From the Latin for a ‘cushion’, it is the most caudal nucleus of the thalamus situated over the posterior aspect of the internal capsule. Anatomically, it is distinguished in terms of lateral, inferior, medial and oral sub-nuclei that have (somewhat blurred) topographical connections with association areas in the cerebral cortex: the lateral and inferior pulvinar have wide ranging connections with the visual cortex, the medial pulvinar is similarly wide ranging in its connections with the cingulate gyrus, and posterior parietal and prefrontal cortices, and the oral pulvinar is mainly restricted in its connections to the somatosensory cortex. Consequently, the pulvinar is sometimes referred to as the ‘associative thalamus’. One striking feature of the pulvinar is that it forms indirect cortico-pulvino-cortical circuits, which seem to mimic direct cortico-cortical pathways, a feature termed the ‚’replication principle’. The hodology of the pulvinar is better understood, although not yet completely, than its functions. Functionally, it is thought that it plays a role in attentional mechanisms such as filtering out irrelevant information, a suggestion supported by the fact that lesions to the pulvinar may result in attentional deficits and visual neglect syndromes.
See Attention, Basal ganglia (development), Cingulate gyrus, Dorsal pathway (or stream), Frontal eye fields (FEF), Hodology, Internal capsule, Parietal cortex, Primary visual cortex (V1), Somatosensory cortex, Thalamus