Effective connectivity of brain regions underlying third-party punishment: Functional MRI and Granger causality evidence

ABSTRACT

Third-party punishment (TPP) for norm violations is an essential deterrent in large-scale human societies, and builds on two essential cognitive functions: evaluating legal responsibility and determining appropriate punishment. Despite converging evidence that TPP is mediated by a specific set of brain regions, little is known about their effective connectivity (direction and strength of connections). Applying parametric event-related functional MRI in conjunction with multivariate Granger causality analysis, we asked healthy participants to estimate how much punishment a hypothetical perpetrator deserves for intentionally committing criminal offenses varying in levels of harm. Our results confirmed that TPP legal decisions are based on two domain-general networks: the mentalizing network for evaluating legal responsibility and the central-executive network for determining appropriate punishment. Further, temporal pole (TP) and dorsomedial prefrontal cortex (PFC) emerged as hubs of the mentalizing network, uniquely generating converging output connections to ventromedial PFC, temporo-parietal junction, and posterior cingulate. In particular, dorsomedial PFC received inputs only from TP and both its activation and its connectivity to dorsolateral PFC correlated with degree of punishment. This supports the hypothesis that dorsomedial PFC acts as the driver of the TPP activation pattern, leading to the decision on the appropriate punishment. In conclusion, these results advance our understanding of the organizational elements of the TPP brain networks and provide better insights into the mental states of judges and jurors tasked with blaming and punishing legal wrongs.

KEYWORDS:

• Third-party punishment
• social cognition
• prefrontal cortex
• temporal pole
• effective connectivity

Acknowledgement

The authors are grateful to E. Wassermann for performing the neurological exams.

Disclosure statement

The authors are unaware of any conflicts of interest, financial, or otherwise.

Supplemental data

Supplemental data for this article can be accessed here.

Additional information

Funding

The work was supported by the Intramural Research Program of the CNS/ NINDS/ NIH.