Color Signals in Human Motion-Selective Cortex

Wandell, Brian A.; Poirson, Allen; Newsome, William T.; Baseler, Heidi A.; Boynton, Geoffrey M.; Huk, Alexander C.; Gandhi, Sunil; Sharpe, Lindsay T.

doi:10.1016/s0896-6273(00)81037-5

Cited by 121 publications

(91 citation statements)

References 36 publications

(7 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Analogous contingent after-effects have been used extensively to examine the tuning of low-level mechanisms. For example, in the McCollough effect, adaptation to an alternating green-black horizontal grating and red-black vertical grating produces an orientation-specific adaptation effect causing horizontal gratings to appear redder and vertical gratings to appear greener (30)(31)(32)(33)(34)(35). Fig.…”

Section: Resultsmentioning

confidence: 99%

Selectivity for the configural cues that identify the gender, ethnicity, and identity of faces in human cortex

Ciaramitaro

Anstis

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We used psychophysical and functional MRI (fMRI) adaptation to examine how and where the visual configural cues underlying identification of facial ethnicity, gender, and identity are processed. We found that the cortical regions showing selectivity to these cues are distributed widely across the inferior occipital cortex, fusiform areas, and the cingulate gyrus. These regions were not colocalized with areas activated by traditional face area localizer scans. Traditional face area localizer scans isolate regions defined by stronger fMRI responses to a random series of face images than to a series of non-face images. Because these scans present a random assortment of face images, they presumably produce the strongest responses within regions containing neurons that are face-sensitive but not highly tuned for face type. These areas might be expected to show only weak selective adaptation effects. In contrast, the largest responses to our selective adaptation paradigm would be expected within areas containing more selectively tuned neurons that might be expected to show only a sparse collective response to a series of random faces. Many aspects of face processing (e.g., prosopagnosia, recognition, and configural vs. featural processing) are likely to rely heavily on regions containing high proportions of neurons that show selective tuning for faces.

show abstract

Section: Resultsmentioning

confidence: 99%

Selectivity for the configural cues that identify the gender, ethnicity, and identity of faces in human cortex

Ciaramitaro

Anstis

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Our results suggest that a blue-off pathway, like the blue-on pathway (6, 7), thus could contribute directly to S-cone-mediated motion processing (38,39) as well as to cortical pathways for color vision.…”

Section: Discussionmentioning

confidence: 73%

Geniculocortical relay of blue-off signals in the primate visual system

Szmajda

Buzás

FitzGibbon

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A fundamental dichotomy in the subcortical visual system exists between on-and off-type neurons, which respectively signal increases and decreases of light intensity in the visual environment. In primates, signals for red-green color vision are carried by both on-and off-type neurons in the parvocellular division of the subcortical pathway. It is thought that on-type signals for blueyellow color vision are carried by cells in a distinct, diffusely projecting (koniocellular) pathway, but the pathway taken by blue-off signals is not known. Here, we measured blue-off responses in the subcortical visual pathway of marmoset monkeys. We found that the cells exhibiting blue-off responses are largely segregated to the koniocellular pathway. The blue-off cells show relatively large receptive fields, sluggish responses to maintained contrast, little sign of an inhibitory receptive-field surround mechanism, and negligible functional input from an intrinsic (melanopsin-based) phototransductive mechanism. These properties are consistent with input from koniocellular or ''W-like'' ganglion cells in the retina and suggest that blue-off cells, as previously shown for blue-on cells, could contribute to cortical mechanisms for visual perception via the koniocellular pathway.color vision ͉ short-wavelength-sensitive cones ͉ blue cones ͉ koniocellular pathway ͉ lateral geniculate nucleus T his study addresses the properties of sensory afferent pathways for primate color vision. Chromatic information is transmitted from the retina to the cortex via the lateral geniculate nucleus (LGN). Many neurons in the LGN show ''cone opponent'' responses: they are activated by a restricted range of wavelengths in the visible spectrum and inhibited by others. In trichromatic primates, the dorsal (parvocellular) layers of the LGN are dominated by neurons that show red-green cone opponent responses, as a result of antagonistic inputs arising in medium-wavelength-sensitive (M or ''green'') and longwavelength-sensitive (L or ''red'') cones. A smaller proportion of neurons in the retina and LGN shows blue-on responses, as a result of excitatory input arising in short-wavelength-sensitive (S) cones (1-5). Blue-on ganglion cells in the retina show a distinct bistratified morphology (5), and blue-on signals reach the visual cortex via the koniocellular/intercalated layers of the LGN (6, 7). Unlike cells in the parvocellular (PC) and ventral (magnocellular) layers, the constituent cells of koniocellular pathways show diverse functional properties and widespread cortical terminations and are considered to have arisen early in the evolutionary history of the visual system (7-9). The blue-on koniocellular cells thus have been considered as part of a primordial pathway for color vision (10). By contrast, the divergence of M and L cones to yield red-green signals in PC pathway cells occurred relatively recently (Ϸ15 million years ago) in the evolution of the primate visual system (11,12).Receptive fields receiving off-type signals from S cones (''blue-off'') r...

show abstract

“…For example, one can compare spike-rate equivalent stimulus contrast values with BESC values. Notably, by using the stimulus-referred procedure, the neuroimaging, electrophysiological, and behavioral experiments can provide converging evidences for neural models (Dougherty et al, 1999;Seidemann et al, 1999;Wandell et al, 1999).…”

Section: Stimulus-referred Proceduresmentioning

confidence: 99%

“…There is consistency between the motion selectivity of MT neurons and behavior (Britten et al, 1992). Conversely, MT receives weak S-cone signals (Seidemann et al, 1999;Wandell et al, 1999), and its receptive fields are relatively large (Albright and Desimone, 1987), making the circuitry poorly suited for detailed pattern vision or color. These observations support the theory that MT is specialized for motion processing.…”

Section: Introductionmentioning

confidence: 99%

Specializations for Chromatic and Temporal Signals in Human Visual Cortex

Liu¹,

Wandell²

2005

J. Neurosci.

110

View full text Add to dashboard Cite

Neurological case studies and qualitative measurements suggest that regions within human extrastriate cortex are specialized for different perceptual functions, including color. However, there are few quantitative measurements of human extrastriate color specializations. We studied the chromatic and temporal responses in several different clusters of human visual field maps using functional magnetic resonance imaging. Contrast response functions were measured for luminance [(L ϩ M)-cone], red-green [(L Ϫ M)-cone] and blueyellow (S-cone) modulations at various temporal frequencies. In primary visual cortex (V1), temporal responsivities to luminance and red-green modulations are approximately constant up to 10 Hz, but responsivities to blue-yellow modulations decrease significantly. In ventral occipital cortex (VO), all colors elicit strong responses, and, for each color, low temporal frequency modulations are more effective than high temporal frequency modulations. Hence, VO represents the full range of color information but does not respond well to rapid modulations. Conversely, in human motion-selective cortex (MTϩ) and V3A, blue-yellow modulations elicit very weak responses, whereas luminance and red-green high temporal frequency modulations are equally or more effective than low temporal frequency modulations. Hence, these dorsal occipital regions respond well to rapid modulations, but not all color information is represented. Similar to human motion perception, MTϩ and V3A respond powerfully to all temporal frequencies but only to some colors. Similar to human color perception, VO responds powerfully to all colors but only to relatively low temporal frequencies.

show abstract

Color Signals in Human Motion-Selective Cortex

Cited by 121 publications

References 36 publications

Selectivity for the configural cues that identify the gender, ethnicity, and identity of faces in human cortex

Selectivity for the configural cues that identify the gender, ethnicity, and identity of faces in human cortex

Geniculocortical relay of blue-off signals in the primate visual system

Specializations for Chromatic and Temporal Signals in Human Visual Cortex

Contact Info

Product

Resources

About