Functional specialization in the lower and upper visual fields in humans: Its ecological origins and neurophysiological implications

AbstractFunctional specialization in the lower and upper visual fields in humans is analyzed in relation to the origins of the primate visual system. Processing differences between the vertical hemifields are related to the distinction between near (peripersonal) and far (extrapersonal) space, which are biased toward the lower and upper visual fields, respectively. Nonlinear/global processing is required in the lower visual field in order to pergeive the optically degraded and diplopic images in near vision, whereas objects in far vision are searched for and recognized primarily using linear/local perceptual mechanisms. The functional differences between near and far visual space are correlated with their disproportionate representations in the dorsal and ventral divisions of visual association cortex, respectively, and in the magnocellular and parvocellular pathways that project to them. Advances in far visual capabilities and forelimb manipulatory skills may have led to a significant enhancement of these functional specializations.

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Visual numerosity estimation is based on anisotropic representations of visual space

10.31219/osf.io/urg3j ◽

2021 ◽

Author(s):

Miao Li ◽

Bert Reynvoet ◽

Bilge Sayim

Keyword(s):

Visual Field ◽

Convex Hull ◽

Visual Fields ◽

Spatial Vision ◽

Visual Space ◽

Stimulus Features ◽

Numerosity Estimation ◽

Numerosity Perception ◽

Average Eccentricity ◽

Shed Light

Humans can estimate the number of visually displayed items without counting. This capacity of numerosity perception has often been attributed to a dedicated system to estimate numerosity, or alternatively to the exploitation of various stimulus features, such as density, convex hull, the size of items and occupancy area. The distribution of the presented items is usually not varied with eccentricity in the visual field. However, our visual fields are highly asymmetric, and to date, it is unclear how inhomogeneities of the visual field impact numerosity perception. Besides eccentricity, a pronounced asymmetry is the radial-tangential anisotropy. For example, in crowding, radially placed flankers interfere more strongly with target perception than tangentially placed flankers. Similarly, in redundancy masking, the number of perceived items in repeating patterns is reduced when the items are arranged radially but not when they are arranged tangentially. Here, we investigated whether numerosity perception is subject to the radial-tangential anisotropy of spatial vision to shed light on the underlying topology of numerosity perception. Observers were presented with varying numbers of discs and asked to report the perceived number. There were two conditions. Discs were predominantly arranged radially in the “radial” condition and tangentially in the “tangential” condition. Additionally, the spacing between discs was scaled with eccentricity. Physical properties, such as average eccentricity, average spacing, convex hull, and density were kept as similar as possible in the two conditions. Radial arrangements were expected to yield underestimation compared to tangential arrangements. Consistent with the hypothesis, numerosity estimates in the radial condition were lower compared to the tangential condition. Magnitudes of radial alignment (as well as predicted crowding strength) correlated with the observed numerosity estimates. Our results demonstrate a robust radial-tangential anisotropy, suggesting that the topology of spatial vision determines numerosity estimation. We suggest that asymmetries of spatial vision should be taken into account when investigating numerosity estimation.

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Functional Architecture of Eye Position Gain Fields in Visual Association Cortex of Behaving Monkey

Journal of Neurophysiology ◽

10.1152/jn.01179.2002 ◽

2003 ◽

Vol 90 (2) ◽

pp. 1279-1294 ◽

Cited By ~ 28

Author(s):

Ralph M. Siegel ◽

Milena Raffi ◽

Raymond E. Phinney ◽

Jessica A. Turner ◽

Gábor Jandó

Keyword(s):

Cortical Neurons ◽

Visual Information ◽

Parietal Lobe ◽

Association Cortex ◽

Eye Position ◽

Visual Response ◽

Topographic Map ◽

Functional Architecture ◽

Visual Association Cortex ◽

Area 7A

In the behaving monkey, inferior parietal lobe cortical neurons combine visual information with eye position signals. However, an organized topographic map of these neurons' properties has never been demonstrated. Intrinsic optical imaging revealed a functional architecture for the effect of eye position on the visual response to radial optic flow. The map was distributed across two subdivisions of the inferior parietal lobule, area 7a and the dorsal prelunate area, DP. Area 7a contains a representation of the lower eye position gain fields while area DP represents the upper eye position gain fields. Horizontal eye position is represented orthogonal to the vertical eye position across the medial lateral extents of the cortices. Similar topographies were found in three hemispheres of two monkeys; the horizontal and vertical gain field representations were not isotropic with a greater modulation found with the vertical. Monte Carlo methods demonstrated the significance of the maps, and they were verified in part using multiunit recordings. The novel topographic organization of this association cortex area provides a substrate for constructing representations of surrounding space for perception and the guidance of motor behaviors.

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Hemimicropsia in a Patient with a Cavernoma of the Visual Association Cortex: Imaging Analysis Utilizing a New 3D Brain Atlas System and fMRI

NeuroImage ◽

10.1016/s1053-8119(18)31191-1 ◽

1998 ◽

Vol 7 (4) ◽

pp. S358 ◽

Cited By ~ 1

Author(s):

J. Kassubek ◽

M. Otte ◽

T. Wolter ◽

M.W. Greenlee ◽

T. Mergner ◽

...

Keyword(s):

Brain Atlas ◽

Association Cortex ◽

Imaging Analysis ◽

Visual Association Cortex

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The Role of Visual Association Cortex in Associative Memory Formation across Development

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01202 ◽

2018 ◽

Vol 30 (3) ◽

pp. 365-380 ◽

Cited By ~ 13

Author(s):

Maya L. Rosen ◽

Margaret A. Sheridan ◽

Kelly A. Sambrook ◽

Matthew R. Peverill ◽

Andrew N. Meltzoff ◽

...

Keyword(s):

Associative Memory ◽

Visual Processing ◽

Memory Performance ◽

Neural Mechanism ◽

Association Cortex ◽

Associative Memories ◽

Associate Learning ◽

Visual Association Cortex ◽

Age Related

Associative learning underlies the formation of new episodic memories. Associative memory improves across development, and this age-related improvement is supported by the development of the hippocampus and pFC. Recent work, however, additionally suggests a role for visual association cortex in the formation of associative memories. This study investigated the role of category-preferential visual processing regions in associative memory across development using a paired associate learning task in a sample of 56 youths (age 6–19 years). Participants were asked to bind an emotional face with an object while undergoing fMRI scanning. Outside the scanner, participants completed a memory test. We first investigated age-related changes in neural recruitment and found linear age-related increases in activation in lateral occipital cortex and fusiform gyrus, which are involved in visual processing of objects and faces, respectively. Furthermore, greater activation in these visual processing regions was associated with better subsequent memory for pairs over and above the effect of age and of hippocampal and pFC activation on performance. Recruitment of these visual processing regions mediated the association between age and memory performance, over and above the effects of hippocampal activation. Taken together, these findings extend the existing literature to suggest that greater recruitment of category-preferential visual processing regions during encoding of associative memories is a neural mechanism explaining improved memory across development.

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O1-01-08: Pathological evidence of dense Alzheimer lesions in the visual association cortex of cognitively intact elderly subjects

Alzheimer s & Dementia ◽

10.1016/j.jalz.2006.05.041 ◽

2006 ◽

Vol 2 ◽

pp. S10-S10

Author(s):

Ann C. McKee ◽

Rhoda Au ◽

Howard J. Cabral ◽

Neil W. Kowall ◽

Sudha Seshadri ◽

...

Keyword(s):

Association Cortex ◽

Elderly Subjects ◽

Visual Association Cortex ◽

Cognitively Intact

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Processing of color and luminance in visual association cortex

NeuroImage ◽

10.1016/s1053-8119(96)80268-0 ◽

1996 ◽

Vol 3 (3) ◽

pp. S266

Author(s):

Mitchell Brigell ◽

Antonio Strafella ◽

Gastone Celesia

Keyword(s):

Association Cortex ◽

Visual Association Cortex

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Do perceptual asymmetries differ in peripersonal and extrapersonal space?

Journal of the International Neuropsychological Society ◽

10.1017/s135561770999097x ◽

2009 ◽

Vol 16 (1) ◽

pp. 210-214 ◽

Cited By ~ 12

Author(s):

NICOLE A. THOMAS ◽

LORIN J. ELIAS

Keyword(s):

Visual Field ◽

Visual Fields ◽

Leftward Bias ◽

Extrapersonal Space ◽

Within Subjects ◽

Perceptual Asymmetries

AbstractA space-based dissociation has been observed in clinical hemineglect, wherein neglect can be specific to either peripersonal or extrapersonal space. This same dissociation might occur in pseudoneglect, where both space-based and visual field differences have been observed. Upper and bottom visual field differences were examined within-subjects (N = 39), by presenting the greyscales task in both peripersonal and extrapersonal space. The leftward bias was strongest in the bottom visual field; however, no space-based differences were observed. It appears that perceptual biases differ between the upper and bottom visual fields, but this is not related to space-based perceptual biases. (JINS, 2010, 16, 210–214.)

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