An fMRI Investigation of Emotional
Engagement in Moral Judgement
Joshua D. Greene, R. Brian Sommerville, Leigh E. Nystrom, John M.
Darley, Jonathan D. Cohen
Ching-Ju (C.J) Tseng & Noralie Krepel
04/14/2014
Abstract
Reason and emotion are likely to play important roles in moral judgement,
however, little is known about their neural correlates, the nature of their
interaction and the factors can modulate their influences.
“We argue that moral dilemmas vary systematically in the extent to which they
engage emotional processing and that these variations in emotional
engagement influence moral judgement” (Greene et al., 2001)
Introduction
Dilemma: the trolley dilemma & the footbridge dilemma
“There is no set of consistent, readily accessible moral principles that captures
people’s intuitions concerning what behavior is or is not appropriate in these
and similar cases” (Greene et al., 2001)
So then, what is it that makes people conclude that in the trolley dilemma it is
acceptable to hit the switch, but in the footbridge dilemma it is not acceptable
to push the stranger off the bridge?
“We maintain that, from a psychological point of view, the crucial difference
between the trolley dilemma and the foodbridge dilemma lies in the latter’s
tendency to engage people’s emotions in a way that the former does not”
(Greene et al., 2001)
Hypothesis: “Some moral dilemmas (those relevantly similar to the footbridge
dilemma) engage emotional processing to a greater extent than others (those
relevantly similar to the trolley dilemma), and these differences in emotional
engagement affect people’s judgement” (Greene et al., 2001)
Predictions
1. During contemplation of dilemmas such as the footbridge dilemma, brain
areas associated with emotion would be more active as compared to
contemplation of dilemmas such as the trolley dilemma.
2. “A pattern of behavioral interference similar to that observed in cognitive
tasks in which automatic processes influence responses” would occur (Greene
et al., 2001).
(3. Individuals that would find pushing the stranger off the bridge in the
footbridge dilemma acceptable exhibit a longer reaction time as a result of
countervailing their emotional response).
Methods
60 practical dilemmas
“moral”
“non-moral”
“non-moral”: taking the train or the bus
“moral”
moral-personal: up close, personal, more emotional (?), footbridge
moral-impersonal: less personal, less emotional (?), trolley
Judge the actions by saying “appropriate” or “inappropriate”
Two experiments: in each experiment, nine participants responded to the 60
dilemmas while undergoing brain scanning using fMRI
Results Experiment 1
Moral-personal
Moral-impersonal*
Medial portions of Brodmann’s Areas (BA) Working memory
BA 9 and 10 (medial frontal gyrus)
BA 46 (middle frontal gyrus, right)
BA 31 (posterior cingulate gyrus)
BA 7/40 (parietal lobe, bilateral)
BA 39 (angular gyrus, bilateral)
Associated with emotion
*Areas associated with working memory have been found to become less
active during emotional processing. In this study, both BA 46 and BA 7/40
were found to become less active during the moral-personal condition as
compared to the moral-impersonal and non-moral condition. However, they
do not say to have found that these areas were associated with moralimpersonal or non-moral judgements. They simply were not associated
with moral-personal judgements.
Experiment 2
Trolley Problem (Moral-impersonal)
Footbridge problem (moral-personal)
Non-moral decisions
• Purpose: to replicate the results of experiment 1 and provide
data concerning reaction time
• Results:
Almost identical to experiment 1, except: No difference in
Brodmann’s Areas 9/10 between moral-impersonal and nonmoral. No difference for BA 46.
• Reaction time
According to the predicting theory,In the moral-personal
condition, responses of “appropriate” is “emotionally
incongruent”, whereas responses of “inappropriate” is
“emotionally congruent”.
• Conclusion
The moral-personal condition had an effect significantly
different from the moral-impersonal & non-moral condition.
Brain areas associated with emotion showed increased
relative activation in the moral-personal condition.
Moral-impersonal judgments resembles more to non-moral
judgments than to moral-personal judgments.
• Discussion
Psychological puzzle: How do people “manage to conclude”
that it is acceptable to sacrifice one for the sake of five in the
trolley dilemma but not in the footbridge dilemma?
Answer:
There are systematic variations in the engagement of emotion
in moral judgment. Pattern of neural activity in emotionrelated brain areas differs between the trolley dilemma and
the footbridge dilemma.
• Philosophical puzzle: Why is it acceptable to sacrifice one
person to save five others in the trolley dilemma but not in
the footbridge dilemma?
Answer:
• Philosophical puzzle: Why is it acceptable to sacrifice one
person to save five others in the trolley dilemma but not in
the footbridge dilemma?
Answer: