Linking neural activity to sensory, motor or cognitive processes is an ongoing goal in Neuroscience and articular attention has been devoted to the role of brain oscillations, analyzed by averaging over many trials in suitably designed tasks. Previous findings offer a glimpse of the complexity of the overall picture, but have also limitations. First, searchingLire la suite « What if all these different oscillations where entangled in a network of interdependence? »
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Subject-specific maximum entropy model of resting state fMRI shows diagnostically distinct patterns of energy state distributions
Existing neuroimaging studies of psychotic and mood disorders have reported regional brain activation differences (first-order properties) and alterations in functional connectivity based on pairwise correlations in activation (second-order properties). In this preprint, in collaboration with Jonathan Rubin, Konasal Prasad et al. (Pittsburgh, PA), we use a generalized Ising model, also called a pairwise maximum entropyLire la suite « Subject-specific maximum entropy model of resting state fMRI shows diagnostically distinct patterns of energy state distributions »
Different Faces of Medial Beta-Band Activity Reflect Distinct Visuomotor Feedback Signals
Beta-band activity reflects neural processes well beyond sensorimotor functions, including cognition and motivation. In this Journal of Neuroscience article in collaboration with Nicola Malfait (Marseille), by disentangling alternative spatio-temporal-spectral patterns of possible beta-oscillatory activity, we reconcile a seemingly discrepant literature. First, high-beta power in the medial frontal cortex showed opposite modulations separated in time inLire la suite « Different Faces of Medial Beta-Band Activity Reflect Distinct Visuomotor Feedback Signals »
Competing neural representations of choice shape evidence accumulation in humans
Making adaptive choices in dynamic environments requires flexible decision policies. Previously, we showed how shifts in outcome contingency change the evidence accumulation process that determines decision policies. In this eLife article we published in collaboration with Jonathan Rubin, Timothy Verstynen (Pittsburgh, PA) et al, we used in silico experiments to generate predictions and show howLire la suite « Competing neural representations of choice shape evidence accumulation in humans »
CBGTPy: An extensible cortico-basal ganglia-thalamic framework for modeling biological decision making
In this preprint, in collaboration with Jonathan Rubin, Timothy Verstynen (Pittsburgh, PA) and Catalina Vich (Palma, Spain) we introduce CBGTPy, a virtual environment for designing and testing goal-directed agents with internal dynamics that are modeled on the cortico-basal-ganglia-thalamic (CBGT) pathways in the mammalian brain. CBGTPy enables researchers to investigate the internal dynamics of the CBGTLire la suite « CBGTPy: An extensible cortico-basal ganglia-thalamic framework for modeling biological decision making »
Graph-based features to capture the embodiment of adaptive behavior
The cerebellar cortex encodes sensorimotor adaptation during skilled locomotor behaviors, however the precise relationship between synaptic connectivity and behavior is unclear. In our recent Nature Communications paper (in collaboration with Philippe Isope’s group at INCI, Strasbourg), we studied synaptic connectivity between granule cells (GCs) and Purkinje cells (PCs) in murine acute cerebellar slices using photostimulationLire la suite « Graph-based features to capture the embodiment of adaptive behavior »
Uncoupling the roles of firing rate and spike bursts in shaping the gpe-stn beta band oscillations.
The excess of 15-30 Hz (β-band) oscillations in the basal ganglia is one of the key signatures of Parkinson’s disease (PD). The STN-GPe network is integral to generation and modulation of β band oscillations in basal ganglia. However, the role of changes in the firing rates and spike bursting of STN and GPe neurons in shaping theseLire la suite « Uncoupling the roles of firing rate and spike bursts in shaping the gpe-stn beta band oscillations. »
Homologous basal ganglia network models in physiological and parkinsonian conditions
The classical model of basal ganglia has been refined in recent years with discoveries of subpopulations within a nucleus and previously unknown projections. One such discovery is the presence of subpopulations of arkypallidal and prototypical neurons in external globus pallidus, which was previously considered to be a primarily homogeneous nucleus. Developing a computational model ofLire la suite « Homologous basal ganglia network models in physiological and parkinsonian conditions »