Search bioRxiv⌕ Search

Biology subjects

Pelosin, E.

Publications and source records attributed to Pelosin, E..

2 recordsLinked to original sources

Interactions between supervised and reinforcement learning processes in a neurorobotic model

Several influential works propose that the acquisition of motor behavior involves different learning mechanisms in the brain, in particular supervised and reinforcement learning, that are respectively associated with cerebellar-thalamocortical and basal ganglia-thalamocortical networks. Despite increasing evidence suggesting anatomical and functional interactions between these circuits, the learning processes operating within them are studied in isolation, neglecting their strong interdependence. This article proposes a bio-inspired neurorobotic model implementing a possible cooperation mechanism between supervised and reinforcement learning. The model, validated with empirical data from healthy participants and patients with cerebellar ataxia, shows how the integration of the two learning processes could lead to benefit both learning performance and movement accuracy.

bioengineering↗

Modulation of neural oscillations during working memory update, maintenance, and readout: an hdEEG study

Working memory (WM) performance is very often measured using the n-back task, in which the participant is presented with a sequence of stimuli, and required to indicate whether the current stimulus matches the one presented n steps earlier. In this study, we used high-density electroencephalography (hdEEG) coupled to source localization to obtain information on spatial distribution and temporal dynamics of neural oscillations associated with WM update, maintenance and readout. Specifically, we a priori selected regions from a large fronto-parietal network, including also the insula and the cerebellum, and we analyzed modulation of neural oscillations by event-related desynchronization and synchronization (ERD/ERS). During update and readout, we found larger {theta} ERS and smaller {beta} ERS respect to maintenance in all the selected areas. {gamma}LOW and {gamma}HIGH bands oscillations decreased in the frontal and insular cortices of the left hemisphere. In the maintenance phase we observed focally decreased {theta} oscillations and increased {beta} oscillations (ERS) in most of the selected posterior areas and focally increased oscillations in {gamma}LOW and {gamma}HIGH bands in the frontal and insular cortices of the left hemisphere. Finally, during WM readout, we also found a focal modulation of the {gamma}LOW band in the left fusiform cortex and cerebellum, depending on the response trial type (true positive vs. true negative). Overall, our study demonstrated specific spectral signatures associated with updating of memory information, WM maintenance and readout, with relatively high spatial resolution.

neuroscience↗