The cortical connections of area V6: an occipito‐parietal network processing visual information

Galletti, Claudio; Gamberini, Michela; Kutz, Dieter F.; Fattori, Patrizia; Luppino, Giuseppe; Matelli, Massimo

doi:10.1046/j.0953-816x.2001.01538.x

Cited by 220 publications

(183 citation statements)

References 51 publications

(160 reference statements)

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“…In fact, the results of the present experiments closely reflect the findings of studies involving injections in area V6 (and/or PO), and in the medial (densely myelinated) part of V3d of macaques (Colby et al, 1988;Felleman et al, 1997;Galletti et al, 2001). Like DM, these areas receive strong projections from V1, which arise primarily in Brodmann's layer IVb (see supplemental Fig.…”

Section: Discussionsupporting

confidence: 74%

“…The main parietal projections originate in the LIP/VIP and MIP regions, although there are smaller inputs from DP/OPt, laterally, and other parietal fields. Connections from ventral areas VP and V4 are robust following lateral injections (in V3d; Felleman et al, 1997), but weak following medial injections [in V6 or PO (Colby et al, 1988;Galletti et al, 2001)]; conversely, projections to MST and other midline cortices are strongest after medial injections. Finally, like V6 and V3d, DM receives extremely sparse projections from the parahippocampal cortex and FST.…”

Section: Discussionmentioning

confidence: 99%

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Connections of the Dorsomedial Visual Area: Pathways for Early Integration of Dorsal and Ventral Streams in Extrastriate Cortex

Palmer²,

et al. 2009

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The dorsomedial area (DM), a subdivision of extrastriate cortex characterized by heavy myelination and relative emphasis on peripheral vision, remains the least understood of the main targets of striate cortex (V1) projections in primates. Here we placed retrograde tracer injections encompassing the full extent of this area in marmoset monkeys, and performed quantitative analyses of the numerical strengths and laminar patterns of its afferent connections. We found that feedforward projections from V1 and from the second visual area (V2) account for over half of the inputs to DM, and that the vast majority of the remaining connections come from other topographically organized visual cortices. Extrastriate projections to DM originate in approximately equal proportions from adjacent medial occipitoparietal areas, from the superior temporal motion-sensitive complex centered on the middle temporal area (MT), and from ventral stream-associated areas. Feedback from the posterior parietal cortex and other association areas accounts for Ͻ10% of the connections. These results do not support the hypothesis that DM is specifically associated with a medial subcircuit of the dorsal stream, important for visuomotor integration. Instead, they suggest an early-stage visual-processing node capable of contributing across cortical streams, much as V1 and V2 do. Thus, although DM may be important for providing visual inputs for guided body movements (which often depend on information contained in peripheral vision), this area is also likely to participate in other functions that require integration across wide expanses of visual space, such as perception of self-motion and contour completion.

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Section: Discussionsupporting

confidence: 74%

Section: Discussionmentioning

confidence: 99%

Connections of the Dorsomedial Visual Area: Pathways for Early Integration of Dorsal and Ventral Streams in Extrastriate Cortex

Palmer²,

et al. 2009

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“…In the visual system, density and laminar profile of the connections between visual areas also differ depending on whether they involve the representation of the central or peripheral visual field (Shipp and Zeki, 1989;Kaas and Morel, 1993;Schall et al 1995;Galletti et al 2001;Palmer and Rosa, 2006). Our connectivity data show that heteromodal connections are also specific to the sensory representation.…”

Section: Specificity Of Heteromodal Connections: Ethological Rolementioning

confidence: 72%

Multisensory anatomical pathways

2009

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In order to interact with the multisensory world that surrounds us, we must integrate various sources of sensory information (vision, hearing, touch. . .). A fundamental question is thus how the brain integrates the separate elements of an object defined by several sensory components to form a unified percept. The superior colliculus was the main model for studying multisensory integration. At the cortical level, until recently, multisensory integration appeared to be a characteristic attributed to high-level association regions. First, we describe recently observed direct cortico-cortical connections between different sensory cortical areas in the non-human primate and discuss the potential role of these connections. Then, we show that the projections between different sensory and motor cortical areas and the thalamus enabled us to highlight the existence of thalamic nuclei that, by their connections, may represent an alternative pathway for information transfer between different sensory and/or motor cortical areas. The thalamus is in position to allow a faster transfer and even an integration of information across modalities. Finally, we discuss the role of these non-specific connections regarding behavioral evidence in the monkey and recent electrophysiological evidence in the primary cortical sensory areas.

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“…V6 + area is known to be highly responsive to optic flow patterns (23). Interestingly, V6 + area has strong connections, first with VIP (43), an area with strong multisensory representations of peripersonal space (44), and second with V6A, a visuomotor area related to reaching and grasping (43,(45)(46)(47). Both areas contain cells that encode visual space in a head-centric reference frame (48,49).…”

Section: Functional Contribution Of V6mentioning

confidence: 99%

Adjacent visual representations of self-motion in different reference frames

Arnoldussen

Goossens²,

Berg³

2011

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

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Recent investigations indicate that retinal motion is not directly available for perception when moving around [Souman JL, et al. (2010) J Vis 10:14], possibly pointing to suppression of retinal speed sensitivity in motion areas. Here, we investigated the distribution of retinocentric and head-centric representations of selfrotation in human lower-tier visual motion areas. Functional MRI responses were measured to a set of visual self-motion stimuli with different levels of simulated gaze and simulated head rotation. A parametric generalized linear model analysis of the blood oxygen level-dependent responses revealed subregions of accessory V3 area, V6 + area, middle temporal area, and medial superior temporal area that were specifically modulated by the speed of the rotational flow relative to the eye and head. Pursuit signals, which link the two reference frames, were also identified in these areas. To our knowledge, these results are the first demonstration of multiple visual representations of self-motion in these areas. The existence of such adjacent representations points to early transformations of the reference frame for visual self-motion signals and a topography by visual reference frame in lower-order motion-sensitive areas. This suggests that visual decisions for action and perception may take into account retinal and head-centric motion signals according to task requirements.hen a child eyeballs the seeker while exposing as little as possible of its head from behind cover, it performs an exquisite piece of eye and head control. Such visually coordinated actions rely on fast and dynamic integration of selfmotion signals from different reference frames (1) to control the rotations of the head, the eye, and other body parts.Motion relative to the eye is directly given on the retina. In the monkey lower-tier visual areas, neurons respond vigorously to such retinal motion (2, 3). Motion relative to the head or other body parts must be derived from visual (4) and nonvisual (5) information on the eye's rotation (6). Many monkey cortical areas also contain neurons that take into account the eye's rotation when responding to visual motion (7-10). Remarkably, a number of recent psychophysical studies have concluded that retinal motion signals are not directly available for perception (11-13), in particular during self-motion (11), whereas headcentric motion signals are.This raises the interesting question how retinal and headcentric representations of visual motion are distributed across the lower-tier visual motion areas. If subjects cannot attend to retinal motion signals, it could indicate that retinal motion sensitivity gives way to head-centric motion signals in higher tier areas, such as the posterior parietal cortex (PPC). Alternatively, signals in both reference frames may be present up to higher visual areas, but not available for certain visual tasks or under certain movement conditions. We investigated if the visual system builds up visual representations of eye-in-space and head-in-space motion. T...

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The cortical connections of area V6: an occipito‐parietal network processing visual information

Cited by 220 publications

References 51 publications

Connections of the Dorsomedial Visual Area: Pathways for Early Integration of Dorsal and Ventral Streams in Extrastriate Cortex

Connections of the Dorsomedial Visual Area: Pathways for Early Integration of Dorsal and Ventral Streams in Extrastriate Cortex

Multisensory anatomical pathways

Adjacent visual representations of self-motion in different reference frames

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