex ◽  
White Matter ◽  
Receptive Field ◽  
Face Processing ◽  
Diffusion Mri ◽  
Lateral Face ◽  
Fine Grain ◽  
Early Visual Cortex ◽  
Structural Connections ◽  
High Level

AbstractFace-processing occurs across ventral and lateral visual streams, which are involved in static and dynamic face perception, respectively. However, the nature of spatial computations across streams is unknown. Using functional MRI and novel population receptive field (pRF) mapping, we measured pRFs in face-selective regions. Results reveal that spatial computations by pRFs in ventral face-selective regions are concentrated around the center of gaze (fovea), but spatial computations in lateral face-selective regions extend peripherally. Diffusion MRI reveals that these differences are mirrored by a preponderance of white matter connections between ventral face-selective regions and foveal early visual cortex (EVC), while connections with lateral regions are distributed more uniformly across EVC eccentricities. These findings suggest a rethinking of spatial computations in face-selective regions, showing that they vary across ventral and lateral streams, and further propose that spatial computations in high-level regions are scaffolded by the fine-grain pattern of white matter connections from EVC.

scholarly journals Differential spatial computations in ventral and lateral face-selective regions are scaffolded by structural connections

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dawn Finzi ◽  
Jesse Gomez ◽  
Marisa Nordt ◽  
Alex A. Rezai ◽  
Sonia Poltoratski ◽  
...  
Keyword(s):  
Visual Cortex ◽  
White Matter ◽  
Receptive Field ◽  
Face Processing ◽  
Diffusion Mri ◽  
Lateral Face ◽  
Fine Grain ◽  
Early Visual Cortex ◽  
Structural Connections ◽  
High Level

AbstractFace-processing occurs across ventral and lateral visual streams, which are involved in static and dynamic face perception, respectively. However, the nature of spatial computations across streams is unknown. Using functional MRI and population receptive field (pRF) mapping, we measured pRFs in face-selective regions. Results reveal that spatial computations by pRFs in ventral face-selective regions are concentrated around the center of gaze (fovea), but spatial computations in lateral face-selective regions extend peripherally. Diffusion MRI reveals that these differences are mirrored by a preponderance of white matter connections between ventral face-selective regions and foveal early visual cortex (EVC), while connections with lateral regions are distributed more uniformly across EVC eccentricities. These findings suggest a rethinking of spatial computations in face-selective regions, showing that they vary across ventral and lateral streams, and further propose that spatial computations in high-level regions are scaffolded by the fine-grain pattern of white matter connections from EVC.

scholarly journals Disentangling the representation of identity from head view along the human face processing pathway

2016 ◽  
Author(s):  
J. Swaroop Guntupalli ◽  
Kelsey G. Wheeler ◽  
M. Ida Gobbini
Keyword(s):  
Visual Cortex ◽  
Frontal Cortex ◽  
Face Perception ◽  
Face Processing ◽  
Visual Features ◽  
Fusiform Face Area ◽  
Invariant Representation ◽  
Face Area ◽  
Early Visual Cortex ◽  
Occipital Face Area

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.

scholarly journals Radial asymmetries in population receptive field size and cortical magnification factor in early visual cortex

2017 ◽  
Vol 17 (10) ◽  
pp. 587
Author(s):  
Ben Harvey ◽  
Jan Brascamp ◽  
Sónia Ferreira ◽  
Miguel Castelo-Branco ◽  
Serge Dumoulin ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Field Size ◽  
Magnification Factor ◽  
Receptive Field Size ◽  
Early Visual Cortex ◽  
Cortical Magnification ◽  
Cortical Magnification Factor

scholarly journals Widespread Suppression of High-Order Visual Cortex During Blinks and External Predictable Visual Interruptions

2018 ◽  
Author(s):  
Tal Golan ◽  
Shany Grossman ◽  
Leon Y Deouell ◽  
Rafael Malach
Keyword(s):  
Visual Cortex ◽  
Visual Awareness ◽  
General Purpose ◽  
High Order ◽  
Still Images ◽  
Visual Hierarchy ◽  
Retinal Input ◽  
Early Visual Cortex ◽  
High Level

AbstractSpontaneous eye blinks generate frequent potent interruptions to the retinal input and yet go unnoticed. As such, they provide an attractive approach to the study of the neural correlates of visual awareness. Here, we tested the potential role of predictability in generating blink-related effects using fMRI. While participants attentively watched still images of faces and houses, we monitored naturally occurring spontaneous blinks and introduced three kinds of matched visual interruptions: cued voluntary blinks, self-initiated (and hence, predictable) external darkenings, and physically similar but unpredictable external darkenings. These events’ impact was inspected using fMRI across the visual hierarchy. In early visual cortex, both spontaneous and voluntary blinks, as well as predictable and unpredictable external darkenings, led to largely similar positive responses in peripheral representations. In mid- and high-level visual cortex, all predictable conditions (spontaneous blinks, voluntary blinks, and self-initiated external darkenings) were associated with signal decreases. In contrast, unpredictable darkenings were associated with signal increases. These findings suggest that general-purpose prediction-related mechanisms are involved in producing a small but widespread suppression of mid- and high-order visual regions during blinks. Such suppression may down-regulate responses to predictable transients in the human visual hierarchy.

scholarly journals Population receptive field and connectivity properties of the early visual cortex in human albinism

NeuroImage ◽  
2019 ◽  
Vol 202 ◽  
pp. 116105 ◽  
Author(s):  
Khazar Ahmadi ◽  
Anne Herbik ◽  
Markus Wagner ◽  
Martin Kanowski ◽  
Hagen Thieme ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Early Visual Cortex

scholarly journals Spontaneously emerging patterns in human visual cortex and their functional connectivity are linked to the patterns evoked by visual stimuli

2020 ◽  
Vol 124 (5) ◽  
pp. 1343-1363
Author(s):  
DoHyun Kim ◽  
Tomer Livne ◽  
Nicholas V. Metcalf ◽  
Maurizio Corbetta ◽  
Gordon L. Shulman
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Spontaneous Activity ◽  
Spatial Patterns ◽  
Brain Activity ◽  
Spontaneous Brain Activity ◽  
Emerging Patterns ◽  
Early Visual Cortex ◽  
Functional Explanations ◽  
High Level

Spontaneous brain activity was once thought to reflect only noise, but evidence of strong spatiotemporal regularities has motivated a search for functional explanations. Here we show that the spatial pattern of spontaneous activity in human high-level and early visual cortex is related to the spatial patterns evoked by stimuli. Moreover, these patterns partly govern spontaneous spatiotemporal interactions between regions, so-called functional connectivity. These results support the hypothesis that spontaneous activity serves a representational function.

Radial asymmetries in population receptive field size and cortical magnification factor in early visual cortex

NeuroImage ◽  
2018 ◽  
Vol 167 ◽  
pp. 41-52 ◽  
Author(s):  
Maria Fatima Silva ◽  
Jan W. Brascamp ◽  
Sónia Ferreira ◽  
Miguel Castelo-Branco ◽  
Serge O. Dumoulin ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Field Size ◽  
Magnification Factor ◽  
Receptive Field Size ◽  
Early Visual Cortex ◽  
Cortical Magnification ◽  
Cortical Magnification Factor

scholarly journals Population receptive field shapes in early visual cortex are nearly circular

2020 ◽  
Author(s):  
Garikoitz Lerma-Usabiaga ◽  
Jonathan Winawer ◽  
Brian A. Wandell
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Receptive Field ◽  
Receptive Fields ◽  
Ground Truth ◽  
Central Position ◽  
Data Set ◽  
Ground Truth Data ◽  
Aspect Ratios ◽  
Early Visual Cortex

AbstractThe visual field region where a stimulus evokes a neural response is called the receptive field (RF). Analytical tools combined with functional MRI can estimate the receptive field of the population of neurons within a voxel. Circular population RF (pRF) methods accurately specify the central position of the pRF and provide some information about the spatial extent (diameter) of the receptive field. A number of investigators developed methods to further estimate the shape of the pRF, for example whether the shape is more circular or elliptical. There is a report that there are many pRFs with highly elliptical pRFs in early visual cortex (V1-V3; Silson et al., 2018). Large aspect ratios (>2) are difficult to reconcile with the spatial scale of orientation columns or visual field map properties in early visual cortex. We started to replicate the experiments and found that the software used in the publication does not accurately estimate RF shape: it produces elliptical fits to circular ground-truth data. We analyzed an independent data set with a different software package that was validated over a specific range of measurement conditions, to show that in early visual cortex the aspect ratios are less than 2. Furthermore, current empirical and theoretical methods do not have enough precision to discriminate ellipses with aspect ratios of 1.5 from circles. Through simulation we identify methods for improving sensitivity that may estimate ellipses with smaller aspect ratios. The results we present are quantitatively consistent with prior assessments using other methodologies.Significance StatementWe evaluated whether the shape of many population receptive fields in early visual cortex is elliptical and differs substantially from circular. We evaluated two tools for estimating elliptical models of the pRF; one tool was valid over the measured compliance range. Using the validated tool, we found no evidence that confidently rejects circular fits to the pRF in visual field maps V1, V2 and V3. The new measurements and analyses are consistent with prior theoretical and experimental assessments in the literature.

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