Nonvisual and Visual Object Shape Representations in Occipitotemporal Cortex: Evidence from Congenitally Blind and Sighted Adults

Previous studies have provided evidence for a tool-selective region in left lateral occipitotemporal cortex (LOTC). This region responds selectively to pictures of tools and to characteristic visual tool motion. The present human fMRI study tested whether visual experience is required for the development of tool-selective responses in left LOTC. Words referring to tools, animals, and nonmanipulable objects were presented auditorily to 14 congenitally blind and 16 sighted participants. Sighted participants additionally viewed pictures of these objects. In whole-brain group analyses, sighted participants showed tool-selective activity in left LOTC in both visual and auditory tasks. Importantly, virtually identical tool-selective LOTC activity was found in the congenitally blind group performing the auditory task. Furthermore, both groups showed equally strong tool-selective activity for auditory stimuli in a tool-selective LOTC region defined by the picture-viewing task in the sighted group. Detailed analyses in individual participants showed significant tool-selective LOTC activity in 13 of 14 blind participants and 14 of 16 sighted participants. The strength and anatomical location of this activity were indistinguishable across groups. Finally, both blind and sighted groups showed significant resting state functional connectivity between left LOTC and a bilateral frontoparietal network. Together, these results indicate that tool-selective activity in left LOTC develops without ever having seen a tool or its motion. This finding puts constraints on the possible role that this region could have in tool processing and, more generally, provides new insights into the principles shaping the functional organization of OTC.

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Pixels, Voxels, and Views: A Study of Shape Representations for Single View 3D Object Shape Prediction

2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition ◽

10.1109/cvpr.2018.00323 ◽

2018 ◽

Cited By ~ 32

Author(s):

Daeyun Shin ◽

Charless C. Fowlkes ◽

Derek Hoiem

Keyword(s):

Shape Representations ◽

Object Shape ◽

3D Object ◽

Single View ◽

Shape Prediction

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Effect of Using Object Shape Prior on Visual Object Counting

2018 IEEE Visual Communications and Image Processing (VCIP) ◽

10.1109/vcip.2018.8698634 ◽

2018 ◽

Author(s):

Minki Jeong ◽

Changick Kim

Keyword(s):

Visual Object ◽

Shape Prior ◽

Object Shape ◽

Object Counting

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Disentangling Representations of Object Shape and Object Category in Human Visual Cortex: The Animate–Inanimate Distinction

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00924 ◽

2016 ◽

Vol 28 (5) ◽

pp. 680-692 ◽

Cited By ~ 71

Author(s):

Daria Proklova ◽

Daniel Kaiser ◽

Marius V. Peelen

Keyword(s):

Visual Cortex ◽

Activity Patterns ◽

Temporal Cortex ◽

Brain Regions ◽

Visual Object ◽

Object Category ◽

Human Visual Cortex ◽

Object Properties ◽

Occipitotemporal Cortex ◽

Visual Properties

Objects belonging to different categories evoke reliably different fMRI activity patterns in human occipitotemporal cortex, with the most prominent distinction being that between animate and inanimate objects. An unresolved question is whether these categorical distinctions reflect category-associated visual properties of objects or whether they genuinely reflect object category. Here, we addressed this question by measuring fMRI responses to animate and inanimate objects that were closely matched for shape and low-level visual features. Univariate contrasts revealed animate- and inanimate-preferring regions in ventral and lateral temporal cortex even for individually matched object pairs (e.g., snake–rope). Using representational similarity analysis, we mapped out brain regions in which the pairwise dissimilarity of multivoxel activity patterns (neural dissimilarity) was predicted by the objects' pairwise visual dissimilarity and/or their categorical dissimilarity. Visual dissimilarity was measured as the time it took participants to find a unique target among identical distractors in three visual search experiments, where we separately quantified overall dissimilarity, outline dissimilarity, and texture dissimilarity. All three visual dissimilarity structures predicted neural dissimilarity in regions of visual cortex. Interestingly, these analyses revealed several clusters in which categorical dissimilarity predicted neural dissimilarity after regressing out visual dissimilarity. Together, these results suggest that the animate–inanimate organization of human visual cortex is not fully explained by differences in the characteristic shape or texture properties of animals and inanimate objects. Instead, representations of visual object properties and object category may coexist in more anterior parts of the visual system.

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Orthographic Priming in Braille Reading as Evidence for Task-specific Reorganization in the Ventral Visual Cortex of the Congenitally Blind

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01407 ◽

2019 ◽

Vol 31 (7) ◽

pp. 1065-1078

Author(s):

Katarzyna Rączy ◽

Aleksandra Urbańczyk ◽

Maksymilian Korczyk ◽

Jakub Michał Szewczyk ◽

Ewa Sumera ◽

...

Keyword(s):

Orthographic Processing ◽

Sentence Structure ◽

Input Modality ◽

Double Dissociation ◽

Repetition Suppression ◽

Congenitally Blind ◽

Auditory Priming ◽

Occipitotemporal Cortex ◽

Orthographic Priming ◽

Language Areas

The task-specific principle asserts that, following deafness or blindness, the deprived cortex is reorganized in a manner such that the task of a given area is preserved even though its input modality has been switched. Accordingly, tactile reading engages the ventral occipitotemporal cortex (vOT) in the blind in a similar way to regular reading in the sighted. Others, however, show that the vOT of the blind processes spoken sentence structure, which suggests that the task-specific principle might not apply to vOT. The strongest evidence for the vOT's engagement in sighted reading comes from orthographic repetition–suppression studies. Here, congenitally blind adults were tested in an fMRI repetition–suppression paradigm. Results reveal a double dissociation, with tactile orthographic priming in the vOT and auditory priming in general language areas. Reconciling our finding with other evidence, we propose that the vOT in the blind serves multiple functions, one of which, orthographic processing, overlaps with its function in the sighted.

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Haptic Shape Processing in Visual Cortex

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00548 ◽

2014 ◽

Vol 26 (5) ◽

pp. 1154-1167 ◽

Cited By ~ 19

Author(s):

Jacqueline C. Snow ◽

Lars Strother ◽

Glyn W. Humphreys

Keyword(s):

Visual Cortex ◽

Object Recognition ◽

Primary Visual Cortex ◽

Shape Recognition ◽

Visual Object ◽

Visual Object Recognition ◽

Object Shape ◽

Shape Processing ◽

Shape Selective ◽

Visual Cortical

Humans typically rely upon vision to identify object shape, but we can also recognize shape via touch (haptics). Our haptic shape recognition ability raises an intriguing question: To what extent do visual cortical shape recognition mechanisms support haptic object recognition? We addressed this question using a haptic fMRI repetition design, which allowed us to identify neuronal populations sensitive to the shape of objects that were touched but not seen. In addition to the expected shape-selective fMRI responses in dorsal frontoparietal areas, we observed widespread shape-selective responses in the ventral visual cortical pathway, including primary visual cortex. Our results indicate that shape processing via touch engages many of the same neural mechanisms as visual object recognition. The shape-specific repetition effects we observed in primary visual cortex show that visual sensory areas are engaged during the haptic exploration of object shape, even in the absence of concurrent shape-related visual input. Our results complement related findings in visually deprived individuals and highlight the fundamental role of the visual system in the processing of object shape.

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Shape coding in occipito-temporal cortex relies on object silhouette, curvature and medial-axis

10.1101/814251 ◽

2019 ◽

Author(s):

Paolo Papale ◽

Andrea Leo ◽

Giacomo Handjaras ◽

Luca Cecchetti ◽

Pietro Pietrini ◽

...

Keyword(s):

Medial Axis ◽

Temporal Cortex ◽

Brain Regions ◽

Local Contrast ◽

Object Representations ◽

Shape Representations ◽

Object Shape ◽

Visual Hierarchy ◽

Real Objects ◽

Brain Processing

AbstractObject recognition relies on different transformations of the retinal input, carried out by the visual system, that range from local contrast to object shape and category. While some of those transformations are thought to occur at specific stages of the visual hierarchy, the features they represent are correlated (e.g., object shape and identity) and selectivity for the same feature overlaps in many brain regions. This may be explained either by collinearity across representations, or may instead reflect the coding of multiple dimensions by the same cortical population. Moreover, orthogonal and shared components may differently impact on distinctive stages of the visual hierarchy. We recorded functional MRI (fMRI) activity while participants passively attended to object images and employed a statistical approach that partitioned orthogonal and shared object representations to reveal their relative impact on brain processing. Orthogonal shape representations (silhouette, curvature and medial-axis) independently explained distinct and overlapping clusters of selectivity in occitotemporal (OTC) and parietal cortex. Moreover, we show that the relevance of shared representations linearly increases moving from posterior to anterior regions. These results indicate that the visual cortex encodes shared relations between different features in a topographic fashion and that object shape is encoded along different dimensions, each representing orthogonal features.New & NoteworthyThere are several possible ways of characterizing the shape of an object. Which shape description better describes our brain responses while we passively perceive objects? Here, we employed three competing shape models to explain brain representations when viewing real objects. We found that object shape is encoded in a multi-dimensional fashion and thus defined by the interaction of multiple features.

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Distinctive Neural Mechanisms Supporting Visual Object Individuation and Identification

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2008.21024 ◽

2009 ◽

Vol 21 (3) ◽

pp. 511-518 ◽

Cited By ~ 66

Author(s):

Yaoda Xu

Keyword(s):

Object Identification ◽

Fixed Number ◽

Visual Object ◽

Object Processing ◽

Object Individuation ◽

Object Shape ◽

Lateral Occipital Complex ◽

Visual Objects ◽

Unique Object ◽

Object Shapes

Many everyday activities, such as driving on a busy street, require the encoding of distinctive visual objects from crowded scenes. Given resource limitations of our visual system, one solution to this difficult and challenging task is to first select individual objects from a crowded scene (object individuation) and then encode their details (object identification). Using functional magnetic resonance imaging, two distinctive brain mechanisms were recently identified that support these two stages of visual object processing. While the inferior intraparietal sulcus (IPS) selects a fixed number of about four objects via their spatial locations, the superior IPS and the lateral occipital complex (LOC) encode the features of a subset of the selected objects in great detail (object shapes in this case). Thus, the inferior IPS individuates visual objects from a crowded display and the superior IPS and higher visual areas participate in subsequent object identification. Consistent with the prediction of this theory, even when only object shape identity but not its location is task relevant, this study shows that object individuation in the inferior IPS treats four identical objects similarly as four objects that are all different, whereas object shape identification in the superior IPS and the LOC treat four identical objects as a single unique object. These results provide independent confirmation supporting the dissociation between visual object individuation and identification in the brain.

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