Clarifying the mechanisms of cognitive dysfunction in ADHD and tobacco withdrawal with a model-based cognitive neuroscience approach

Restricted (Penn State Only)
Author:
Weigard, Alexander Samuel
Graduate Program:
Psychology
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
July 07, 2017
Committee Members:
  • Cynthia Huang-Pollock, Dissertation Advisor
  • Cynthia Huang-Pollock, Committee Chair
  • Koraly Elisa Perez-Edgar, Committee Member
  • Stephen Wilson, Committee Member
  • Peter Molenaar, Outside Member
Keywords:
  • model-based cognitive neuroscience
  • Bayesian modeling
  • ADHD
  • tobacco withdrawal
Abstract:
Aberrations in controlled cognitive processes, such as working memory, response inhibition and decision making, are ubiquitous in psychiatric populations and form the basis of many leading etiological theories of psychological dysfunction. However, the study of cognitive deficits in psychopathology is currently limited by two separate, but interrelated factors: 1) theories of “cognitive control” and related constructs that are fundamentally descriptive, rather than explanatory accounts of the mechanisms that underlie these functions and 2) a dearth of methods for clarifying the specific functional mechanisms that lead to observed cognitive performance deficits in clinical populations. An approach based in model-based cognitive neuroscience, an emerging field in which formal models that describe the functional mechanisms that allow humans to complete cognitive tasks are integrated with neuroscience methods and theory, may be able to overcome these challenges by making the mechanistic differences between clinically-relevant conditions explicit. This work contains manuscripts from three separate empirical studies which used a model-based cognitive neuroscience approach to better understand the basic mechanisms that lead to cognitive dysfunction in two clinical conditions: 1) childhood Attention-Deficit / Hyperactivity Disorder (ADHD) and 2) withdrawal from tobacco in regular smokers. Broadly, results from these studies suggest that cognitive differences in individuals with ADHD can be attributed to a reduced neural signal-to-noise ratio, but that cognitive impairment following tobacco withdrawal can be attributed to intermittent attentional lapses, potentially related to the experience of subjective discomfort during withdrawal. Taken together, these findings indicate that a model-based cognitive neuroscience approach may be instrumental for elucidating the causes of cognitive dysfunction in a variety of clinical conditions.