Top-Down Versus Bottom-Up Control of Attention in the Prefrontal and Posterior Parietal Cortices

TLDR

Attention can be focused volitionally by top‑down signals from task demands or automatically by bottom‑up signals from salient stimuli, yet the neural activity of frontal and parietal cortices has not been directly compared. The study aimed to record simultaneous activity from frontal and parietal cortices in monkeys to compare top‑down and bottom‑up attention signals. Simultaneous electrophysiological recordings were performed in monkeys from frontal and parietal cortices. Prefrontal neurons signaled target location first during top‑down attention, whereas parietal neurons did so earlier during bottom‑up attention, with lower‑frequency synchrony dominating top‑down and higher‑frequency synchrony dominating bottom‑up, indicating distinct frontal and sensory origins for the two attention modes.

Abstract

Attention can be focused volitionally by “top-down” signals derived from task demands and automatically by “bottom-up” signals from salient stimuli. The frontal and parietal cortices are involved, but their neural activity has not been directly compared. Therefore, we recorded from them simultaneously in monkeys. Prefrontal neurons reflected the target location first during top-down attention, whereas parietal neurons signaled it earlier during bottom-up attention. Synchrony between frontal and parietal areas was stronger in lower frequencies during top-down attention and in higher frequencies during bottom-up attention. This result indicates that top-down and bottom-up signals arise from the frontal and sensory cortex, respectively, and different modes of attention may emphasize synchrony at different frequencies.