Life Sciences Commons^™

Affective Liking Influences Reward Processing In Depression: A Computational Eeg Approach, Garima Singh

Psychology ETDs

Reinforcement learning (RL) enables agents to learn through interaction with their environment. This empowers individuals to optimize actions in complex and dynamic settings. The component of event related potential (ERP) termed as the Reward Positivity (RewP) evidently signifies a fundamental reward prediction error (RPE) associated with rewards. This characteristic implies that it represents a fundamental computational process in the assessment of RL. When a reward is particularly pleasurable or liked by an individual, it tends to elicit an amplified RewP signal, reflecting the heightened positive affect. RPE arises from disparities between anticipated and actual rewarding outcomes and is known to …

Eeg Features Of Explore-Exploit Decision-Making In Alcohol Use Disorder, Ethan Campbell

Psychology ETDs

Little research has assessed explore-exploit behavior in addiction using drug cues and even fewer studies have measured the neural activity underlying these behaviors. The present study aims to explore brain mechanisms of disordered decision-making in alcohol use disorder (AUD) through electroencephalography (EEG) during performance of a novelty bandit task with alcohol imagery and using a validated computational model of explore-exploit dynamics. Individuals with AUD (n = 28) and age and sex-matched controls (n = 27) showed differences in choice behavior and showed differences in EEG activity as a function of exploratory behavior, chosen stimulus type, and explore-exploit computational …

Hippocampal Functional Activity Following Prenatal Alcohol Exposure, Ryan E. Harvey

Psychology ETDs

Prenatal alcohol exposure (PAE) is among the most common developmental insults to the nervous system and is characterized by spatial memory disruption. There is a pressing need to identify physiological alterations that help explain this memory impairment. The hippocampal (HPC) formation and connected regions are a compelling candidate for this purpose as they are vital for navigation, spatial memory, and memory consolidation. This document is broken up into 3 main parts, a detailed review of the prior literature followed by several experiments. First, It starts out with a comprehensive review on spatial behavioral impairments following PAE and the synaptic & …

Electrophysiological Mechanisms For Preparing Control In Time, Jacqueline Rosemary Janowich

Psychology ETDs

Cognitive control is critical in guiding goal-directed behavior, preparing neural resources and adapting processing to promote optimal action in a given environment. According to the Dual Mechanisms of Control theory (Braver, 2012), control can be dichotomized into proactive and reactive modes of control, utilized reciprocally in ahead-of-time preparation versus last-minute, stimulus-evoked reaction. Although a substantial body of work has tested differences between proactive control and reactive control, the underlying assumption of proactive control as a unitary process has not been systematically investigated. Very little is known as to how or when proactive control is initiated, sustained, or implemented.

As time …

Neurocognitive Markers Of Cognitive Control In Schizophrenia And Functional Outcomes, Sephira Ryman

Psychology ETDs

Impaired cognitive function results in decreased objective quality of life and community functioning in schizophrenia, resulting in the largest indirect costs from the disease. Disrupted proactive cognitive control, a form of early selection and active goal maintenance, is hypothesized to underlie the broad cognitive deficits observed in patients with schizophrenia. The current study utilized novel electrophysiological (EEG) analytic approach to examine proactive and reactive cognitive control deficits in schizophrenia patients. Behavioral results highlight that patients exhibited a general reduction in reaction time across two multisensory cognitive control tasks, with selective deficits on proactive conditions relative to reactive conditions. The relative …

Moderate Prenatal Alcohol Exposure Impairs Performance In An Object-Place-Paired-Associate Task, Lilliana May Sanchez

Psychology ETDs

Memory impairments, including spatial and object processing, are often observed in individuals with Fetal Alcohol Spectrum Disorder. Much attention has been directed towards the hippocampus, which displays significant alterations after moderate prenatal alcohol exposure (PAE). In the present study, we tested a moderate PAE rat model in an object-place-paired-associate (OPPA) task, previously shown to require hippocampal processing. The OPPA task was composed of training rats to discriminate between an identical pair of objects presented in 180° opposite arms of a radial arm maze. Animals were given a total of 10 trials per day over 14 consecutive days of training and …

Functional Neural Connectivity Associated With Moral Processing In Healthy And Antisocial Samples, Samantha Jean Fede

Psychology ETDs

Although research finds that brain abnormalities during moral decisions underlie traits that lead to crime, understanding of these neural dynamics is limited. Here we use two samples to explore the role network engagement and components during moral processing. We used independent component analysis and functional network connectivity analysis to examine hemodynamic response during an fMRI task of moral processing. Eighty-four community and 539 incarcerated adult men and women participated; MANCOVA and machine learning algorithms were used to identify individual and group differences in both samples. We found patterns of neural engagement and connectivity consistent with proposed models of moral cognition …

Relationship Between Structure And Functional Connectivity Within The Default Mode Network, Andrei A. Vakhtin

Psychology ETDs

We proposed a novel measure of conceptualizing dynamic functional network connectivity (FNC) in the human brain using flexibility of functional connectivity (fFC), which captures the variance of functional connectivity across time. In task-free fMRI scans (N = 122), this measure was demonstrated to correspond to the underlying structural connectivity (SC) within the default mode network (DMN), while static functional connectivity (sFC) did so to a relatively low degree. As SC likely does not develop to facilitate task-free brain function, but rather to integrate information during cognitive engagement, we argue that fFC can estimate the potential functional connectivity exhibited outside of …