Role of the pulvinar in early visual cortical signaling in the macaque.

The pulvinar primarily relays signals from V1 to V2 in macaques, with V1 activity leading pulvinar and pulvinar leading V2, supporting a feedforward communication role.

• Why it matters: Understanding the pulvinar's function is crucial because its interconnectedness with the neocortex suggests it could either broadcast common signals or relay activity between cortical areas, impacting models of visual processing.
• What they did: Researchers recorded neuronal population responses simultaneously in V1, V2, and the pulvinar of anesthetized macaques, analyzing the patterns of activity to test these signaling hypotheses.
• The result: Findings indicate distinct corticopulvinar and corticocortical activity patterns, with a bias toward feedforward signaling, implying the pulvinar's key role in transmitting signals from lower to higher visual cortical areas.