Effective connectivity and criminal sentencing decisions: dynamic causal models in laypersons and legal experts

• Published in: Cerebral cortex (New York, N.Y. 1991) Vol. 32; no. 19; pp. 4304 - 4316
• Main Authors: Asamizuya, Takeshi, Saito, Hiroharu, Higuchi, Ryosuke, Naruse, Go, Ota, Shozo, Kato, Junko
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 19.09.2022
• Subjects: Original; functional connectivity; dynamic causal modeling; insula; prefrontal cortex; neurolaw
• ISSN: 1047-3211; 1460-2199; 1460-2199
• DOI: 10.1093/cercor/bhab484

Abstract This magnetic resonance imaging study is designed to obtain relevant implications for criminal justice and explores the effective connectivity underlying expertise. Laypersons and experts considered sentences for remorseful and remorseless defendants, respectively, with and without mitigation, in hypothetical murder cases. Two groups revealed no differential activation. However, dynamic causal modeling analysis found distinct patterns of connectivity associated with subjects’ expertise and mitigating factors. In sentencing for remorseful defendants, laypersons showed increased strength in all bidirectional connections among activated regions of Brodmann area (BA) 32, BA23, the right posterior insula, and the precuneus. In contrast, legal experts sentenced based on mitigation reasoning, showed increased strength only in the bidirectional connection between the insula and the precuneus. When sentencing for remorseless ones without mitigation, both laypersons and experts increased the connection strength, but with reverse directionality, between regions; legal experts strengthened connectivity from BA10 to other regions, that is, the right anterior insula and BA23, but the directionality was reversed in laypersons. In addition, the strength of connection to BA32 and BA10 was correlated with changes in punishments by mitigating factors. This is a crucial result that establishes the validity of the connectivity estimates, which were uninformed by the independent (behavioral) differences in the severity of punishment.