Impairments in Spatial Generalization of Visual Skills After V4 and TEO Lesions in Macaques (Macaca mulatta).

Weerd, Peter De; Desimone, Robert; Ungerleider, Leslie G.

doi:10.1037/0735-7044.117.6.1441

Cited by 12 publications

(9 citation statements)

References 64 publications

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“…For example, studies of rivalry may have found closer correlations between neuronal activity and perceptual reports in later visual cortex because later stages play a special role in rivalry. Because lesions restricted to higher stages in the cortical hierarchy do not affect performance on simple discrimination tasks [37,38], it is possible that tasks involving simple visual attributes or those involving precise spatial localization, such as hyperacuity, might reveal stronger correlations between behavior and neuronal activity in intermediate or early areas.…”

Section: Discussionmentioning

confidence: 99%

Behavioral Detection of Electrical Microstimulation in Different Cortical Visual Areas

2007

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The extent to which areas in the visual cerebral cortex differ in their ability to support perceptions has been the subject of considerable speculation. Experiments examining the activity of individual neurons have suggested that activity in later stages of the visual cortex is more closely linked to perception than that in earlier stages [1-9]. In contrast, results from functional imaging, transcranial magnetic stimulation, and lesion studies have been interpreted as showing that earlier stages are more closely coupled to perception [10-15]. We examined whether neuronal activity in early and later stages differs in its ability to support detectable signals by measuring behavioral thresholds for detecting electrical microstimulation in different cortical areas in two monkeys. By training the animals to perform a two-alternative temporal forced-choice task, we obtained criterion-free thresholds from five visual areas--V1, V2, V3A, MT, and the inferotemporal cortex. Every site tested yielded a reliable threshold. Thresholds varied little within and between visual areas, rising gradually from early to later stages. We similarly found no systematic differences in the slopes of the psychometric detection functions from different areas. These results suggest that neuronal signals of similar magnitude evoked in any part of visual cortex can generate percepts.

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Section: Discussionmentioning

confidence: 99%

Behavioral Detection of Electrical Microstimulation in Different Cortical Visual Areas

2007

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“…Human studies relied on the rare observation of neurological patients with circumscribed lesions to V4 (Rizzo et al, 1992; Gallant et al, 2000; Merigan et al, 1997). These lesion studies showed that lesions to human V4 have effects similar to V4 lesions in nonhuman primates (De Weerd et al, 1996, 2003; Merigan, 1996, 2000; Merigan and Pham, 1998; Schiller, 1995) and that human V4 lesions affect curvature discrimination (Gallant et al, 2000). More recent fMRI studies suggest that area V4 in humans is activated preferentially by concentric and radial gratings (Wilkinson et al, 2000) and textures (Dumoulin and Hess, 2007).…”

Section: V4 Is a Midtier Feature Representation Area: Computatiomentioning

confidence: 95%

Toward a Unified Theory of Visual Area V4

Roe

Chelazzi

Connor

et al. 2012

Neuron

319

250

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Visual area V4 is a midtier cortical area in the ventral visual pathway. It is crucial for visual object recognition and has been a focus of many studies on visual attention. However, there is no unifying view of V4’s role in visual processing. Neither is there an understanding of how its role in feature processing interfaces with its role in visual attention. This review captures our current knowledge of V4, largely derived from electrophysiological and imaging studies in the macaque monkey. Based on recent discovery of functionally specific domains in V4, we propose that the unifying function of V4 circuitry is to enable selective extraction of specific functional domain-based networks, whether it be by bottom-up specification of object features or by top-down attentionally driven selection.

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“… ** Postoperative experiments, during which additional data were collected that are not part of the present paper. Specifically, during postoperative months 1, 4 and 5 in monkey M1, and month 9 in monkey M2, the spatial generalization of shape and colour discriminations was tested in lesion‐affected and normal quadrants (De Weerd et al ., 2003). During months 6, 12 and 19 in M1, and months 11 and 12 in M2, manipulations of grating and distracter contrast, and target‐distracter distance were carried out, as well as a target detection experiment and an acuity measurement (De Weerd et al ., 1999; acuity data summarized in Table 3).…”

Section: Testing Historymentioning

confidence: 99%

Generalized deficits in visual selective attention after V4 and TEO lesions in macaques

Weerd¹,

Desimone²,

Ungerleider³

2003

Eur J of Neuroscience

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To test the role of areas V4 and TEO in the attentional filtering of distracting information, we studied the effects of lesions in these areas, in monkeys discriminating target stimuli surrounded by irrelevant distracters. The lesions were restricted, such that a single visual field quadrant was affected by a V4 lesion alone, a TEO lesion alone, or a combined lesion in V4 and TEO, while one quadrant served as a normal control. The monkeys fixated a spot while discriminating the orientation, colour or motion of target stimuli presented extrafoveally in each quadrant. When the target was presented alone, discrimination deficits in the quadrants affected by the lesions were generally small. However, these deficits were substantially increased by surrounding the target with luminance, colour or motion distracters. The discrimination of target orientation was more impaired than the discrimination of target colour or motion, irrespective of distracter type. The discrimination of target motion was strongly affected only by motion distracters. The magnitude of the impairments increased with distracter strength and with the extent to which the distracters conveyed information conflicting with the target. Deficits in the quadrant affected by combined V4 and TEO lesions were twice as large as those in quadrants affected by V4 or TEO lesions alone. The results suggest that in the absence of V4 and TEO, information from both relevant and irrelevant stimuli is 'averaged' together across several different feature domains, impairing the discrimination of the relevant target features. The results suggest a broad role of V4 and TEO in visual selective attention.

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Impairments in Spatial Generalization of Visual Skills After V4 and TEO Lesions in Macaques (Macaca mulatta).

Cited by 12 publications

References 64 publications

Behavioral Detection of Electrical Microstimulation in Different Cortical Visual Areas

Behavioral Detection of Electrical Microstimulation in Different Cortical Visual Areas

Toward a Unified Theory of Visual Area V4

Generalized deficits in visual selective attention after V4 and TEO lesions in macaques

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