Toward a Unified Theory of Visual Area V4

Roe, Anna Wang; Chelazzi, Leonardo; Connor, Charles E.; Conway, Bevil R.; Fujita, Ichiro; Gallant, Jack L.; Lu, Haidong; Vanduffel, Wim

doi:10.1016/j.neuron.2012.03.011

Cited by 302 publications

(278 citation statements)

References 250 publications

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“…The first is the effect of surround suppression. V4 neurons have powerful nonclassic surrounds (11)(12)(13), and it could be that the task-related selectivity arose from the surround suppression by adjacent objects in the array. Inhibition would also be expected to act later than feed-forward excitation (14).…”

Section: Causes Of the Difference In V4 Responses In The Search And Smentioning

confidence: 99%

Feature attention evokes task-specific pattern selectivity in V4 neurons

Ipata

Gee

Goldberg

2012

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

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A hallmark of visual cortical neurons is their selectivity for stimulus pattern features, such as color, orientation, or shape. In most cases this feature selectivity is hard-wired, with selectivity manifest from the beginning of the response. Here we show that when a task requires that a monkey distinguish between patterns, V4 develops a selectivity for the sought-after pattern, which it does not manifest in a task that does not require the monkey to distinguish between patterns. When a monkey looks for a target object among an array of distractors, V4 neurons become selective for the target ∼50 ms after the visual latency independent of the impending saccade direction. However, when the monkey has to only make a saccade to the spatial location of the same objects without discriminating their pattern, V4 neurons do not distinguish the search target from the distractors. This selectivity for stimulus pattern develops roughly 40 ms after the same neurons’ selectivity for basic pattern features like orientation or color. We suggest that this late-developing selectivity is related to the phenomenon of feature attention and may contribute to the mechanisms by which the brain finds the target in visual search.

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Section: Causes Of the Difference In V4 Responses In The Search And Smentioning

confidence: 99%

Feature attention evokes task-specific pattern selectivity in V4 neurons

Ipata

Gee

Goldberg

2012

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

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“…It is likely that the areas that show a graded spread of attention to the surround are sensitive to figure-ground segmentation and combine multiple cues that reflect the strength of segmentation. In fact, V4 and LOC are well known for their role in figureground segmentations (Altmann et al, 2004;Appelbaum et al, 2006;Chandrasekaran et al, 2007;Cottereau et al, 2011b;Roe et al, 2012); V3a is also sensitive to figure-ground cues generated by depth differences, illusory contours, and segmentation of motion (Mendola et al, 1997;Caplovitz and Tse, 2010;Cottereau et al, 2011b).…”

Section: Resultsmentioning

confidence: 99%

“…A recent review also suggests that the unifying function of V4 circuitry is to enable "selective extraction," whether it is by bottom-up feature-specified shape or by attentionally driven spatial or feature-defined selection (Roe et al, 2012). The same V4 network that mediates figure-ground computation may also enable attentional filtering.…”

Section: The Interaction Of Attention and Segmentationmentioning

confidence: 99%

The Selectivity of Task-Dependent Attention Varies with Surrounding Context

Kim

Verghese

2012

J. Neurosci.

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Attention is thought to operate by enhancing the target of interest and suppressing the surroundings. We hypothesized that the spatial profile of attention depends on the surround's relationship to the target. Using high-density electroencephalographic measurements, we examined the spatial profile of attention to a grating target surrounded by an annular grating that was either coextensive with the target (unsegmented) or appeared segmented from it due to a gap or phase offset. We directly probed the spread of attention from the central target into the surround by flickering the surround and monitoring frequency-tagged steady-state visual-evoked potentials. Observers were required to detect a contrast increment that occurred only on the target. Successful detection of the increment required selecting the target and suppressing the surround, particularly when the target did not readily segment from the surround. The profile of attention was investigated in five visual regions of interest (ROIs) (V1, V4, V3A, lateral occipital complex, and human middle temporal area), mapped in a separate anatomical magnetic resonance imaging scan. We found that in most ROIs, attention to the target generated smaller responses from the surrounding annulus when it was contiguous compared with when it was clearly segmented. This result shows that the profile of attention depends on task demands and on surrounding context; attention is tightly focused when the target region needs to be isolated but loosely focused when the target region is clearly segmented.

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“…Color processing in the brain proceeds along multiple stages, starting from the activity of L, M, and S cones in the retina to color-opponent neurons in the lateral geniculate nucleus and V1 (Conway et al, 2010), to hue maps with color constancy in V2 and V4 (Roe et al, 2012) and finally more "cognitive" aspects in more anterior areas in the temporal cortex. These high-level, cognitive aspects include elements of color knowledge (i.e., knowledge about prototypical object colors, Miceli et al, 2001) and perhaps the possibility of full conscious experience of color (Murphey et al, 2008).…”

Section: Discussionmentioning

confidence: 99%

The anatomy of cerebral achromatopsia: A reappraisal and comparison of two case reports

Bartolomeo

Bachoud‐Lévi

Schotten

2014

Cortex

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Brain damage can produce acquired deficits of color perception, or cerebral achromatopsia. In these patients, lesions tend to overlap on a restricted region in the ventral occipitotemporal cortex, close to the reported locations of the putative V4 complex and to foci of increased BOLD activity related to color perception in normal participants. Unilateral lesions give rise to achromatopsia in the contralateral visual field (hemiachromatopsia). Here we present a partial English translation of the first case report of a hemiachromatopsic patient with detailed anatomical evidence (Madame R, Verrey, 1888), and discuss these results in relation to a more recent case report (Madame D, Bartolomeo et al., 1997) of a patient with two consecutive hemorrhagic lesions in the occipitotemporal regions of the two hemispheres. Strikingly, Madame D developed full-field achromatopsia after the second lesion in the right hemisphere, without having shown any signs of hemiachromatopsia after the first lesion in the left hemisphere. Thanks to the comparison of the reconstructed lesion patterns between the two patients and with the putative location of color-related areas in the human brain, we offer a possible, if speculative, account of this puzzling pattern of anatomo-clinical correlations, based on intra-and inter-hemispheric connectivity.

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Toward a Unified Theory of Visual Area V4

Cited by 302 publications

References 250 publications

Feature attention evokes task-specific pattern selectivity in V4 neurons

Feature attention evokes task-specific pattern selectivity in V4 neurons

The Selectivity of Task-Dependent Attention Varies with Surrounding Context

The anatomy of cerebral achromatopsia: A reappraisal and comparison of two case reports

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