New preprint: "The geometry of the neural state space of decisions", work by Mauro Monsalve-Mercado, buff.ly/42wVHD5. Surprising results & predictions! (Thread) We analyze neuropixel population recordings in macaque area LIP during a reaction time, random-dot motion 1/ - ThreadSky

kenmiller.bsky.social • 24 days ago

New preprint: "The geometry of the neural state space of decisions", work by Mauro Monsalve-Mercado, https://buff.ly/42wVHD5. Surprising results & predictions! (Thread) We analyze neuropixel population recordings in macaque area LIP during a reaction time, random-dot motion 1/

Comments

kenmiller.bsky.social•24 days ago

perceptual decision task (monkey saccades to target to indicate choice of 1 of 2 opposite motion directions), recordings (published in https://www.cell.com/neuron/fulltext/S0896-6273(23)00400-2, https://elifesciences.org/reviewed-preprints/90859) by Gabe Stine in Shadlen lab. 2/

kenmiller.bsky.social•24 days ago

We examine the neural manifold - the set of trajectories through the space of neural firing rates during the perceptual decision of the motion direction. The manifold is intrinsically 2D, curved into higher dimensions. One of the 2 dims corresponds to rxn time, ie 3/

kenmiller.bsky.social•24 days ago

different rxn times follow different neural traj's, not the same traj at diff speeds. We examine traj's averaged by rxn time & single trials. Average traj's show a pattern we term "deliberation" and "commitment", w deliberation becoming more pronounced w increasing rxn time. 4/

kenmiller.bsky.social•24 days ago

In deliberation, average traj's of a given rxn time for the 2 choices remain nearby ('distance') & run in similar directions ('cos sim'), & traj's have hi hi-D curvature. In commitment, the 2 traj's sharply diverge, run in roughly orthogonal directions, & have lo curvature. 5/

kenmiller.bsky.social•24 days ago

Single trials show the same 2 phases. During deliberation, traj's have hi tortuosity ('wiggliness'), run less along the direction of the av traj ("resolution dir") and more orthogonal to it both in the manifold ("uncertainty dir") and off-manifold, and have lower speed. 6/

kenmiller.bsky.social•24 days ago

During commitment, trajectories tun straight and quickly in the resolution dir, with tortuoisity and orthogonal excursions strongly suppressed. We think of deliberation as a period of noisy evidence integration, & commitment as internally driven to the decision endpoint. 7/

pessoabrain.bsky.social•24 days ago

"The results highlight the flexible and adaptive recruitment of neurons and the role of intrinsic circuit dynamics in the population implementation of a cognitive task."

That's like music to neuroears!

arielzylberberg.bsky.social•22 days ago

Fun read. Interesting to compare these findings with those of our recent study re-analyzing the same dataset. I suspect that both sets of findings stem from the same underlying principle, yet the approaches and implications are markedly different. https://www.biorxiv.org/content/10.1101/2024.08.15.608159v2

kenmiller.bsky.social•22 days ago

Interesting, look forward to absorbing that, thanks. Would very much appreciate any other thoughts you have on the manuscript.

Comments

Posting Rules

Reply