lesionbased

Lesion-based, sometimes written as lesion-based or lesionbased, refers to research and clinical practice that relies on focal brain or organ lesions to determine function, map cognitive processes, and guide interventions. In neuroscience and neuropsychology, lesion-based approaches examine how damage to specific regions relates to deficits, providing causal inferences about brain–behavior relationships. This contrasts with purely correlational imaging methods by leveraging natural experiments of injury or surgery.

Methods in lesion-based work typically involve identifying and delineating lesions on MRI or CT scans, normalizing findings to a common brain template, and applying lesion–symptom mapping analyses. Common techniques include voxel-based lesion–symptom mapping (VLSM) and region-of-interest lesion mapping, which relate the extent of damage in specific brain areas to performance on behavioral measures while controlling for factors such as lesion size and confounds. Lesion-based studies may also use longitudinal designs to track recovery and plasticity.

Applications span localization of cognitive functions (for example, language, memory, and executive control), investigation of neural networks disrupted by injury, and practical use in neurosurgical planning and prognosis. They also contribute to understanding the effects of brain tumors, stroke, epilepsy surgery, and traumatic brain injury on function, as well as guiding rehabilitation strategies.

Limitations include nonuniform lesion distribution across individuals, heterogeneity of etiologies, and the challenge of attributing deficits to single regions due to network-level brain organization. Additionally, lesion-based inferences can be affected by sample size, imaging quality, and variability in lesion delineation. Despite these caveats, lesion-based methods provide direct causal evidence about brain–behavior relationships that complements functional imaging and electrophysiology.