Structure and Function of Visual Area Mt

Born, Richard T.; Bradley, David

doi:10.1146/annurev.neuro.26.041002.131052

Cited by 891 publications

(800 citation statements)

References 192 publications

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“…The contours of the animal are more visible in this image due to the removal of the texture edges by means of surround inhibition. A similar mechanism has been observed in the spatiotemporal domain (Allman et al 1985) and it is known to have several functional implications to motion processing (Born and Bradley 2005). A further aim of the current work is to explore some functional aspects of surround suppression in motion processing using a computational model.…”

supporting

confidence: 60%

Motion detection, noise reduction, texture suppression, and contour enhancement by spatiotemporal Gabor filters with surround inhibition

Petkov

Subramanian

2007

Biol Cybern

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We study the orientation and speed tuning properties of spatiotemporal three-dimensional (3D) Gabor and motion energy filters as models of time-dependent receptive fields of simple and complex cells in the primary visual cortex (V1). We augment the motion energy operator with surround suppression to model the inhibitory effect of stimuli outside the classical receptive field. We show that spatiotemporal integration and surround suppression lead to substantial noise reduction. We propose an effective and straightforward motion detection computation that uses the population code of a set of motion energy filters tuned to different velocities. We also show that surround inhibition leads to suppression of texture and thus improves the visibility of object contours and facilitates figure/ground segregation and the detection and recognition of objects.

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confidence: 60%

Motion detection, noise reduction, texture suppression, and contour enhancement by spatiotemporal Gabor filters with surround inhibition

Petkov

Subramanian

2007

Biol Cybern

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“…MT is one of the primary output pathways for layer six neurons of these early retinotopic regions (Rockland and Van Hoesen 1994;Rockland and Knutson 2000). Neurophysiologically, a role for MT/MST in Wgure/ground assignment for structure-from-motion has been suggested for the past two decades (Allman et al 1985;Olavarria et al 1992;Eifuku and Wurtz 1999;Born 2000;Born and Bradley 2005). Rapid feedback to V1 from areas with large receptive Welds, such as V2 or MT, was proposed in many cases Lamme 1995;Zipser et al 1996;Lee et al 1998;Nothdurft et al 1999Nothdurft et al , 2000Hupé et al 2001;Craft et al 2007).…”

Section: Discussionmentioning

confidence: 99%

Occipital network for figure/ground organization

Likova

Tyler

2008

Exp Brain Res

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This is the accepted version of the paper.This version of the publication may differ from the final published version. Abstract To study the cortical mechanism of Wgure/ ground categorization in the human brain, we employed fMRI and the temporal-asynchrony paradigm. This paradigm is able to eliminate any diVerential activation for local stimulus features, and thus to identify only global perceptual interactions. Strong segmentation of the image into diVerent spatial conWgurations was generated solely from temporal asynchronies between zones of homogeneous dynamic noise. The Wgure/ground conWguration was a single geometric Wgure enclosed in a larger surround region. In a control condition, the Wgure/ground organization was eliminated by segmenting the noise Weld into many identical temporal-asynchrony stripes. The manipulation of the type of perceptual organization triggered dramatic reorganization in the cortical activation pattern. The Wgure/ground conWguration generated suppression of the ground representation (limited to early retinotopic visual cortex, V1 and V2) and strong activation in the motion complex hMT+/ V5+; conversely, both responses were abolished when the Wgure/ground organization was eliminated. These results suggest that Wgure/ground processing is mediated by topdown suppression of the ground representation in the earliest visual areas V1/V2 through a signal arising in the motion complex. We propose a model of a recurrent cortical architecture incorporating suppressive feedback that operates in a topographic manner, forming a Wgure/ground categorization network distinct from that for "pure" scene segmentation and thus underlying the perceptual organization of dynamic scenes into cognitively relevant components. Permanent repository link

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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%

“…Hierarchical two-stage models have been proposed, suggesting that component motion is computed in striate cortex which then leads to pattern motion computation in the extrastriate middle temporal area (area MT, the human homologue of which is known as V5) [Movshon et al, 1985;Rust et al, 2006;Simoncelli and Heeger, 1998]. MT is further along the motion processing hierarchy than V1 and is known to be highly specialized for motion perception [Born and Bradley, 2005]. Evidence for such a processing hierarchy was provided by studies demonstrating a lack of pattern motion responses in V1 [Movshon and Newsome, 1996] and a subset of neurons ( 15%) that were pattern selective in MT [Movshon et al, 1985].…”

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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Structure and Function of Visual Area Mt

Cited by 891 publications

References 192 publications

Motion detection, noise reduction, texture suppression, and contour enhancement by spatiotemporal Gabor filters with surround inhibition

Motion detection, noise reduction, texture suppression, and contour enhancement by spatiotemporal Gabor filters with surround inhibition

Occipital network for figure/ground organization

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

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