Mental Fatigue

Mental fatigue is a psychobiological state that develops after sustained periods of demanding cognitive activity, producing slower responses, reduced accuracy, and reduced motivation to keep investing effort. Boksem and Tops (2008) reviewed evidence that mental fatigue functions as a regulatory signal, similar to physical fatigue, that discourages further resource expenditure once a cost-benefit threshold is crossed, rather than reflecting a literal depletion of a fixed resource.

Reference: Boksem & Tops, 2008. The NeuroRank implementation holds the canonical form and scales interference via task-irrelevant stimulus density.

1. The visible drop in decision quality during the final best-of-five map of a long tournament day.
2. Late-night ranked sessions where mechanical execution stays intact but map reads and rotations get noticeably worse.
3. The distinction from tilt: mental fatigue accumulates with duration and time on task, while tilt is triggered by a specific costly outcome.

A single NeuroRank combine session is too short to directly reproduce extended mental fatigue, but the Consistency dimension and the Composure module's distraction phase both capture fatigue-adjacent degradation: rising RT variance and larger flanker-interference costs late in a module are the closest in-session proxy.