White matter disconnection in acquired criminality

Structural brain imaging is increasingly introduced as evidence in criminal trials. A key imaging abnormality identified in criminal populations is alteration to the right uncinate fasciculus but it remains unclear whether these changes play a causal role in criminal behavior. Lesion studies of acquired criminality offer the opportunity to assess the causal role of focal disruption of specific white matter connections in criminal behavior. We studied lesion locations of focal brain damage associated with new onset criminal behavior compared to lesions associated with 21 diverse neuropsychiatric symptoms. First, we analyzed the intersection of lesion locations with an atlas-based right uncinate fasciculus. Second, we assessed the intersection of lesion locations with all white matter tracts from this atlas. Third, we performed a connectome-based analysis of all possible white matter connections with each lesion location, without a priori assumptions regarding specific tracts. We repeated all analyses limited to subjects who committed violent crimes. Lesions associated with criminality intersected the right uncinate more than lesions associated with other neuropsychiatric symptoms (p = 4.78 × 10^-8). Compared to other tracts, the right uncinate fasciculus was the tract most strongly associated with lesion-induced criminality followed by the forceps minor. An unbiased connectome-based analysis confirmed these findings. Among subjects who committed violent crimes the right uncinate was the key tract identified. Lesions associated with criminality intersect the right uncinate fasciculus more than other lesions and more than other white matter tracts. Damage to the right uncinate may play a causal role in criminal behavior, especially violent crime.