The role of social norms, empathy, and religiosity in assisted dying decisions: an fMRI study.

Résumé

Medical assistance in dying (MAiD) is gaining legal and social acceptance; yet it remains ethically controversial and challenging for healthcare professionals. This functional MRI study examines how social norms and empathy influence MAiD decisions in 59 Australian medical students while evaluating hypothetical assisted-dying scenarios. Participants' decisions generally aligned with the legal framework. MAiD was approved when eligibility criteria were met (normative cases) and denied when they were not (nonnormative cases). Nonnormative scenarios elicited greater activation in frontoparietal brain regions involved in response selection and inhibition, consistent with increased decision difficulty. These scenarios elicited heightened activity in the precuneus, temporoparietal junction, and angular gyrus, along with stronger functional connectivity between the anterior hippocampus and the precuneus, suggesting greater reliance on memory retrieval and mentalizing. Normative scenarios were associated with increased amygdala activity, particularly among less religious participants, suggesting a role for negative affective salience. Greater activity in the ventromedial prefrontal cortex, and connectivity between the anterior cingulate cortex and this region, suggest positive feelings related to compassion when a clinician can legally approve an assisted dying request. Normative scenarios were also associated with reduced connectivity between the anterior cingulate cortex and the anterior insula, particularly in those with higher trait affective empathy, suggesting that doctors might feel a reduction in their patients' pain. The findings provide the first empirical evidence of the neural mechanisms underlying decision-making in bioethical cases involving death as the outcome, highlighting distinct contributions and potential risk factors for medical practitioners in normative and nonnormative MAiD clinical situations.