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INTRODUCTION
The Barccsyn Seminar Cycle, funded by the SGR “Network Dynamics”, aims to invite researchers from abroad in computational and systems neuroscience to Barcelona. We are excited to hear about their own work, as well as to have them get to know the growing Barccsyn community. In this vein we encourage our invited speakers to spend enough time in Barcelona to visit several labs, ideally one day and a half.
next session
Date: Monday, February 17th, 2025
Time: TBP
Place: TBP
Probing economic decision preferences in mice
Abstract:
Real life decisions often occur in volatile environments and require strategic interaction between multiple decision makers. Imagine decisions at a poker table or foraging decisions in a competitive, changing environment. In both situations, animals make decisions based on incomplete information, under risk and uncertainty, and in a multi-agent social context. Due to the multiplexed and dynamic nature of these types of decisions, there are usually no uniquely correct answers. Instead, choices reflect individuals’ varied decision preferences that lead to differential short-term and long-term gains. Our goal is to understand how animals make flexible decisions under risk and social influence, and the neural circuit mechanisms underlying these choices. Towards this goal, we combine theory-motivated behavioural designs in mice, quantitative extraction of animals’ internal states, large-scale, cellular-resolution monitoring and manipulation of brain activity during decision tasks, and computational modelling. In this talk, I will present our progress in probing the behavioural and neural mechanisms for value-based decision-making under risk and in a multi-agent context.
Chunyu Ann Duan
Sainsbury Wellcome Centre - University College London
Ann Duan joined the faculty at the Sainsbury Wellcome Centre in summer 2021. She obtained her PhD in Neuroscience at Princeton University, where she studied prefrontal and collicular contributions to executive functions with Carlos Brody. In 2016, Ann became a Simons Collaboration on the Global Brain postdoctoral fellow in Ning-long Xu’s lab at the Institute of Neuroscience in Shanghai, where she used circuit-level tools to investigate cortico-subcortical cooperation during decision formation and maintenance.
organizers
Alex Hyafil | Centre de Recerca Matemàtica
Alex Roxin | Centre de Recerca Matemàtica
Klaus Wimmer | Centre de Recerca Matemàtica
PAST SESSIONS
Date:Thursday, June 13th, 2024
Speaker: Alaa Ahmed (University of Colorado Boulde)
Title: Movement vigor as a reflection of internal decision variables during deliberation and learning
Abstract: To understand subjective evaluation of an option, various disciplines have quantified the interaction between reward and effort during decision making, producing an estimate of economic utility, namely the subject ‘goodness’ of an option. However, those same variables that affect the utility of an option also influence the vigor (speed) of movements towards that option. To better understand this, we have developed a mathematical framework demonstrating how utility can influence not only the choice of what to do, but also the speed of the movement follows. I will present results demonstrating that expectation of reward increases speed of saccadic eye and reaching movements, whereas expectation of effort expenditure decreases this speed. Intriguingly, when deliberating between two visual options, saccade vigor to each option increases differentially, encoding their relative value. Even when option value is hidden and must be learned, vigor can reveal the trial-to-trial prediction error and the consequent update of learned value. These results and others imply that vigor may serve as a new, real-time metric with which to quantify and track the evolution of subjective value, and that the neural circuits responsible for the control of movement are inextricably linked to the circuits involved in decision making.
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Date: Thursday, May 23rd, 2024
Speaker: Ralf Haefner (Rochester University)
Title: Behavioral and neural signatures of approximate inference during passive and active vision
Abstract: Perception requires the combination of uncertain sensory inputs with prior expectations. How such probabilistic computations might be implemented in the brain is a key question in systems neuroscience. Most of my talk will present recent work on temporal biases in evidence accumulation tasks. We found that approximate hierarchical inference results in a confirmation bias whose strength depends on the task in a predictable way. We verified our predictions using psychophysical experiments and showed that the proposed underlying mechanism – a positive feedback loop between decision-making and sensory areas – can reconcile a wide range of prior studies who differed in the biases they found. Next, we extended our work to the case of active sensing and showed that human eye-movements suffer from a similar confirmation bias as they collect information across the visual scene, again explainable by an approximate Bayesian observer. Interestingly, a neural signature of such computations include an increase in differential correlations with task learning in contradiction to classic feedforward models of noise correlations, a prediction we confirmed in monkey neurophysiology experiments.
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For inquiries about this event please contact the Scientific Events Coordinator Ms. Núria Hernández at nhernandez@crm.cat
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