Atypical Retinotopic Organization of Visual Cortex in Patients with Central Brain Damage: Congenital and Adult Onset

SummaryOne hallmark of the visual system is the strict retinotopic organization from the periphery towards the central brain, spanning multiple layers of synaptic integration. Recent Drosophila studies on the computation of distinct visual features have shown that retinotopic representation is often lost beyond the optic lobes, due to convergence of columnar neuron types onto optic glomeruli. Nevertheless, functional imaging revealed a spatially accurate representation of visual cues in the central complex (CX), raising the question how this is implemented on a circuit level. By characterizing the afferents to a specific visual glomerulus, the anterior optic tubercle (AOTU), we discovered a spatial segregation of topographic versus non-topographic projections from molecularly distinct classes of medulla projection neurons (medullo-tubercular, or MeTu neurons). Distinct classes of topographic versus non-topographic MeTus form parallel channels, terminating in separate AOTU domains. Both types then synapse onto separate matching topographic fields of tubercular-bulbar (TuBu) neurons which relay visual information towards the dendritic fields of central complex ring neurons in the bulb neuropil, where distinct bulb sectors correspond to a distinct ring domain in the ellipsoid body. Hence, peripheral topography is maintained due to stereotypic circuitry within each TuBu class, providing the structural basis for spatial representation of visual information in the central complex. Together with previous data showing rough topography of lobula projections to a different AOTU subunit, our results further highlight the AOTUs role as a prominent relay station for spatial information from the retina to the central brain.

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Reduced spatial integration in the ventral visual cortex underlies face recognition deficits in developmental prosopagnosia

10.1101/051102 ◽

2016 ◽

Cited By ~ 9

Author(s):

Nathan Witthoft ◽

Sonia Poltoratski ◽

Mai Nguyen ◽

Golijeh Golarai ◽

Alina Liberman ◽

...

Keyword(s):

Face Recognition ◽

Visual Cortex ◽

Face Processing ◽

Receptive Fields ◽

Spatial Integration ◽

Brain Abnormalities ◽

Neural Basis ◽

Recognition Ability ◽

Visual Areas ◽

Retinotopic Organization

Developmental prosopagnosia (DP) is characterized by deficits in face recognition without gross brain abnormalities. However, the neural basis of DP is not well understood. We measured population receptive fields (pRFs) in ventral visual cortex of DPs and typical adults to assess the contribution of spatial integration to face processing. While DPs showed typical retinotopic organization of ventral visual cortex and normal pRF sizes in early visual areas, we found significantly reduced pRF sizes in face-selective regions and in intermediate areas hV4 and VO1. Across both typicals and DPs, face recognition ability correlated positively with pRF size in both face-selective regions and VO1, whereby participants with larger pRFs perform better. However, face recognition ability is correlated with both pRF size and ROI volume only in face-selective regions. These findings suggest that smaller pRF sizes in DP may reflect a deficit in spatial integration affecting holistic processing required for face recognition.

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Retinotopy versus Face Selectivity in Macaque Visual Cortex

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00672 ◽

2014 ◽

Vol 26 (12) ◽

pp. 2691-2700 ◽

Cited By ~ 17

Author(s):

Reza Rajimehr ◽

Natalia Y. Bilenko ◽

Wim Vanduffel ◽

Roger B. H. Tootell

Keyword(s):

Visual Cortex ◽

Nonhuman Primates ◽

Polar Angle ◽

Object Categories ◽

Retinotopic Maps ◽

Specific Object ◽

Retinotopic Organization ◽

Face Selectivity ◽

Face Stimuli ◽

Visual Cortical

Retinotopic organization is a ubiquitous property of lower-tier visual cortical areas in human and nonhuman primates. In macaque visual cortex, the retinotopic maps extend to higher-order areas in the ventral visual pathway, including area TEO in the inferior temporal (IT) cortex. Distinct regions within IT cortex are also selective to specific object categories such as faces. Here we tested the topographic relationship between retinotopic maps and face-selective patches in macaque visual cortex using high-resolution fMRI and retinotopic face stimuli. Distinct subregions within face-selective patches showed either (1) a coarse retinotopic map of eccentricity and polar angle, (2) a retinotopic bias to a specific location of visual field, or (3) nonretinotopic selectivity. In general, regions along the lateral convexity of IT cortex showed more overlap between retinotopic maps and face selectivity, compared with regions within the STS. Thus, face patches in macaques can be subdivided into smaller patches with distinguishable retinotopic properties.

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Retinotopic organization of striate and extrastriate visual cortex in the hooded rat

Brain Research ◽

10.1016/0006-8993(83)90370-0 ◽

1983 ◽

Vol 272 (1) ◽

pp. 137-144 ◽

Cited By ~ 111

Author(s):

Sergio G. Espinoza ◽

Hardy C. Thomas

Keyword(s):

Visual Cortex ◽

Extrastriate Visual Cortex ◽

Retinotopic Organization

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Retinotopic and nonretinotopic field potentials in cat visual cortex

Visual Neuroscience ◽

10.1017/s0952523800003904 ◽

1994 ◽

Vol 11 (5) ◽

pp. 953-977 ◽

Cited By ~ 33

Author(s):

M. Kitano ◽

K. Niiyama ◽

T. Kasamatsu ◽

E. E. Sutter ◽

A. M. Norcia

Keyword(s):

Visual Cortex ◽

Receptive Field ◽

Peak Latency ◽

Conduction Delay ◽

Field Potentials ◽

Local Component ◽

Cat Visual Cortex ◽

Retinotopic Organization ◽

Nonlinear Integration ◽

Inhibitory Interactions

AbstractTwo types of field potentials were identified in cat visual cortex using contrast reversal of oriented bar gratings: a short-latency fast-local component with a retinotopic organization similar to that seen with single-unit discharges at the same cortical site, and a slow, nonretinotopic component with a longer peak latency. The slow-distributed component had an extensive receptive field mapped by measuring the amplitude of binary kernels and showed strong inhibitory interactions within the receptive field. The peak latency of the slow-local component increased with distance from the retinotopic center, suggesting a possible conduction delay. Both components showed some orientation bias depending on the laminar location, but the bias could be independent of the orientation preferred by single units in the immediate vicinity. The present findings indicate that locally generated field potentials reflect cortical mechanisms for nonlinear integration over wide areas of the visual field.

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