Higher Order Visual Processing in Macaque Extrastriate Cortex

Orban, Guy A.

doi:10.1152/physrev.00008.2007

Cited by 228 publications

(201 citation statements)

References 339 publications

(408 reference statements)

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“…Segregation mechanisms prevent the combination of local motion signals with distinct origins thereby preventing over integration of visual information. Given the fundamental importance of such mechanisms to visual per-ception, the cortical basis of motion integration and segregation has attracted considerable interest, see Born and Bradley [2005] and Orban [2008] for reviews.…”

Section: Introductionmentioning

confidence: 99%

A double dissociation between striate and extrastriate visual cortex for pattern motion perception revealed using rTMS

Thompson

Aaen-Stockdale

Koski

et al. 2009

Human Brain Mapping

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Abstract:The neural mechanisms underlying the integration and segregation of motion signals are often studied using plaid stimuli. These stimuli consist of two spatially coincident dynamic gratings of differing orientations, which are either perceived to move in two unique directions or are integrated by the visual system to elicit the percept of a checkerboard moving in a single direction. Computations pertaining to the motion of the individual component gratings are thought to take place in striate cortex (V1) whereas motion integration is thought to involve neurons in dorsal stream extrastriate visual areas, particularly V5/MT. By combining a psychophysical task that employed plaid stimuli with 1 Hz offline repetitive transcranial magnetic stimulation (rTMS), we demonstrated a double dissociation between striate and extrastriate visual cortex in terms of their contributions to motion integration. rTMS over striate cortex increased coherent motion percepts whereas rTMS over extrastriate cortex had the opposite effect. These effects were robust directly after the stimulation administration and gradually returned to baseline within 15 minutes. This double dissociation is consistent with previous patient data and the recent hypothesis that both coherent and transparent motion percepts are supported by the visual system simultaneously and compete for perceptual dominance.

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Section: Introductionmentioning

confidence: 99%

A double dissociation between striate and extrastriate visual cortex for pattern motion perception revealed using rTMS

Thompson

Aaen-Stockdale

Koski

et al. 2009

Human Brain Mapping

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“…The wide variety of textures we experience enables us to segment objects from backgrounds, perceive object properties, and recognize materials. It is well established that the representation of complex shapes and contours is gradually built up along the ventral visual pathway (2)(3)(4)(5). On the other hand, how textural information is processed in the cortex is largely unknown, although some recent studies have examined the representation of natural textures and surface properties in the macaque ventral visual areas (6)(7)(8)(9)(10)(11).…”

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Image statistics underlying natural texture selectivity of neurons in macaque V4

Okazawa

Tajima

Komatsu

2014

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

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Our daily visual experiences are inevitably linked to recognizing the rich variety of textures. However, how the brain encodes and differentiates a plethora of natural textures remains poorly understood. Here, we show that many neurons in macaque V4 selectively encode sparse combinations of higher-order image statistics to represent natural textures. We systematically explored neural selectivity in a high-dimensional texture space by combining texture synthesis and efficient-sampling techniques. This yielded parameterized models for individual texture-selective neurons. The models provided parsimonious but powerful predictors for each neuron's preferred textures using a sparse combination of image statistics. As a whole population, the neuronal tuning was distributed in a way suitable for categorizing textures and quantitatively predicts human ability to discriminate textures. Together, we suggest that the collective representation of visual image statistics in V4 plays a key role in organizing the natural texture perception.texture perception | material perception | visual area V4 | single-cell recording | image analysis I n the visual world, objects are characterized in part by their shapes, but also by their textures (1). The wide variety of textures we experience enables us to segment objects from backgrounds, perceive object properties, and recognize materials. It is well established that the representation of complex shapes and contours is gradually built up along the ventral visual pathway (2-5). On the other hand, how textural information is processed in the cortex is largely unknown, although some recent studies have examined the representation of natural textures and surface properties in the macaque ventral visual areas (6-11). Because, unlike contours, textures cannot be described based on combinations of edge fragments, we need to consider different underlying cortical processing.In contrast to the limited knowledge available from physiology, computational descriptions of textures have been extensively developed in the fields of psychophysics (12-16) and computer vision (17)(18)(19). In one such description, Portilla and Simoncelli (20) proposed that textures could be represented using an ensemble of summary statistics, including features derived from the luminance histogram and the amplitudes of the outputs of Gabor-like filters, as well as higher-order statistics such as the correlations across the filter outputs (see Fig. 3 for details; hereafter, we call this collection of statistics "PS statistics," using the authors' initials). Portilla and Simoncelli successfully generated new textures that were visually indistinguishable from the originals solely by making their PS statistics identical. Their algorithm is particularly inspiring because PS statistics use filters and computations that share biological properties. It was recently shown, for example, that a version of their synthesis algorithm can generate perceptually indistinguishable visual images (visual metamers) (21) and that naturalisti...

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“…object use understanding | top-down effect | conceptual knowledge C lassic studies on the neural basis of visual perception showed that neurons located in progressively higher cortical visual areas in the macaque monkey show increasingly complex properties (1)(2)(3)(4)(5). On the basis of these findings, it was proposed that neural substrate crucial for visual perception is represented by the higher-order visual areas of the inferior temporal lobe (6)(7)(8).…”

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confidence: 99%

Spatiotemporal dynamics in understanding hand—object interactions

Avanzini

Fabbri-Destro

Campi

et al. 2013

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

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It is generally accepted that visual perception results from the activation of a feed-forward hierarchy of areas, leading to increasingly complex representations. Here we present evidence for a fundamental role of backward projections to the occipitotemporal region for understanding conceptual object properties. The evidence is based on two studies. In the first study, using highdensity EEG, we showed that during the observation of how objects are used there is an early activation of occipital and temporal areas, subsequently reaching the pole of the temporal lobe, and a late reactivation of the visual areas. In the second study, using transcranial magnetic stimulation over the occipital lobe, we showed a clear impairment in the accuracy of recognition of how objects are used during both early activation and, most importantly, late occipital reactivation. These findings represent strong neurophysiological evidence that a top-down mechanism is fundamental for understanding conceptual object properties, and suggest that a similar mechanism might be also present for other higher-order cognitive functions.object use understanding | top-down effect | conceptual knowledge C lassic studies on the neural basis of visual perception showed that neurons located in progressively higher cortical visual areas in the macaque monkey show increasingly complex properties (1-5). On the basis of these findings, it was proposed that neural substrate crucial for visual perception is represented by the higher-order visual areas of the inferior temporal lobe (6-8). Functional MRI (fMRI) data obtained in humans confirmed these findings (9, 10). These data also suggested that the temporal lobe poles are an even higher integration center, where conceptual object properties (e.g., how an object is commonly used) are represented (11-13).Visual information processing has been classically considered to be a feed-forward processing, with perception occurring when the areas at the top of the network become active (6, 14-16). On the other hand, rich anatomical evidence shows that there are massive feedback connections going from higher-order areas back to lower-order areas of the visual ventral stream (17-21). Physiological data also provide evidence for cross-talk between visual areas located at different hierarchical level. In fact transcranial magnetic stimulation (TMS) studies (22-26) reported that single-pulse TMS applied over primary visual areas produces significant perceptual impairment in two distinct time windows: an early one and a late one, relative to the presentation of a visual stimulus. The perception impairment caused by stimulation during the second (late) time window was interpreted as a consequence of an interference with a top-down reactivation of V1 (27,28). A TMS study by Pascual-Leone and Walsh (29) demonstrated that stimulation of area MT/V5 applied 30 ms before the stimulation of V1 affects the activity of this latter region, making participants perceive still rather than moving phosphenes. An analogous cross-talking ef...

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Higher Order Visual Processing in Macaque Extrastriate Cortex

Cited by 228 publications

References 339 publications

A double dissociation between striate and extrastriate visual cortex for pattern motion perception revealed using rTMS

A double dissociation between striate and extrastriate visual cortex for pattern motion perception revealed using rTMS

Image statistics underlying natural texture selectivity of neurons in macaque V4

Spatiotemporal dynamics in understanding hand—object interactions

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