E3 PreliminaryPreliminaryPEM not requiredCross-SectionalPeer-reviewedReviewed
Standard · 3 min
Functional brain connectivity of remembered fatigue or happiness in healthy adults: Use of arterial spin labeling.
Boissoneault, Jeff, Sevel, Landrew, Robinson, Michael E et al. · Journal of clinical and experimental neuropsychology · 2018 · DOI
Quick Summary
Researchers used brain scans to study what happens in the brain when healthy people remember feeling tired versus happy. They found that fatigue activated different brain regions than happiness did, particularly areas involved in vision and a structure called the globus pallidum. This helps scientists understand the brain basis of fatigue without the complications of studying people who have chronic fatigue syndrome with other medical conditions.
Why It Matters
This mechanistic study isolates the brain circuitry of fatigue in healthy controls without confounding comorbidities like depression or pain, providing a foundational understanding of fatigue neural mechanisms relevant to ME/CFS. By identifying specific brain networks associated with fatigue, it offers potential biomarkers and therapeutic targets for investigating fatigue pathophysiology in chronic conditions including ME/CFS.
Observed Findings
In-scanner fatigue recall produced mean VAS ratings of 31.85 (SD 20.61), while happiness induction produced VAS ratings of 46.07 (SD 18.99).
Fatigue was associated with altered functional connectivity in the globus pallidum, left lateral occipital cortex, and cuneus.
Happiness was associated with functional connectivity changes in the parahippocampal gyrus, supplemental motor areas, and right superior frontal gyrus.
Data-driven ICA identified intra-cerebellar networks showing significant associations with fatigue but not happiness ratings.
Permutation testing confirmed differential clustering patterns between fatigue and happiness conditions.
Inferred Conclusions
Functional interactions between the globus pallidum and occipital structures contribute to the generation of fatigue in healthy individuals.
Cortico-cerebellar interactions play an important role in producing subjective feelings of fatigue.
Occipital lobe functional connectivity contributes to both fatigue and happiness but with different network involvement patterns.
Remaining Questions
Do the brain connectivity patterns identified in healthy people undergoing experimental fatigue differ from those in people with ME/CFS or other chronic fatiguing illnesses?
What This Study Does Not Prove
This study does not demonstrate that ME/CFS fatigue arises from the same brain mechanisms as experimental fatigue in healthy people—ME/CFS involves post-exertional malaise, autonomic dysfunction, and persistent symptoms absent in this acute recall paradigm. The findings are correlational and do not establish causal relationships or explain why these brain regions become dysfunctional in disease states. Small sample size (n=17) and use of memory recall rather than actual fatigue-inducing exercise limits generalizability to real-world fatigue experiences.
Tags
Symptom:Fatigue
Biomarker:Neuroimaging
Method Flag:No ControlsSmall SampleExploratory Only
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Contribute
Private, reviewed by a human. Not a public comment thread.
How do these acute fatigue-related brain networks relate to post-exertional malaise or the persistent fatigue characteristic of ME/CFS?
Can interventions targeting globus pallidum-occipital or cortico-cerebellar connectivity alleviate fatigue in either healthy or chronically fatigued populations?
How do these findings relate to autonomic nervous system dysfunction observed in ME/CFS?