ORCID

0000-0002-5950-1577

Keywords

Uncertainty, Ambiguity, Neuroimaging (fNIRS), Fake News, Prefrontal Cortex

Abstract

A pertinent next step in investigating fake news, is exploring the inherent ambiguity of news headlines through the lens of uncertain decision-making theories. Few studies have done so while investigating the established neural correlates associated with uncertainty in the prefrontal cortex (PFC). A set of three studies was conducted examining the underlying neural mechanisms associated with ambiguity of news headlines, individuals’ polarization, and their decision behavior. Study 1 validated news headlines in terms of ambiguity (1-7 scale). Experiment 1 investigated choice behavior in an uncertain decision task with ambiguous news headlines, while recording activation in the prefrontal cortex using fNIRS. It was expected that participants would avoid gambling on more ambiguous headlines (Hypothesis 1) and neural activation would increase accordingly in the ventrolateral (vlPFC) and medial PFC (mPFC) (Hypothesis 2), but this was not supported. Instead, risk aversion and cognitive reflection were associated with increases in the dlPFC and frontopolar regions. Experiment 2 investigated accuracy with a yes/no task. It was expected that participants’ accuracy would be lower when responding to more ambiguous headlines (Hypothesis 1) and that neural activation would increase (vlPFC and mPFC) (Hypothesis 2), but this was not supported. Instead, ambiguity aversion was related to increases in the mPFC. Polarization was anticipated to moderate the relationships between ambiguity and choice, and accuracy, but this was not true for either experiment (Hypothesis 3). Stimulus factors (politicality and veracity), and individual differences (ambiguity aversion, cognitive reflection, and risk aversion), were found to be better predictors of both behavior and neural activation than ambiguity alone. This research found that ambiguity is not the sole predictor of behavior when interacting with news stimuli of varying ambiguity, as other uncertain decision tasks found. Instead, aversion, politicality, and ambiguity’s relationship with veracity must be considered to disentangle behavior and the underlying neural correlates.

Completion Date

2025

Semester

Fall

Committee Chair

Lighthall, Nichole

Degree

Doctor of Philosophy (Ph.D.)

College

College of Sciences

Department

Psychology

Format

PDF

Identifier

DP0029773

Document Type

Thesis

Campus Location

Orlando (Main) Campus

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