Bolsa de TT-V em Tecnologia da Informação/Computação

Área de conhecimento: Ciência da Computação

Pesquisa FAPESP magazine presents: "The Statistician Brain"

NeuroMat's study on "Retrieving the structure of probabilistic sequences of auditory stimuli from EEG data" was featured on the last issue of science communication magazine Pesquisa FAPESP. The piece is called "The Statistician Brain" as NeuroMat's paper relates to a classical idea by Hermann von Helmholtz that the brain acts like a statistician as it models stimuli from the environment.

Predicting Upcoming Events Occurring in the Space Surrounding the Hand

Predicting upcoming sensorimotor events means creating forward estimates of the body and the surrounding world. This ability is a fundamental aspect of skilled motor behavior and requires an accurate and constantly updated representation of the body and the environment. To test whether these prediction mechanisms could be affected by a peripheral injury, we employed an action observation and electroencephalogram (EEG) paradigm to assess the occurrence of prediction markers in anticipation of observed sensorimotor events in healthy and brachial plexus injury (BPI) participants. Nine healthy subjects and six BPI patients watched a series of video clips showing an actor’s hand and a colored ball in an egocentric perspective. The color of the ball indicated whether the hand would grasp it (hand movement), or the ball would roll toward the hand and touch it (ball movement), or no event would occur (no movement). In healthy participants, we expected to find distinct electroencephalographic activation patterns (EEG signatures) specific to the prediction of the occurrence of each of these situations. Cluster analysis from EEG signals recorded from electrodes placed over the sensorimotor cortex of control participants showed that predicting either an upcoming hand movement or the occurrence of a tactile event yielded specific neural signatures. In BPI participants, the EEG signals from the sensorimotor cortex contralateral to the dominant hand in the hand movement condition were different compared to the other conditions. Furthermore, there were no differences between ball movement and no movement conditions in the sensorimotor cortex contralateral to the dominant hand, suggesting that BPI blurred specifically the ability to predict upcoming tactile events for the dominant hand. These results highlight the role of the sensorimotor cortex in creating estimates of both actions and tactile interactions in the space around the body and suggest plastic effects on prediction coding following peripheral sensorimotor loss.

Bolsa de TT-IV em Tecnologia da Informação

Área de conhecimento: Ciência da Computação

The effect of graph connectivity on metastability in a stochastic system of spiking neurons

Morgan André and Léo Planche

We consider a continuous-time stochastic model of spiking neurons. In this model, we have a finite or countable number of neurons which are vertices in some graph G where the edges indicate the synaptic connection between them. We focus on metastability, understood as the property for the time of extinction of the network to be asymptotically memory-less, and we prove that this model exhibits two different behaviors depending on the nature of the specific underlying graph of interaction G that is chosen.

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Podcast A Matemática do Cérebro
Podcast A Matemática do Cérebro
NeuroMat Brachial Plexus Injury Initiative
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Neuroscience Experiments System
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NeuroMat Parkinson Network
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NeuroMat's scientific-dissemination blog
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