Sensorimotor Feedback Control Dysfunction as a Marker of Posttraumatic Stress Disorder.

Background: Posttraumatic stress disorder (PTSD) is characterized not only by its direct association with traumatic events but also by a potential deficit in inhibitory control across emotional, cognitive, and sensorimotor domains. Recent research has shown that a continuous sensorimotor feedback control task, the rapid assessment of motor processing paradigm, can yield reliable measures of individual sensorimotor control performance. This study used this paradigm to investigate control deficits in PTSD compared with both a healthy volunteer group and a non-PTSD psychiatric comparison group.

Out of control: computational dynamic control dysfunction in stress- and anxiety-related disorders.

Control theory, which has played a central role in technological progress over the last 150 years, has also yielded critical insights into biology and neuroscience. Recently, there has been a surging interest in integrating control theory with computational psychiatry. Here, we review the state of the field of using control theory approaches in computational psychiatry and show that recent research has mapped a neural control circuit consisting of frontal cortex, parietal cortex, and the cerebellum.

Polygenic risk for neuroticism is associated with less efficient control in more difficult situations.

Neuroticism is a heritable trait and a risk factor for mental health due to its relevance to poor control of negative events. To examine the relationship between genetic propensity for neuroticism and control processing, we used the polygenic risk score (PRS) approach and a stop signal task during fMRI. We hypothesized that genetic propensity for neuroticism may moderate control processing as a function of control difficulty.

Neural substrates of continuous and discrete inhibitory control.

Inhibitory control dysfunctions play an important role in psychiatric disorders but the precise nature of these dysfunctions is still not well understood. Advances in computational modeling of real-time motor control using a proportion-integral-derivative (PID) control framework have parsed continuous motor inhibition into a preemptive drive component (signified by the K parameter) and a reactive damping component (signified by the K parameter). This investigation examined the relationship between inhibitory control processing during a stop signal task and continuous motor control during a simulated one-dimensional driving task in a transdiagnostic sample of participants.

Rapid, reliable mobile assessment of affect-related motor processing.

Mobile technologies can be used for behavioral assessments to associate changes in behavior with environmental context and its influence on mental health and disease. Research on real-time motor control with a joystick, analyzed using a computational proportion-derivative (PD) modeling approach, has shown that model parameters can be estimated with high reliability and are related both to self-reported fear and to brain structures important for affective regulation, such as the anterior cingulate cortex. Here we introduce a mobile version of this paradigm, the rapid assessment of motor processing (RAMP) paradigm, and show that it provides robust, reliable, and accessible behavioral measurements relevant to mental health.

Mental Health Consequences of Traumatic Brain Injury.

Traumatic brain injury (TBI) is associated with a host of psychiatric and neurobehavioral problems. As mortality rates have declined for severe TBI, attention has turned to the cognitive, affective, and behavioral sequelae of injuries across the severity spectrum, which are often more disabling than residual physical effects. Moderate and severe TBI can cause personality changes including impulsivity, severe irritability, affective instability, and apathy.

Inhibitory failures in cocaine use disorder: Not paying attention when there is a need to be cautious.

Background: Stimulant use disorders, such as cocaine use disorder, are associated with significant impairment in inhibitory control, which has in turn been linked to difficulties maintaining abstinence following treatment. Here, we combine the Dynamic Belief Model (DBM) and a Hierarchical Drift Diffusion Model (HDDM) to examine whether individuals with cocaine use disorder have both strategic response updating and tactical speed accuracy trade-off problems during inhibitory control.

Methods: Twenty-seven individuals with cocaine use disorder and twenty-seven healthy control participants completed a Stop-Signal-Task (SST), in which one has to inhibit a motor response to a prepotent 2-alternative forced choice task on 25 % of the trials.

Symptoms of Posttraumatic Stress Disorder are Associated with Exaggerated Neural Response to Surprising Errors.

Posttraumatic stress disorder (PTSD) is characterized by exaggerated salience of previously innocuous cues and associated with hyperactivity of salience-related brain regions. Recently, computational models have been deployed to operationalize salience more precisely regarding surprise-driven learning, leading to findings that such learning is altered in anxiety-related disorders. In the present study, a sample of 20 combat veterans completed a probabilistic learning task during fMRI scanning.

A parallel accumulator model accounts for decision randomness when deciding on risky prospects with different expected value.

In decision-making situations individuals rarely have complete information available to select the best option and often show decisional randomness, i.e. given the same amount of knowledge individuals choose different options at different times.

Computational Evidence for Underweighting of Current Error and Overestimation of Future Error in Anxious Individuals.

Background: Real-time control of goal-directed actions requires continuous adjustments in response to both current error (i.e., distance from goal state) and predicted future error.

Attention Deficit Hyperactivity Disorder and Risk of Posttraumatic Stress and Related Disorders: A Prospective Longitudinal Evaluation in U.S. Army Soldiers.

Cross-sectional associations between attention deficit hyperactivity disorder (ADHD) and posttraumatic stress disorder (PTSD) have been observed, but longitudinal studies assessing this association are lacking. This prospective study evaluated the association between predeployment ADHD and postdeployment PTSD among U.S.

The effect of single-dose methylphenidate on the rate of error-driven learning in healthy males: a randomized controlled trial.

Rationale And Objectives: Norepinephrine mediates the adjustment of error-driven learning to match the rate of change of the environment, while phasic dopamine signals prediction errors. We tested the hypothesis that pharmacologic manipulation may modulate this process.

Methods: We administered a single dose of methylphenidate, a norepinephrine/dopamine reuptake inhibitor, or placebo in double-blind randomized fashion to 20 healthy human males, who then performed a probabilistic learning task.

Individual Differences in Subjective Utility and Risk Preferences: The Influence of Hedonic Capacity and Trait Anxiety.

Individual differences in decision-making are important in both normal populations and psychiatric conditions. Variability in decision-making could be mediated by different subjective utilities or by other processes. For example, while traditional economic accounts attribute risk aversion to a concave subjective utility curve, in practice other factors could affect risk behavior.

Prevention of Trauma and Stressor-Related Disorders: A Review.

Posttraumatic stress disorder (PTSD) is a common, frequently chronic, and disabling condition which, along with acute stress disorder (ASD), is categorized as a trauma- and stressor-related disorder by the DSM-5. These disorders are unique in requiring exposure to a severe stressor, which implies that potential sufferers could be identified and helped before developing a disorder. Research on prevention strategies for stress-related disorders has taken a number of avenues, including intervention before and after trauma and the use of both psychosocial and somatic approaches.

The neural basis of testable and non-testable beliefs.

Beliefs about the state of the world are an important influence on both normal behavior and psychopathology. However, understanding of the neural basis of belief processing remains incomplete, and several aspects of belief processing have only recently been explored. Specifically, different types of beliefs may involve fundamentally different inferential processes and thus recruit distinct brain regions.

Decision-Making Dysfunctions of Counterfactuals in Depression: Who Might I have Been?

Cognitive neuroscience enables us now to decompose major depressive disorder into dysfunctional component processes and relate these processes to specific neural substrates. This approach can be used to illuminate the biological basis of altered psychological processes in depression, including abnormal decision-making. One important decision-related process is counterfactual thinking, or the comparison of reality to hypothetical alternatives.