Electronic Theses and Dissertations

Date

2022

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Committee Chair

Nicholas Simon

Committee Member

Nicholas W Simon

Committee Member

Deranda B Lester

Committee Member

James G Murphy

Committee Member

Erin S Calipari

Abstract

In this dissertation, I recorded individual neuronal activity from the lateral orbitofrontal cortex of awake, freely moving animals as they behaved in a punishment-based risky decision-making task. In this risky decision-making task, subjects chose between a small food reward and a large food reward associated with either a 0% or 50% risk of a concurrent punishment in the form of a mild footshock. As the risk of punishment increased, subjects reduced choice of the large reward. To fully dissect the neuronal underpinnings throughout the decision-making process, I designed the behavioral paradigm to contain three distinct stages: deliberation, choice selection, and outcome anticipation. During each of these stages of decision-making, I identified distinct neuronal subpopulations encoding salient task information (such as reward magnitudes or current risk levels) and internal representations of information (such as potentially impending consequences resulting from recent risky behavior or a subjective willingness to engage in risk-taking). Close analysis of lateral orbitofrontal cortex activity during risky decision-making revealed 4 primary roles for lOFC in risky decision-making: 1) a safety signal encoding risk in the choice environment, 2) a warning signal predicting risky behavior and encoding potential consequences of recent risk-taking, 3) reward magnitude identity for distinct reward sizes, and 4) an integrated signal encoding salient information about currently available rewards.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest

Notes

Embargoed until 8/2/2023

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