The pulvinar nuclei are a collection of nuclei

Nucleus (neuroanatomy)

In neuroanatomy, a nucleus is a brain structure consisting of a relatively compact cluster of neurons. It is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. In anatomical sections, a nucleus shows up...

 located in the pulvinar thalamus

Thalamus

The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

. The pulvinar part is the most posterior region of the thalamus.

The pulvinar is usually grouped as one of the lateral thalamic nuclei. The word is derived from the Latin pulvinus for "cushion". In Ancient Roman religion a pulvinar was an "empty throne" or cushioned couch for occupation by a deity.

Divisions

It is conventionally divided into dorsal, inferior, lateral, and medial subnuclei.

• The lateral and inferior pulvinar have widespread connections with visual cortical
  Visual cortex
  The visual cortex of the brain is the part of the cerebral cortex responsible for processing visual information. It is located in the occipital lobe, in the back of the brain....
  
   association areas.

• The dorsal pulvinar predominantly has connections with somatosensory cortical association areas.

• The medial pulvinar has widespread connections with cingulate, posterior parietal, and prefrontal cortical areas.

• The pulvinar also has input from the superior colliculus
  Superior colliculus
  The optic tectum or simply tectum is a paired structure that forms a major component of the vertebrate midbrain. In mammals this structure is more commonly called the superior colliculus , but, even in mammals, the adjective tectal is commonly used. The tectum is a layered structure, with a...
  
   that influences pulvinar output to visual association cortex, which seems to be important in regulating visual attention

Species variation

The pulvinar varies in importance in different animals: it is virtually nonexistent in the rat, and grouped as the lateral posterior-pulvinar complex" with the lateral posterior thalamic nucleus due to its small size in cats. In humans it makes up roughly 40% of the thalamus making it the largest of its nuclei.

Pathology

Lesions of the pulvinar can result in neglect syndromes and attentional deficits.