Topographical organization of cortical afferents to extrastriate visual area PO in the macaque: A dual tracer study

Abstract

We have examined the origin and topography of cortical projections to area PO, an extrastriate visual area located in the parieto-occipital sulcus of the macaque. Distinguishable retrograde fluorescent tracers were injected into area PO at separate retinotopic loci identified by single-neuron recording. The results indicate that area PO receives retinotopically organized inputs from visual areas V1, V2, V3, V4, and MT. In each of these areas the projection to PO arises from the representation of the periphery of the visual field. This finding is consistent with neurophysiological data indicating that the representation of the periphery is emphasized in PO. Additional projections arise from area MST, the frontal eye fields, and several divisions of parietal cortex, including four zones within the intraparietal sulcus and a region on the medial dorsal surface of the hemisphere (MDP). On the basis of the laminar distribution of labeled cells we conclude that area PO receives an ascending input from V1, V2, and V3 and receives descending or lateral inputs from all other areas. Thus, area PO is at approximately the same level in the hierarchy of visual areas as areas V4 and MT. Area PO is connected both directly and indirectly, via MT and MST, to parietal cortex. Within parietal cortex, area PO is linked to particular regions of the intraparietal sulcus including VIP and LIP and two newly recognized zones termed here MIP and PIP. The wealth of connections with parietal cortex suggests that area PO provides a relatively direct route over which information concerning the visual field periphery can be transmitted from striate and prestriate cortex to parietal cortex. In contrast, area PO has few links with areas projecting to inferior temporal cortex. The pattern of connections revealed in this study is consistent with the view that area PO is primarily involved in visuospatial functioning.

Frames of Reference for Perception and Action in the Human Visual System

“…These and other findings (for review, see (27)) suggest that visuomotor systems may be more sensitive to stimuli in the visual periphery than the perceptual systems mediating our experience of the visual world beyond the fovea. These behavioural observations in humans are consistent with anatomical and electrophysiological studies in the monkey showing that areas in the dorsal stream receive extensive inputs from the peripheral visual fields while inputs to the ventral stream are largely from more central regions of the visual field (for review, see (2,12)). The difference in representation of the visual field might explain why the visual control of grasping movements directed at targets in the visual periphery is so much more reliable than perceptual judgements about those same objects; in short, the dorsal action is simply better connected with the visual periphery than the ventral perception system.…”

Projection from Visual Areas V2 and Prostriata to Caudal Auditory Cortex in the Monkey

“…For example, peripheral but not central representations of areas V1 and V2 are connected with numerous dorsal visual stream areas in temporal and parietal cortex (Colby et al 1988;Gattass et al 1990;Nakamura et al 1993;Gattass et al 1997;Ungerleider et al 2008). Area prostriata is reported to have visual function (Sousa et al 1991;Rosa et al 1997) and appears to preferentially connect with the peripheral representation of areas V1, V2, and MT (Palmer and Rosa 2006).…”

Implementation of Spatial Transformation Rules for Goal-Directed Reaching via Gain Modulation in Monkey Parietal and Premotor Cortex

“…If the idea of gain modulation for space-context integration holds true, then spatially selective neurons in primate cortical sensorimotor areas, like the parietal reach region (PRR) and the dorsal premotor cortex (PMd), should be upregulated and downregulated by the behavioral context. Spatial sensory information presumably reaches the frontoparietal sensorimotor network via the posterior parietal cortex (Colby et al, 1988;Blatt et al, 1990;Marconi et al, 2001). Associative goal selection criteria or arbitrary transformation rules are believed to exert their influence on motor planning via prefrontal and premotor areas (Rushworth et al, 1997;Wise and Murray, 2000;Toni et al, 2001;Wallis and Miller, 2003).…”