A new meta-analysis just appeared in the Journal of Moral Education on the neural correlates of moral judgment and moral sensitivity in parts of the brain associated with self-hood (full paper available here). Here are some of the key findings:
The default mode network regions were commonly associated with moral functions across diverse domains of moral tasks...The results showed that during [moral] judgment tasks, the ventromedial and dorsomedial prefrontal cortices, temporoparietal junction, middle temporal gyrus and connected superior temporal sulcus, middle occipital gyrus, temporal pole, fusiform gyrus, inferior temporal gyrus and precuneus were activated. In the moral sensitivity condition, the dorsomedial, ventromedial and ventrolateral prefrontal cortices, cingulate gyrus, temporoparietal junction, orbitofrontal cortex, middle temporal gyrus, middle occipital gyrus, fusiform gyrus, lingual gyrus, temporal pole, inferior temporal gyrus, precuneus, cuneus and amygdala were activated.
Here is each individual brain region found to be involved in 'moral judgment' (i.e. making decisions in response to moral problems), along with some of each region's known or hypothesized functions (content and quotations taken from hyperlinked material):
- Delaying immediate rewards for possible future rewards. (Ventromedial PFC)
- Recognition of a single situation from multiple perspectives (Temporoparietal junction)
- Memory formation, including visual memories (Cingulate gyrus & Lingual gyrus)
- Sadness and sense of self-esteem (Cingulate Gyrus)
- Inhibition and gambling avoidance (Cuneus)
- Emotional learning, emotional intelligence, fear and anxiety, etc. (Amygdala)
Here are some addtional related facts:
- Temporopartietal junction (rTPJ):
- Larger rTPJ's are linked to altruism.
- Better interconnected rTPJ's reduce bias for in-groups.
- rTPJ stimulation improves taking other people's perspectives.
- rTPJ inhibition simultaneously diminishes altruism and prudential concern for one's own future selves.
- Some comments on these findings:
- 'For a long time, people have speculated that we use the same mechanisms to reason about other people as about our hypothetical selves...this new study fits really well.'
- "...neuroimaging is notoriously fickle, producing many false positives and false negatives. Yet every group that sought to identify brain regions implicated in ToM got essentially the same answer; and in study after study, we still do.'
- 'Empathy depends on your ability to overcome your own perspective, appreciate someone else’s, and step into their shoes. Self-control is essentially the same skill, except that those other shoes belong to your future self—a removed and hypothetical entity who might as well be a different person. So think of self-control as a kind of temporal selflessness. It’s Present You taking a hit to help out Future You.'
- Psychopaths, who are notable for wantonly violating moral norms and not recognizing the normative force of 'moral reasons', demonstrate (a) impulsivity (Hare 1999), (b) lack of concern for consequences of their past actions (ibid.), (c) lack of concern for future consequences (Hart & Dempster 1997), and (d) underdeveloped brain regions related to 'mental time-travel' (the capacity to imagine possible pasts and futures - Stuss et al. 1992).
- Children and adolescents, commonly recognized as having diminished moral responsibility, display (a) impulsivity (Baumeister et al 2001), (b) inability to think through the future consequences of their actions (ibid.), and (c) underdevelopment in the same brain regions associated with mental time-travel as psychopaths (Casey et al. 2008; Giedd et al 1999; Kennett & Matthews 2009).
- Impulsivity/present-focusedness is one of the strongest individual-level predictors of criminal activity (Van Gelder et al 2013, Hirschi 2004, Gottfredson & Hirschi 1990; and Wilson & Hernstein 1985).
- Self-control (delaying present satisfaction for future reward) is positively related to health, wealth, and success.
- Experimental interventions stimulating future-directed mental time-travel (prompting respondents to imagine the future or interact with a virtual reality depiction of their older self) have been found to simultaneously augment both prudential and moral responses--e.g. saving money for oneself and unwillingness to sell stolen goods (Ersner-Hershfield, Wimmer, & Knutson 2009; Hershfield et al. 2011; Van Gelder et al. 2013).
Readers may note connections to ideas developed here (above citations located therein).
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