Biology subjects

Akhmetzhanova, A.

Publications and source records attributed to Akhmetzhanova, A..

2 recordsLinked to original sources

bioRxiv2025

Population-level temporal decoding and dynamical structure in frontostriatal circuits during decision making

Perceptual decisions unfold over time, requiring neural circuits to evaluate sensory evidence, track elapsed time, and commit to an action. To investigate how these computations are distributed across corticostriatal circuits, we recorded large-scale neural population activity using Neuropixels probes in the rat frontal orienting field (FOF) and anterior dorsal striatum (ADS) during a free-response auditory change detection task. Both regions exhibited structured, highly dynamic population activity during task performance. Using single-trial population decoding, we found that both FOF and ADS robustly encoded retrospective time from stimulus onset and prospective time preceding the decision report. Using a new approach to analyze temporal encoding to identify the dynamical structure supporting decoding, we found that time encoding could be decomposed into two primary dynamical motifs: monotonic ramp-like trajectories and transient bump-like trajectories. While these modes were similarly expressed during early evidence evaluation, FOF exhibited more pronounced decision-aligned changes near the time of the decision report, possibly reflecting a state transition at commitment. Population geometry analyses further revealed stable low-dimensional subspaces during evidence evaluation that transitioned at decision commitment, with significantly larger subspace changes in FOF than ADS. Together, these results reveal a common dynamical framework during evidence evaluation across corticostriatal circuits, while identifying a selective reorganization of FOF dynamics associated with decision commitment.

neuroscience↗

bioRxiv2025

A parietal grid-like code rotates with cognitive maps but lags rapid behavioral transfer

The neural grid code has been proposed to provide a mechanism for generalization and transfer of relational knowledge between situations enabling rapid adaptation of behavior in novel circumstances. However, to date, very little is known about the dynamics with which grid representations change at context transitions, or how such dynamics relate to downstream behavioral adaptation. Here we tested whether grid representations measured with fMRI rotate to match behavioral goals at context transitions and whether such rotations underlie knowledge transfer. Human participants performed a task that included unsignaled state changes at which the position of multiple target locations abruptly and synchronously rotated by the same degree. After state changes, participants were able to leverage the relative positions of the targets to rapidly infer locations, even novel ones, constituting a form of zero-shot transfer. We observed a cognitive grid-like code in the right posterior parietal cortex with a consistent phase angle that rotated with the relative positions of the targets. However, this rotation was too slow to account for rapid improvements in performance after a state change, and instead these improvements were more closely related to representations of the identity and location of spatial targets in the frontoparietal and orbitofrontal cortex, respectively. Our results highlight the ability of humans to rapidly transfer knowledge and demonstrate that a parietal grid-like code rotates into behaviorally relevant reference frames, but raise questions about the function of such rotations, pointing instead to alternate neural mechanisms for rapid knowledge transfer.

neuroscience↗