scholarly journals Direct comparison of contralateral bias and face/scene selectivity in human occipitotemporal cortex

2021 ◽  
Author(s):  
Edward H. Silson ◽  
Iris I. A. Groen ◽  
Chris I. Baker
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Visual Information ◽  
Large Scale ◽  
Temporal Cortex ◽  
Spatial Location ◽  
Occipital Cortex ◽  
Ventral Surface ◽  
Right Visual Field ◽  
Ventral Temporal Cortex

AbstractHuman visual cortex is organised broadly according to two major principles: retinotopy (the spatial mapping of the retina in cortex) and category-selectivity (preferential responses to specific categories of stimuli). Historically, these principles were considered anatomically separate, with retinotopy restricted to the occipital cortex and category-selectivity emerging in the lateral-occipital and ventral-temporal cortex. However, recent studies show that category-selective regions exhibit systematic retinotopic biases, for example exhibiting stronger activation for stimuli presented in the contra- compared to the ipsilateral visual field. It is unclear, however, whether responses within category-selective regions are more strongly driven by retinotopic location or by category preference, and if there are systematic differences between category-selective regions in the relative strengths of these preferences. Here, we directly compare contralateral and category preferences by measuring fMRI responses to scene and face stimuli presented in the left or right visual field and computing two bias indices: a contralateral bias (response to the contralateral minus ipsilateral visual field) and a face/scene bias (preferred response to scenes compared to faces, or vice versa). We compare these biases within and between scene- and face-selective regions and across the lateral and ventral surfaces of the visual cortex more broadly. We find an interaction between surface and bias: lateral surface regions show a stronger contralateral than face/scene bias, whilst ventral surface regions show the opposite. These effects are robust across and within subjects, and appear to reflect large-scale, smoothly varying gradients. Together, these findings support distinct functional roles for the lateral and ventral visual cortex in terms of the relative importance of the spatial location of stimuli during visual information processing.

scholarly journals Direct comparison of category and spatial selectivity in human occipitotemporal cortex

2021 ◽  
Author(s):  
Edward H Silson ◽  
Iris Isabelle Anna Groen ◽  
Chris I Baker
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Visual Information ◽  
Large Scale ◽  
Spatial Information ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
Right Visual Field ◽  
Ventral Temporal Cortex ◽  
Category Bias

Human visual cortex is organised broadly according to two major principles: retinotopy (the spatial mapping of the retina in cortex) and category-selectivity (preferential responses to specific categories of stimuli). Historically, these principles were considered anatomically separate, with retinotopy restricted to the occipital cortex and category-selectivity emerging in lateral-occipital and ventral-temporal cortex. Contrary to this assumption, recent studies show that category-selective regions exhibit systematic retinotopic biases. It is unclear, however, whether responses within these regions are more strongly driven by retinotopic location or by category preference, and if there are systematic differences between category-selective regions in the relative strengths of these preferences. Here, we directly compare spatial and category preferences by measuring fMRI responses to scene and face stimuli presented in the left or right visual field and computing two bias indices: a spatial bias (response to the contralateral minus ipsilateral visual field) and a category bias (response to the preferred minus non-preferred category). We compare these biases within and between scene- and face-selective regions across the lateral and ventral surfaces of visual cortex. We find an interaction between surface and bias: lateral regions show a stronger spatial than category bias, whilst ventral regions show the opposite. These effects are robust across and within subjects, and reflect large-scale, smoothly varying gradients across both surfaces. Together, these findings support distinct functional roles for lateral and ventral category-selective regions in visual information processing in terms of the relative importance of spatial information.

scholarly journals Changes in thalamocortical connectivity as a potential mechanism of cross-modal plasticity in congenitally blind individuals

2018 ◽  
Author(s):  
Theo Marins ◽  
Maite Russo ◽  
Erika Rodrigues ◽  
jorge Moll ◽  
Daniel Felix ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Cortical Thickness ◽  
Visual Information ◽  
Brain Plasticity ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
Brain Structures ◽  
Congenitally Blind ◽  
Blind Individuals ◽  
Neuroimaging Techniques

ABSTRACTEvidence of cross-modal plasticity in blind individuals has been reported over the past decades showing that non-visual information is carried and processed by classical “visual” brain structures. This feature of the blind brain makes it a pivotal model to explore the limits and mechanisms of brain plasticity. However, despite recent efforts, the structural underpinnings that could explain cross-modal plasticity in congenitally blind individuals remain unclear. Using advanced neuroimaging techniques, we mapped the thalamocortical connectivity and assessed cortical thickness and integrity of white matter of congenitally blind individuals and sighted controls to test the hypothesis that aberrant thalamocortical pattern of connectivity can pave the way for cross-modal plasticity. We described a direct occipital takeover by the temporal projections from the thalamus, which would carry non-visual information (e.g. auditory) to the visual cortex in congenitally blinds. In addition, the amount of thalamo-occipital connectivity correlated with the cortical thickness of primary visual cortex (V1), supporting a probably common (or related) reorganization phenomena. Our results suggest that aberrant thalamocortical connectivity as one possible mechanism of cross-modal plasticity in blinds, with potential impact on cortical thickness of V1.SIGNIFICANT STATEMENTCongenitally blind individuals often develop greater abilities on spared sensory modalities, such as increased acuity in auditory discrimination and voice recognition, when compared to sighted controls. These functional gains have been shown to rely on ‘visual’ cortical areas of the blind brain, characterizing the phenomenon of cross-modal plasticity. However, its anatomical underpinnings in humans have been unsuccessfully pursued for decades. Recent advances of non-invasive neuroimaging techniques allowed us to test the hypothesis of abnormal thalamocortical connectivity in congenitally blinds. Our results showed an expansion of the thalamic connections to the temporal cortex over those that project to the occipital cortex, which may explain, the cross-talk between the visual and auditory systems in congenitally blind individuals.

Interocular torsional disparity and visual cortical development in the cat

1990 ◽  
Vol 64 (4) ◽  
pp. 1352-1360 ◽  
Author(s):  
M. R. Isley ◽  
D. C. Rogers-Ramachandran ◽  
P. G. Shinkman
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Ocular Dominance ◽  
Visual Fields ◽  
Receptive Fields ◽  
Right Visual Field ◽  
Orientation Columns ◽  
Areas 17 And 18 ◽  
The Right ◽  
Visual Cortical

1. The present experiments were designed to assess the effects of relatively large optically induced interocular torsional disparities on the developing kitten visual cortex. Kittens were reared with restricted visual experience. Three groups viewed a normal visual environment through goggles fitted with small prisms that introduced torsional disparities between the left and right eyes' visual fields, equal but opposite in the two eyes. Kittens in the +32 degrees goggle rearing condition experienced a 16 degrees counterclockwise rotation of the left visual field and a 16 degrees clockwise rotation of the right visual field; in the -32 degrees goggle condition the rotations were clockwise in the left eye and counterclockwise in the right. In the control (0 degree) goggle condition, the prisms did not rotate the visual fields. Three additional groups viewed high-contrast square-wave gratings through Polaroid filters arranged to provide a constant 32 degrees of interocular orientation disparity. 2. Recordings were made from neurons in visual cortex around the border of areas 17 and 18 in all kittens. Development of cortical ocular dominance columns was severely disrupted in all the experimental (rotated) rearing conditions. Most cells were classified in the extreme ocular dominance categories 1, 2, 6, and 7. Development of the system of orientation columns was also affected: among the relatively few cells with oriented receptive fields in both eyes, the distributions of interocular disparities in preferred stimulus orientation were centered near 0 degree but showed significantly larger variances than in the control condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Neural Interactions Explains the Activation of Occipital Cortex by an Auditory Stimulus

1998 ◽  
Vol 80 (5) ◽  
pp. 2790-2796 ◽  
Author(s):  
A. R. McIntosh ◽  
R. E. Cabeza ◽  
N. J. Lobaugh
Keyword(s):  
Auditory Stimulus ◽  
Structural Equation ◽  
Large Scale ◽  
Human Subjects ◽  
Premotor Cortex ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
Equation Modeling ◽  
Occipital Area ◽  
Neural Interactions

McIntosh, A. R., R. E. Cabeza, and N. J. Lobaugh. Analysis of neural interactions explains the activation of occipital cortex by an auditory stimulus . J. Neurophysiol. 80: 2790–2796, 1998. Large-scale neural interactions were characterized in human subjects as they learned that an auditory stimulus signaled a visual event. Once learned, activation of left dorsal occipital cortex (increased regional cerebral blood flow) was observed when the auditory stimulus was presented alone. Partial least-squares analysis of the interregional correlations (functional connectivity) between the occipital area and the rest of the brain identified a pattern of covariation with four dominant brain areas that could have mediated this activation: prefrontal cortex (near Brodmann area 10, A10), premotor cortex (A6), superior temporal cortex (A41/42), and contralateral occipital cortex (A18). Interactions among these regions and the occipital area were quantified with structural equation modeling to identify the strongest sources of the effect on left occipital activity (effective connectivity). Learning-related changes in feedback effects from A10 and A41/42 appeared to account for this change in occipital activity. Influences from these areas on the occipital area were initially suppressive, or negative, becoming facilitory, or positive, as the association between the auditory and visual stimuli was acquired. Evaluating the total effects within the functional models showed positive influences throughout the network, suggesting enhanced interactions may have primed the system for the now-expected visual discrimination. By characterizing both changes in activity and the interactions underlying sensory associative learning, we demonstrated how parts of the nervous system operate as a cohesive network in learning about and responding to the environment.

scholarly journals Face inversion reveals holistic processing of peripheral faces

2017 ◽  
Author(s):  
Petra Kovács ◽  
Balázs Knakker ◽  
Petra Hermann ◽  
Gyula Kovács ◽  
Zoltán Vidnyánszky
Keyword(s):  
Visual Field ◽  
Right Hemisphere ◽  
Time Window ◽  
Temporal Cortex ◽  
Discrimination Performance ◽  
Holistic Processing ◽  
Inversion Effect ◽  
Right Visual Field ◽  
Face Inversion Effect ◽  
Face Inversion

AbstractFace perception is accomplished by face-selective neural processes, involving holistic processing that enables highly efficient integration of facial features into a whole face representation. It has been shown that in face-selective regions of the ventral temporal cortex, neural resources involved in holistic processing are primarily dedicated to the central portion of the visual field. These findings raise the intriguing possibility that holistic processing might be the privilege of centrally presented faces and could be strongly diminished in the case of peripheral faces. We addressed this question using the face inversion effect, a well established marker of holistic face processing. The behavioral results revealed impaired identity discrimination performance for inverted peripheral faces scaled according to the V1 magnification factor, compared to upright presented faces. The size of peripheral face inversion effect (FIE) was comparable to that found for centrally displayed faces. Face inversion affected the early ERP responses to faces in two time intervals. The earliest FIE was most pronounced in the time window between 130-140 ms following stimulus presentation, for both centrally and peripherally displayed faces and in the latter case, it was present only over the contralateral hemisphere. The timing of the next component FIE corresponded closely with the temporal interval of the N170 ERP component and showed strong right hemisphere lateralization, both when faces were displayed in the left or right visual field. Furthermore, we also showed that centrally presented face masks impaired peripheral face identity discrimination performance, but did not reduce the magnitude of the FIE. These findings revealed robust behavioral and neural inversion effects for peripheral faces and thus suggest that faces are processed holistically throughout the visual field.HighlightsRobust behavioral and neural inversion effect was found for peripheral faces.P1 ERP component is modulated by inverted central and contralateral faces.N170 ERP component is modulated by centrally and peripherally presented faces.Neural face inversion effect shows strong right hemisphere lateralization.Faces are processed holistically throughout the visual field.

scholarly journals A Probabilistic Functional Atlas of Human Occipito-Temporal Visual Cortex

2020 ◽  
Vol 31 (1) ◽  
pp. 603-619 ◽  
Author(s):  
Mona Rosenke ◽  
Rick van Hoof ◽  
Job van den Hurk ◽  
Kalanit Grill-Spector ◽  
Rainer Goebel
Keyword(s):  
Visual Cortex ◽  
Visual Processing ◽  
Large Body ◽  
Temporal Cortex ◽  
Region Of Interest ◽  
Brain Regions ◽  
Functional Region ◽  
Accurate Localization ◽  
Imaging Research ◽  
Ventral Temporal Cortex

Abstract Human visual cortex contains many retinotopic and category-specific regions. These brain regions have been the focus of a large body of functional magnetic resonance imaging research, significantly expanding our understanding of visual processing. As studying these regions requires accurate localization of their cortical location, researchers perform functional localizer scans to identify these regions in each individual. However, it is not always possible to conduct these localizer scans. Here, we developed and validated a functional region of interest (ROI) atlas of early visual and category-selective regions in human ventral and lateral occipito-temporal cortex. Results show that for the majority of functionally defined ROIs, cortex-based alignment results in lower between-subject variability compared to nonlinear volumetric alignment. Furthermore, we demonstrate that 1) the atlas accurately predicts the location of an independent dataset of ventral temporal cortex ROIs and other atlases of place selectivity, motion selectivity, and retinotopy. Next, 2) we show that the majority of voxel within our atlas is responding mostly to the labeled category in a left-out subject cross-validation, demonstrating the utility of this atlas. The functional atlas is publicly available (download.brainvoyager.com/data/visfAtlas.zip) and can help identify the location of these regions in healthy subjects as well as populations (e.g., blind people, infants) in which functional localizers cannot be run.

scholarly journals Evoked potentials in large-scale cortical networks elicited by TMS of the visual cortex

2011 ◽  
Vol 106 (4) ◽  
pp. 1734-1746 ◽  
Author(s):  
Javier O. Garcia ◽  
Emily D. Grossman ◽  
Ramesh Srinivasan
Keyword(s):  
Visual Cortex ◽  
Visual System ◽  
Large Scale ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Temporal Region ◽  
Stimulation Site ◽  
Stimulation Intensity ◽  
Virtual Lesion ◽  
Cortical Regions

Single pulses of transcranial magnetic stimulation (TMS) result in distal and long-lasting oscillations, a finding directly challenging the virtual lesion hypothesis. Previous research supporting this finding has primarily come from stimulation of the motor cortex. We have used single-pulse TMS with simultaneous EEG to target seven brain regions, six of which belong to the visual system [left and right primary visual area V1, motion-sensitive human middle temporal cortex, and a ventral temporal region], as determined with functional MRI-guided neuronavigation, and a vertex “control” site to measure the network effects of the TMS pulse. We found the TMS-evoked potential (TMS-EP) over visual cortex consists mostly of site-dependent theta- and alphaband oscillations. These site-dependent oscillations extended beyond the stimulation site to functionally connected cortical regions and correspond to time windows where the EEG responses maximally diverge (40, 200, and 385 ms). Correlations revealed two site-independent oscillations ∼350 ms after the TMS pulse: a theta-band oscillation carried by the frontal cortex, and an alpha-band oscillation over parietal and frontal cortical regions. A manipulation of stimulation intensity at one stimulation site (right hemisphere V1-V3) revealed sensitivity to the stimulation intensity at different regions of cortex, evidence of intensity tuning in regions distal to the site of stimulation. Together these results suggest that a TMS pulse applied to the visual cortex has a complex effect on brain function, engaging multiple brain networks functionally connected to the visual system with both invariant and site-specific spatiotemporal dynamics. With this characterization of TMS, we propose an alternative to the virtual lesion hypothesis. Rather than a technique that simulates lesions, we propose TMS generates natural brain signals and engages functional networks.

scholarly journals Attending to What and Where: Background Connectivity Integrates Categorical and Spatial Attention

2018 ◽  
Vol 30 (9) ◽  
pp. 1281-1297 ◽  
Author(s):  
Alexa Tompary ◽  
Naseem Al-Aidroos ◽  
Nicholas B. Turk-Browne
Keyword(s):  
Visual Cortex ◽  
Spatial Attention ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Neural Basis ◽  
Attentional Modulation ◽  
Temporal Correlations ◽  
Visual Areas ◽  
Early Visual Cortex ◽  
Ventral Temporal Cortex

Top–down attention prioritizes the processing of goal-relevant information throughout visual cortex based on where that information is found in space and what it looks like. Whereas attentional goals often have both spatial and featural components, most research on the neural basis of attention has examined these components separately. Here we investigated how these attentional components are integrated by examining the attentional modulation of functional connectivity between visual areas with different selectivity. Specifically, we used fMRI to measure temporal correlations between spatially selective regions of early visual cortex and category-selective regions in ventral temporal cortex while participants performed a task that benefitted from both spatial and categorical attention. We found that categorical attention modulated the connectivity of category-selective areas, but only with retinotopic areas that coded for the spatially attended location. Similarly, spatial attention modulated the connectivity of retinotopic areas only with the areas coding for the attended category. This pattern of results suggests that attentional modulation of connectivity is driven both by spatial selection and featural biases. Combined with exploratory analyses of frontoparietal areas that track these changes in connectivity among visual areas, this study begins to shed light on how different components of attention are integrated in support of more complex behavioral goals.

scholarly journals Typical visual-field locations enhance processing in object-selective channels of human occipital cortex

2018 ◽  
Vol 120 (2) ◽  
pp. 848-853 ◽  
Author(s):  
Daniel Kaiser ◽  
Radoslaw M. Cichy
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Functional Mri ◽  
Object Perception ◽  
Occipital Cortex ◽  
Natural Environments ◽  
Lower Visual Field ◽  
Cortical Processing ◽  
Upper Visual Field ◽  
Early Visual Cortex

Natural environments consist of multiple objects, many of which repeatedly occupy similar locations within a scene. For example, hats are seen on people’s heads, while shoes are most often seen close to the ground. Such positional regularities bias the distribution of objects across the visual field: hats are more often encountered in the upper visual field, while shoes are more often encountered in the lower visual field. Here we tested the hypothesis that typical visual field locations of objects facilitate cortical processing. We recorded functional MRI while participants viewed images of objects that were associated with upper or lower visual field locations. Using multivariate classification, we show that object information can be more successfully decoded from response patterns in object-selective lateral occipital cortex (LO) when the objects are presented in their typical location (e.g., shoe in the lower visual field) than when they are presented in an atypical location (e.g., shoe in the upper visual field). In a functional connectivity analysis, we relate this benefit to increased coupling between LO and early visual cortex, suggesting that typical object positioning facilitates information propagation across the visual hierarchy. Together these results suggest that object representations in occipital visual cortex are tuned to the structure of natural environments. This tuning may support object perception in spatially structured environments. NEW & NOTEWORTHY In the real world, objects appear in predictable spatial locations. Hats, commonly appearing on people’s heads, often fall into the upper visual field. Shoes, mostly appearing on people’s feet, often fall into the lower visual field. Here we used functional MRI to demonstrate that such regularities facilitate cortical processing: Objects encountered in their typical locations are coded more efficiently, which may allow us to effortlessly recognize objects in natural environments.

Sign in / Sign up

Export Citation Format

Share Document