Hippocampal Damage Increases Deontological Responses during Moral Decision Making

Area of Science:

• Neuroscience
• Cognitive Psychology
• Moral Philosophy

Background:

• Complex moral decision-making is linked to the ventromedial prefrontal cortex (vmPFC).
• vmPFC damage results in more utilitarian judgments and decreased emotional arousal.
• The vmPFC has strong anatomical and functional connections with the hippocampus.

Purpose of the Study:

• To investigate how selective bilateral hippocampal damage affects moral decision-making.
• To compare the moral decision-making patterns of hippocampal-damaged patients with those of vmPFC-lesioned patients and controls.

Main Methods:

• Utilized a classic moral dilemmas paradigm with patients exhibiting selective bilateral hippocampal damage.
• Collected skin-conductance data to measure emotional arousal during moral decision-making tasks.
• Compared the moral judgments and emotional responses of hippocampal-damaged patients to control participants.

Main Results:

• Hippocampal-damaged patients showed significantly fewer utilitarian judgments and favored deontological responses.
• Patients with hippocampal damage exhibited increased emotional arousal, basing decisions on emotional instinct.
• Control participants integrated emotional responses, consequence visualization, and rational re-evaluation.

Conclusions:

• Hippocampal damage leads to a deontological approach to moral decision-making, contrasting with the utilitarian approach seen in vmPFC damage.
• Hippocampal lesions may impair the visualization of consequences, making emotional responses dominant.
• The findings highlight the complementary roles of the hippocampus and vmPFC in moral decision-making.