Modeling Trait Anxiety: From Computational Processes to Personality

Abstract

Computational methods are increasingly being applied to the study of psychiatric disorders. Often, this involves fitting models to the behavior of individuals with subclinical character traits that are known vulnerability factors for the development of psychiatric conditions. Anxiety disorders can be examined with reference to the behavior of individuals high in “trait” anxiety, which is a known vulnerability factor for the development of anxiety and mood disorders. However, it is not clear how this self-report measure relates to neural and behavioral processes captured by computational models. This paper reviews emerging computational approaches to the study of trait anxiety, specifying how interacting processes susceptible to analysis using computational models could drive a tendency to experience frequent anxious states and promote vulnerability to the development of clinical disorders. Existing computational studies are described in the light of this perspective and appropriate targets for future studies are discussed.

A machine learning approach to identifying objective biomarkers of anxiety and stress

“…For each epoch, Welch's power spectral density estimate was used to transform data from the time domain to the frequency domain in order to decompose the signal and calculate absolute and relative band powers, asymmetries, and coherence in addition to the phase of the EEG channel signals. Band powers calculated included delta (1-4 Hz), theta (4-8 Hz), alpha (8)(9)(10)(11)(12)(13) Hz), low beta (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25), high beta (25)(26)(27)(28)(29)(30), and gamma (30-50 Hz) from the prefrontal, frontal, temporal, parietal, and occipital brain regions.…”

“…Unmanaged or chronic stress has been implicated in the process of conversion to anxiety disorders. Understanding the relationship between early-life stressful events or chronic, unmanaged stress may help uncover the mechanisms underlying the onset of anxiety disorders (65).…”

“…Anxiety disorders are defined by excessive or uncontrolled anticipation of uncertain threat that can lead people to seek medical attention (8). Various social and biological factors (9) may render some individuals more vulnerable to developing anxiety disorders (10). Trait anxiety is operationalized as the proneness to experience maladaptive anxious states and foreshadows vulnerability to developing a true anxiety disorder (11).…”

“…Stress can be a major anxiogenic process. Stressful events induce physiological responses, or allostasis, (12) that generate a transient increase in state anxiety (11), and early life stressful events or chronic, unmanaged stress may predispose individuals to developing anxiety disorders (9).…”

Recent advances in computational epigenetics

“…Computational models are also being developed for behavior and neural activity associated with anxiety traits and mental illness, and a recent review discusses the interplay of environmental factors with epigenetic regulation and plasticity in order to explore development of psychiatric disorders. 144 New model paradigms are still being explored to describe fundamental epigenetic mechanisms and processes involved in phenotypic plasticity. One such proposed 145 advocates the use of insect-based models to represent environmental or lifestyle insults affecting epigenetic regulation, since insects have the ability to produce distinct phenotypic variants from the same genotype through transcriptional reprogramming.…”