Overview
- Researchers at TUM and FAU report in Nature Neuroscience that BOLD signal changes can oppose underlying neuronal oxygen consumption in a substantial fraction of measurements.
- The team simultaneously tracked oxygen consumption with a quantitative MRI method while participants performed standard cognitive tasks such as mental arithmetic and memory recall.
- In multiple regions, increased BOLD coincided with reduced metabolic demand, while decreased BOLD appeared alongside heightened oxygen use, indicating dissociations from assumed neurovascular coupling.
- Analyses suggest some areas meet extra energy needs by extracting more oxygen from an unchanged blood supply rather than increasing perfusion, creating misleading blood-flow–based readouts.
- Authors say interpretations of prior fMRI studies, including work on depression, Alzheimer’s and aging, require reassessment, and they recommend pairing conventional scans with quantitative metabolic measures.