Cortical circuits for the control of attention

Abstract

How are some thoughts favored over others? A wealth of data at the level of single neurons has yielded candidate brain areas and mechanisms for our best-understood model: visual attention. Recent work has naturally evolved toward efforts at a more integrative, network, understanding. It suggests that focusing attention arises from interactions between widespread cortical and subcortical networks that may be regulated via their rhythmic synchronization.

Copyright © 2012 Elsevier Ltd. All rights reserved.

Figures

Figure 1

Summary of interactions between brain regions that give rise to both bottom-up and top-down control of attention.

Figure 2

Local, recurrent, circuitry within posterior cortex that gives rise to automatic selection of salient stimuli, possibly through rhythmic activity. (A) Center-surround structure of LIP receptive fields. (left) A single neuron that responds preferentially to stimuli briefly flashed in its receptive field (purple outline) and is inhibited by surrounding locations (red outline). This effect is consistent across the population (right). Adapted from Falkner et al, 2010 with permission. (B) LIP neurons encode salient objects, regardless of stimulus identity. Adapted from Arcizet et al, 2011 with permission. (C) Electrical stimulation of frontal eye fields induces high-frequency oscillations in parietal cortex. High-frequency oscillations are only increased when FEF is stimulated (bottom row) and the target is in the receptive field of the LIP recording site (left column). Adapted from Premeurer et al, 2012 with permission.

Figure 3

Recurrent cortical circuitry leads to synchronous rhythms and discretization of neural processing. Initial inputs are asynchronous (left). By activating the local circuit this leads to alternating periods of suppression (middle) and activation (right), observed as rhythms in the local population. This process discretizes neural computations and ensures all information is simultaneously available for downstream neurons to act upon. Time flows to the right. Excitatory and inhibitory neurons are orange and red, respectively. Active neurons and connections are saturated colors; inactive neurons and connections are lighter and smaller.