Geometry of neural dynamics along the cortical attractor landscape reflects changes in attention.

Large-scale brain activity reflects changes in attention. To understand how, we tested a hypothesis that the geometry of neural dynamics on the cortical attractor landscape, or movement along its "hills and valleys", reflects attentional states. A dynamical systems model separating intrinsic dynamics from stimulus-driven influences was fit to fMRI data collected during rest, tasks, and movie-watching. Model simulations revealed a set of attractors aligned with canonical functional brain networks. The speed and direction of neural trajectories toward these attractors varied systematically with attentional states over time and across contexts. When participants were paying attention to effortful tasks, neural dynamics converged fast and directly toward a task-relevant attractor. In contrast, when participants were engaged in sitcom episodes, neural dynamics occupied a flatter region of the landscape, directed away from attractors. These findings demonstrate that while attractor locations are largely determined by cortical organization, the geometry of neural dynamics changes systematically across attentional states and contexts.