Basic Science and Pathogenesis.

Area of Science:

• Cognitive Neuroscience
• Computational Psychiatry

Background:

• Mental effort is key to cognitive control, with exogenous (automatic) and endogenous (intentional) dimensions.
• Cognitive control involves managing automatic processes, like reading words, to achieve goals, as seen in the Stroop task.

Purpose of the Study:

• To investigate the role of voluntary mental effort in cognitive control.
• To model the Stroop task using active inference to understand effort modulation.

Main Methods:

• Twenty healthy volunteers performed the Stroop task under maximal exertion (EXR) and relaxed (RLX) conditions.
• A two-layer generative model within the active inference framework was used to estimate bias (e) and motivation (c) parameters.

Main Results:

• The maximal exertion condition significantly increased the motivation parameter (c).
• The bias parameter (e), representing word-reading tendency, was not significantly affected by exertion.
• Behavioral changes were attributed to increased endogenous effort, enhancing motivation.

Conclusions:

• Voluntary mental effort enhances endogenous motivation rather than altering ingrained response biases.
• Deficits in effort regulation are relevant to neurodegenerative diseases like Alzheimer's and Parkinson's.
• The computational approach provides a framework for assessing cognitive and motivational states in clinical settings.