scholarly journals Visual field maps and color signals in human ventral occipital cortex

2010 ◽  
Vol 2 (7) ◽  
pp. 549-549
Author(s):  
A. A. Brewer ◽  
A. R. Wade ◽  
B. A. Wandell
Keyword(s):  
Visual Field ◽  
Occipital Cortex ◽  
Visual Field Maps ◽  
Color Signals

scholarly journals Erratum: Corrigendum: Visual field maps and stimulus selectivity in human ventral occipital cortex

2005 ◽  
Vol 8 (10) ◽  
pp. 1411-1411 ◽  
Author(s):  
Alyssa A Brewer ◽  
Junjie Liu ◽  
Alex R Wade ◽  
Brian A Wandell
Keyword(s):  
Visual Field ◽  
Occipital Cortex ◽  
Visual Field Maps

scholarly journals Visual Field Maps, Population Receptive Field Sizes, and Visual Field Coverage in the Human MT+ Complex

2009 ◽  
Vol 102 (5) ◽  
pp. 2704-2718 ◽  
Author(s):  
Kaoru Amano ◽  
Brian A. Wandell ◽  
Serge O. Dumoulin
Keyword(s):  
Visual Field ◽  
Receptive Field ◽  
Occipital Cortex ◽  
Progressive Increase ◽  
Human Motion ◽  
Complete Characterization ◽  
Lower Visual Field ◽  
Vertical Meridian ◽  
Visual Field Maps

Human neuroimaging experiments typically localize motion-selective cortex (MT+) by contrasting responses to stationary and moving stimuli. It has long been suspected that MT+, located on the lateral surface at the temporal–occipital (TO) boundary, contains several distinct visual field maps, although only one coarse map has been measured. Using a novel functional MRI model–based method we identified two maps—TO-1 and TO-2—and measured population receptive field (pRF) sizes within these maps. The angular representation of the first map, TO-1, has a lower vertical meridian on its posterior side at the boundary with the lateral–occipital cortex (i.e., the LO-2 portion). The angular representation continues through horizontal to the upper vertical meridian at the boundary with the second map, TO-2. The TO-2 angle map reverses from upper to lower visual field at increasingly anterior positions. The TO maps share a parallel eccentricity map in which center-to-periphery is represented in the ventral-to-dorsal direction; both maps have an expanded foveal representation. There is a progressive increase in the pRF size from V1/2/3 to LO-1/2 and TO-1/2, with the largest pRF sizes in TO-2. Further, within each map the pRF size increases as a function of eccentricity. The visual field coverage of both maps extends into the ipsilateral visual field, with larger sensitivity to peripheral ipsilateral stimuli in TO-2 than that in TO-1. The TO maps provide a functional segmentation of human motion-sensitive cortex that enables a more complete characterization of processing in human motion-selective cortex.

Visual field maps and stimulus selectivity in human ventral occipital cortex

2005 ◽  
Vol 8 (8) ◽  
pp. 1102-1109 ◽  
Author(s):  
Alyssa A Brewer ◽  
Junjie Liu ◽  
Alex R Wade ◽  
Brian A Wandell
Keyword(s):  
Visual Field ◽  
Occipital Cortex ◽  
Visual Field Maps

Equal Degrees of Object Selectivity for Upper and Lower Visual Field Stimuli

2010 ◽  
Vol 104 (4) ◽  
pp. 2075-2081 ◽  
Author(s):  
Lars Strother ◽  
Adrian Aldcroft ◽  
Cheryl Lavell ◽  
Tutis Vilis
Keyword(s):  
Visual Field ◽  
Occipital Cortex ◽  
Recognition System ◽  
Blood Oxygen Level Dependent ◽  
Lower Visual Field ◽  
Blood Oxygen Level ◽  
Visual Areas ◽  
Bold Responses ◽  
Cortical Regions ◽  
Lateral Occipital Cortex

Functional MRI (fMRI) studies of the human object recognition system commonly identify object-selective cortical regions by comparing blood oxygen level–dependent (BOLD) responses to objects versus those to scrambled objects. Object selectivity distinguishes human lateral occipital cortex (LO) from earlier visual areas. Recent studies suggest that, in addition to being object selective, LO is retinotopically organized; LO represents both object and location information. Although LO responses to objects have been shown to depend on location, it is not known whether responses to scrambled objects vary similarly. This is important because it would suggest that the degree of object selectivity in LO does not vary with retinal stimulus position. We used a conventional functional localizer to identify human visual area LO by comparing BOLD responses to objects versus scrambled objects presented to either the upper (UVF) or lower (LVF) visual field. In agreement with recent findings, we found evidence of position-dependent responses to objects. However, we observed the same degree of position dependence for scrambled objects and thus object selectivity did not differ for UVF and LVF stimuli. We conclude that, in terms of BOLD response, LO discriminates objects from non-objects equally well in either visual field location, despite stronger responses to objects in the LVF.

scholarly journals Visual field map clusters in human cortex

2005 ◽  
Vol 360 (1456) ◽  
pp. 693-707 ◽  
Author(s):  
Brian A Wandell ◽  
Alyssa A Brewer ◽  
Robert F Dougherty
Keyword(s):  
Visual Field ◽  
Functional Mri ◽  
Spatial Organization ◽  
Perceptual Processing ◽  
Large Set ◽  
Human Cortex ◽  
General Properties ◽  
Visual Field Maps

We describe the location and general properties of nine human visual field maps. The cortical location of each map, as well as many examples of the eccentricity and angular representations within these maps, are shown in a series of images that summarize a large set of functional MRI data. The organization and properties of these maps are compared and contrasted with descriptions by other investigators. We hypothesize that the human visual field maps are arranged in several clusters, each comprising a group of maps that share a common foveal representation and semicircular eccentricity map. The spatial organization of these clusters suggests that the perceptual processing within each cluster serves related functions.

Abnormal visual field maps in human cortex: A mini-review and a case report

Cortex ◽  
2014 ◽  
Vol 56 ◽  
pp. 14-25 ◽  
Author(s):  
Koen V. Haak ◽  
Dave R.M. Langers ◽  
Remco Renken ◽  
Pim van Dijk ◽  
Johannes Borgstein ◽  
...  
Keyword(s):  
Case Report ◽  
Visual Field ◽  
Human Cortex ◽  
Visual Field Maps ◽  
Abnormal Visual

The pupillary light reflex in normal and innate microstrabismic cats, II: Retinal and cortical input to the nucleus praetectalis olivaris

1989 ◽  
Vol 3 (2) ◽  
pp. 139-153 ◽  
Author(s):  
C. Distler ◽  
K.-P. Hoffmann
Keyword(s):  
Electrical Stimulation ◽  
Visual Field ◽  
Ganglion Cells ◽  
Occipital Cortex ◽  
Pupillary Light Reflex ◽  
Binocular Summation ◽  
Cortical Input ◽  
Light Reflex ◽  
Pupillary Light ◽  
Upper Visual Field

AbstractThe anatomical substrate of the pupillary light reflex was investigated in normal and innate microstrabismic cats using anatomical methods as well as electrical stimulation. The bilateral retinal input to the nucleus praetectalis olivaris (NPO), the pretectal relay station in the subcortical pupilloconstrictor pathway, was identified to come from the ventral retina where the upper visual field is represented. Orthodromic electrical stimulation revealed that retinal information is transmitted to on-tonic neurons in the NPO mainly via slowly conducting axons probably originating from W- and X-type retinal ganglion cells.For the first time, a direct cortical input to on-tonic neurons in the NPO could be demonstrated. This cortical input originates from caudolateral parts of the occipital cortex. Putative input structures are those subdivisions of areas 19 and 20a where the upper part of the visual field is represented.A direct, predominantly contralateral projection with a weak ipsilateral component from NPO to the nucleus of Edinger-Westphal, and an interhemispheric connection between the NPOs could be demonstrated. With respect to the anatomical connections as described in this study, no differences between normal and innate microstrabismic cats could be found.The results are discussed with respect to the binocular summation of the pupillary light reflex and its reduction in subjects with impaired binocular vision.

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