Structural neuroimaging and the antisocial brain: Main findings and methodological challenges

A series of neuroimaging studies have reported structural differences in several subcortical and frontal systems in individuals with stable antisocial behavior (sASB). Specifically, differences have been observed in the prefrontal and temporal cortices (e.g., amygdala and hippocampus). However, the sASB population is typically characterized by co-occurring hyperactivity-inattention symptoms and low cognitive ability. These nuisance variables are likely to complicate the interpretation of findings regarding structural differences associated with sASB. The way in which each study deals with these variables influences the conclusions that can be drawn about the brain structure and function of children and adults with sASB. This article briefly reviews the extant literature in this field before considering two approaches that may be used to deal with comorbidities conceptualized as nuisance variables--namely, the analysis of covariance (ANCOVA) and the matched-group design. Then, the authors illustrate, with their own data, checks that may be performed to ensure the validity of results using ANCOVA.