Biology subjects

Flouty, O.

Publications and source records attributed to Flouty, O..

2 recordsLinked to original sources

bioRxiv2024

Distinct mechanisms of visual and sound adaptation in the cat visual cortex

Sensory areas exhibit modular selectivity to stimuli, but they can also respond to features outside of their basic modality. Several studies have shown cross-modal plastic modifications between visual and auditory cortices; however, the exact mechanisms of these modifications are yet not completely known. To this aim, we investigated the effect of 12 minutes of visual vs. sound adaptation [forceful application of a non-optimal stimulus to a neuron(s) under observation] on the infra- and supra-granular primary visual neurons (V1) of the cat (Felis catus). Previous reports showed that both protocols induced orientation tuning shifts, but sound increased the bandwidths. Here, we compared visual vs. sound adaptation effects, specifically analysing the raw tuning curves by computing the area under the curve (AUC) on a trial-by-trial basis. We report that sound adaptation elicited broader tuning curves accompanied with increased variance in the supra- and infra-granular layers, compared with visual adaptation. These findings suggest unique modulation of dendritic structure by distinct adaptation protocols, resulting in disparate tunings. We suggest that broader tuning curves after sound adaptation may keep the visual cortex prepared across a spectrum of abstract representations that match with visual stimuli.

neuroscience↗

bioRxiv2023

Temporally organized representations of reward and risk in the human brain

AO_SCPLOWBSTRACTC_SCPLOWThe value and uncertainty associated with choice alternatives constitute critical features along which decisions are made. While the neural substrates supporting reward and risk processing have been investigated, the temporal organization by which these computations are encoded remains elusive. Here we leverage the high spatiotemporal precision of intracranial electroencephalography (iEEG) to uncover how representations of decision-related computations unfold in time. We present evidence of locally distributed representations of reward and risk variables that are temporally organized across multiple regions of interest. Reward outcome representations across wide-spread regions follow a temporally cascading order along the anteroposterior axis of the brain. In contrast, expected value can be decoded from multiple regions at the same time, and error signals in both reward and risk domains reflect a mixture of sequential and parallel encoding. We highlight the role of the anterior insula in generalizing between reward prediction error (RePE) and risk prediction error (RiPE), within which the encoding of RePE in the distributed iEEG signal predicts RiPE. Together our results emphasize the utility of uncovering temporal dynamics in the human brain for understanding how computational processes critical for value-based decisions under uncertainty unfold.

neuroscience↗