Pulvinar contributions to the dorsal and ventral streams of visual processing in primates

Abstract

The visual pulvinar is part of the dorsal thalamus, and in primates it is especially well developed. Recently, our understanding of how the visual pulvinar is subdivided into nuclei has greatly improved as a number of histological procedures have revealed marked architectonic differences within the pulvinar complex. At the same time, there have been unparalleled advances in understanding of how visual cortex of primates is subdivided into areas and how these areas interconnect. In addition, considerable evidence supports the view that the hierarchy of interconnected visual areas is divided into two major processing streams, a ventral stream for object vision, and a dorsal stream for visually guided actions. In this review, we present evidence that a subset of medial nuclei in the inferior pulvinar function predominantly as a subcortical component of the dorsal stream while the most lateral nucleus of the inferior pulvinar and the adjoining ventrolateral nucleus of the lateral pulvinar are more devoted to the ventral stream of cortical processing. These nuclei provide cortico-pulvinarcortical interactions that spread information across areas within streams, as well as information relayed from the superior colliculus via inferior pulvinar nuclei to largely dorsal stream areas.

Impaired attentional selection following lesions to human pulvinar: Evidence for homology between human and monkey

“…These psychophysical data from human observers with discrete pulvinar lesions lend strong support to speculations that the pulvinar plays a role in integrating fronto-parietal attentional control signals within visual processing areas (13,14,20). The patients were impaired in discriminating target features, but only when targets were accompanied by salient distracters.…”

“…Ventral pulvinar [PU(v)], conversely, which includes cell populations within inferior, lateral and medial subnuclei, exhibits reciprocal connections with successive occipitotemporal cortical areas along the ventral processing stream, and contains several topographic maps of the contralateral visual field (13,(17)(18)(19)(20). Although there are few direct connections between PU(d) and PU(v), attentional control areas such as the frontal eye fields (FEF) and lateral intraparietal area (LIP) have strong connections with the superior colliculus (SC), which subsequently projects to PU(v) (13,14).…”

“…Specifically, early visual areas are connected with the rostrolateral pole of the pulvinar nucleus, whereas neurons in progressively more anterior temporal areas show overlapping patterns of connectivity with more caudomedial regions (16,(19)(20)(21).…”

Voxel-Based Morphometry and Diffusion Tensor Imaging of the Optic Pathway in Primary Open-Angle Glaucoma: A Preliminary Study

“…color, and orientation selectivity). 27 Thus, the neurogenerative changes observed in the present study may be related to glaucoma.…”

Signal processing in the tectothalamic pathway.

“…In simian primates, retrograde tracing experiments have shown that the tectorecipient subdivisions PIp and PIcm primarily project to cortical areas surrounding the middle temporal area (MT), which can be identified by dense myelin staining (Cusick et al 1993;Stepniewska et al 1999Stepniewska et al ,2000Kaas and Lyon 2007). Furthermore, pulvinar neurons which can be orthodromically activated from the SC are intermingled with cells that can be antidromically activated from area MT (Berman and Wurtz 2008).…”