Hierarchical reasoning in the brain

When we interact in an uncertain environment, we continuously reason to disambiguate internal and external sources of uncertainty at multiple spatiotemporal scales to guide our goal-directed behavior. Understanding the neural mechanism of this reasoning behavior is essential for consequential applic...

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Bibliographic Details
Main Author: Sarafyazd, Morteza
Other Authors: Jazayeri, Mehrdad
Format: Thesis
Published: Massachusetts Institute of Technology 2022
Online Access:https://hdl.handle.net/1721.1/140134
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author Sarafyazd, Morteza
author2 Jazayeri, Mehrdad
author_facet Jazayeri, Mehrdad
Sarafyazd, Morteza
author_sort Sarafyazd, Morteza
collection MIT
description When we interact in an uncertain environment, we continuously reason to disambiguate internal and external sources of uncertainty at multiple spatiotemporal scales to guide our goal-directed behavior. Understanding the neural mechanism of this reasoning behavior is essential for consequential applications in brain sciences. In this thesis, I address hierarchical reasoning at three levels of behavior, neural circuit, and computational models. First, I developed behavioral experiments to examine the reasoning behavior in dynamic environments with two hierarchical sources of uncertainty. The rational behavior necessitates evidence integration under multiple sources of uncertainty to update internal belief about the external environment. This behavioral study showed that human and non-human primates are able to reason accordingly by accumulating evidence to update their belief in a longer timescale. Second, I performed electrophysiology in the frontal cortex. The concurrent neural recordings revealed that brain regions in the frontal cortex carry signals related to reasoning behavior and performance monitoring. Third, to interpret the neural results, a probabilistic integrator model is implemented to address the key interpretable variables of the behavior. Finally, after observing the neural data, I aimed to explore neural hypotheses of the behavior through in-silico simulations of two neural-network models to perform the reasoning task. These simulations led to a better evaluation of proposed neural hypotheses relevant to key behavioral variables.
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spelling mit-1721.1/1401342022-02-08T03:01:48Z Hierarchical reasoning in the brain Sarafyazd, Morteza Jazayeri, Mehrdad Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences When we interact in an uncertain environment, we continuously reason to disambiguate internal and external sources of uncertainty at multiple spatiotemporal scales to guide our goal-directed behavior. Understanding the neural mechanism of this reasoning behavior is essential for consequential applications in brain sciences. In this thesis, I address hierarchical reasoning at three levels of behavior, neural circuit, and computational models. First, I developed behavioral experiments to examine the reasoning behavior in dynamic environments with two hierarchical sources of uncertainty. The rational behavior necessitates evidence integration under multiple sources of uncertainty to update internal belief about the external environment. This behavioral study showed that human and non-human primates are able to reason accordingly by accumulating evidence to update their belief in a longer timescale. Second, I performed electrophysiology in the frontal cortex. The concurrent neural recordings revealed that brain regions in the frontal cortex carry signals related to reasoning behavior and performance monitoring. Third, to interpret the neural results, a probabilistic integrator model is implemented to address the key interpretable variables of the behavior. Finally, after observing the neural data, I aimed to explore neural hypotheses of the behavior through in-silico simulations of two neural-network models to perform the reasoning task. These simulations led to a better evaluation of proposed neural hypotheses relevant to key behavioral variables. Ph.D. 2022-02-07T15:26:00Z 2022-02-07T15:26:00Z 2021-09 2021-11-12T14:45:00.372Z Thesis https://hdl.handle.net/1721.1/140134 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Sarafyazd, Morteza
Hierarchical reasoning in the brain
title Hierarchical reasoning in the brain
title_full Hierarchical reasoning in the brain
title_fullStr Hierarchical reasoning in the brain
title_full_unstemmed Hierarchical reasoning in the brain
title_short Hierarchical reasoning in the brain
title_sort hierarchical reasoning in the brain
url https://hdl.handle.net/1721.1/140134
work_keys_str_mv AT sarafyazdmorteza hierarchicalreasoninginthebrain