Restoration requires genuine fatigue: Strengthening green-space cognition research

Despite robust evidence for its affective benefits, the cognitive record for natureexposure remains inconclusive, marked by small effects and substantial heterogeneity.This letter argues that these inconsistencies stem from methodological challenges,principally the failure to standardise methods for inducing the cognitive fatigue that is aprerequisite for restoration. I posit that a reliance on high-level psychological modelshas led to the use of brief, low-load induction protocols, which are insufficient forproducing a genuine neuro-metabolic state of fatigue. To address this, I propose astandardised 'Induce–Expose–Recover' framework that imports the rigour of cognitivefatigue science, advocating for sustained, high-load tasks and multi-modalassessment. Adopting this neurobiologically-grounded approach will enable the field toconduct decisive tests of restoration, moving beyond ambiguous findings of cognitiveenhancement.