The pulvinar is the back end of the thalamus, one on each side: it overhangs the superior colliculi on the roof of the midbrain. At roughly 40% of the thalamus it is the thalamus’s largest nucleus, and it trades signals with every visual area of the cortex. [1][2][3]
The 3D brain needs JavaScript. The text below still says where the pulvinar is and what it does.
Opens cut by a side (sagittal) slice through the thalamus, which holds the pulvinar. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
Not a separate shape in this atlas; lit: the part that holds it. Lit: the whole thalamus, on both sides. The pulvinar is the back part of the thalamus, not a separate organ; BodyParts3D has no shape for it (its only thalamic nuclei are the two geniculate bodies), so the whole thalamus is lit and nothing is drawn at a guessed point. Look at the back end of the lit thalamus. [1][3]
Lit here: the thalamus, the part that holds the pulvinar — see it on its own page.
It lies over the back, upper outer part of the thalamus (the dorsolateral posterior thalamus) and runs along the inner edge of the lateral geniculate nucleus. [3]
Below its back end sit the two superior colliculi of the midbrain, which the pulvinar overhangs; the brachium of the superior colliculus passes between the pulvinar and the medial geniculate body. [2]
It belongs to the lateral group of the thalamus, one of the three groups (anterior, medial, lateral) that the Y-shaped internal medullary lamina divides each thalamus into. [4]
By convention it is split into four nuclei: anterior, inferior, lateral and medial pulvinar. [1]
What it does
Unlike the lateral geniculate nucleus, which takes its main visual input straight from the retina, the pulvinar gets its visual signals mainly from the cortex and the midbrain, and it is connected both ways with all visual cortical areas. [3]
Its input from the superior colliculus seems to matter for starting and correcting quick eye movements (saccades) and for steering visual attention; signals from the superior colliculus must pass through the pulvinar to reach the visual cortex. [1][3]
One proposal is that it gates communication between cortical areas by aligning the timing of their rhythmic activity. [3]
Honest limit: Wikipedia’s summary of the research is that its function is still largely unknown, and much of what is known comes from work in monkeys and cats. [1][3]
Connections
Its lateral and inferior nuclei connect widely with early visual cortical areas; the dorsal part of the lateral nucleus mainly with the posterior parietal cortex; the medial nucleus with the cingulate, posterior parietal, premotor and prefrontal cortex. [1]
Area V2 of the visual cortex receives input from V1 both directly and through the pulvinar. [5]
Other names
Latin pulvinar means a cushioned couch, an armchair lined with pillows; Karl Friedrich Burdach named it in 1817. Plural: pulvinar nuclei. [1]
Size
In humans it makes up roughly 40% of the thalamus, which makes it the largest of its nuclei; it is the largest visual nucleus of the thalamus in primates and cats. [1][3]
The model has no shape for the pulvinar itself, so it is not measured here. The left thalamus that holds it measures about 37 mm front to back, 24 mm top to bottom and 24 mm side to side on this model (the box it fits in, not its volume). [6]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.