Lesion network localization of free will.
Level 4 - case-series / case-control
Case-series and case-control mapping study of patients with focal brain lesions
PubMed 30275309 · doi:10.1073/pnas.1814117115
What was done
Investigators applied lesion network mapping to patients with focal brain lesions causing disordered volition (akinetic mutism, n = 28) or disordered agency (alien limb syndrome, n = 50). They mapped heterogeneous lesion sites onto normative functional connectivity networks and evaluated network specificity against control brain lesions causing similar physical deficits without altered free will perception. Findings were also compared to brain stimulation sites and psychiatric neuroimaging literature.
What was found
Lesions causing akinetic mutism all localized to a single functional network defined by connectivity to the anterior cingulate cortex, whereas lesions causing alien limb syndrome localized to a distinct network defined by connectivity to the precuneus. Both network localizations were specific compared to control lesions. No quantitative statistical values or effect sizes were reported in the abstract.
Why it matters
This study provides an anatomical framework demonstrating that distinct components of free will perception—volition and agency—map to specific functional brain networks rather than isolated focal brain regions.
Limits
The abstract omits exact statistical test values, connectivity metrics, and sample sizes for the control lesion groups. The findings rely on retrospective case identification and infer network connectivity from normative connectome data rather than direct functional imaging of the affected individuals.