The transdiagnostic structure of mental effort avoidance.

The law of least mental effort states that, everything else being equal, the brain tries to minimize mental effort expenditure during task performance by avoiding decisions that require greater cognitive demands. Prior studies have shown associations between disruptions in effort expenditure and specific psychiatric illnesses (e.g.

Computational Phenotyping: Using Models to Understand Individual Differences in Personality, Development, and Mental Illness.

This paper reviews progress in the application of computational models to personality, developmental, and clinical neuroscience. We first describe the concept of a computational phenotype, a collection of parameters derived from computational models fit to behavioral and neural data. This approach represents individuals as points in a continuous parameter space, complementing traditional trait and symptom measures.

Incentives Boost Model-Based Control Across a Range of Severity on Several Psychiatric Constructs.

Background: Human decision making exhibits a mixture of model-based and model-free control. Recent evidence indicates that arbitration between these two modes of control ("metacontrol") is based on their relative costs and benefits. While model-based control may increase accuracy, it requires greater computational resources, so people invoke model-based control only when potential rewards exceed those of model-free control.

An intrinsic connectivity network approach to insula-derived dysfunctions among cocaine users.

Background: Addiction is a complex phenotype, though it consistently includes characteristics of impulsivity. A number of brain regions are suggested to be involved in cocaine addiction, including the insula, which serves diverse functions including interoceptive awareness and integration of neural signals from sensory, subcortical and frontal regions. Malfunction of this integration links impulsive behavior to the insula.

Excessive state switching underlies reversal learning deficits in cocaine users.

Background: Markers of chronic cocaine exposure on neural mechanisms in animals and humans is of great interest. The probabilistic reversal-learning task may be an effective way to examine dysfunction associated with cocaine addiction. However the exact nature of the performance deficits observed in cocaine users has yet to be disambiguated.