How the brain decides when to work and when to rest: dissociation of implicit-reactive from explicit-predictive...

Area of Science:

• Cognitive Science
• Neuroscience
• Behavioral Economics

Background:

• The allocation of effort over time presents a fundamental cost-benefit challenge.
• Economic models predict predetermined effort durations, while exercise science highlights on-the-fly adjustments based on physiology.

Purpose of the Study:

• To propose and validate a general model integrating economic and physiological perspectives on effort allocation.
• To investigate the interplay between implicit, reactive adjustments and explicit, predictive computations in effort management.

Main Methods:

• A novel computational model of effort allocation was developed, incorporating a 'cost evidence' variable.
• Behavioral experiments with 121 healthy humans manipulated effort duration and difficulty to test the model.
• Dissociated implicit-reactive from explicit-predictive computations through task design.

Main Results:

• Effort and rest durations dynamically adapted to real-time 'cost evidence' levels.
• Observed 'cost evidence' fluctuations did not align with subjective ratings of exhaustion.
• Actual task difficulty influenced effort duration, while expected difficulty affected rest duration.

Conclusions:

• 'Cost evidence' is implicitly monitored online, accumulating proportionally to actual task difficulty.
• Effort allocation decisions involve both real-time physiological feedback and anticipatory adjustments based on expected difficulty.