Adaptive decision-making is not only about choosing the correct option. It also requires choosing at the right speed. In uncertain environments, the brain must continuously manage the trade-off between accuracy and reaction time: waiting longer can improve decisions, but waiting too long may reduce reward rate. How cortico-basal ganglia-thalamic (CBGT) circuits learn to tune thisLire la suite « How basal ganglia subnetworks tune decision policies to increase reward rate »
Archives de l’étiquette : jyotika
L-Dopa reshapes aperiodic brain bursts in Parkinson’s disease
Parkinson’s disease is classically associated with abnormal rhythmic activity in cortico-basal ganglia circuits, especially excessive beta-band synchronization. Yet brain activity is not made only of regular oscillations. It also contains brief, irregular, aperiodic bursts that propagate across regions and may reflect the brain’s capacity to flexibly coordinate distributed activity. In this study, in collaboration withLire la suite « L-Dopa reshapes aperiodic brain bursts in Parkinson’s disease »
What if all these different oscillations where entangled in a network of interdependence?
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? »
CBGTPy: a flexible virtual laboratory for biological decision-making
Decision-making depends on the coordinated activity of cortico-basal ganglia-thalamic circuits. These circuits help the brain evaluate alternatives, select actions, suppress inappropriate responses, and learn from reward. Yet they are difficult to study because behavior emerges from interactions between many pathways, timescales, and cell populations. CBGTPy was developed to make these interactions easier to model, manipulate,Lire la suite « CBGTPy: a flexible virtual laboratory for biological decision-making »
Mapping the energy landscape of cognition in adolescent-onset schizophrenia
Cognitive difficulties are among the most disabling aspects of schizophrenia, and they are often particularly severe in adolescent-onset schizophrenia. Yet standard neuroimaging analyses usually focus either on regional activation — which areas are more or less active — or on functional connectivity — which areas fluctuate together. In this study, in collaboration with Konasale PrasadLire la suite « Mapping the energy landscape of cognition in adolescent-onset schizophrenia »
Arkypallidal neurons in the external globus pallidus can mediate inhibitory control by altering competition in the striatum
Stopping an action at the right moment is a fundamental form of cognitive control. Whether avoiding an obstacle, cancelling a planned movement, or adapting to a sudden change in the environment, the brain must sometimes rapidly suppress an action that is already being prepared. This process, known as reactive inhibitory control, has classically been attributedLire la suite « Arkypallidal neurons in the external globus pallidus can mediate inhibitory control by altering competition in the striatum »
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 »
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 »