Why are some types of behaviour deemed wrong or good? Much of the philosophical work dedicated to this question has been focused on what could be called its metaphysical dimension: How can we determine if some act is good or bad by necessity, and should therefore be considered good or bad by all people? Recently, however, a growing number of researchers have begun to look into its neurocognitive dimension: How does the human brain decide whether or not a behavioural act is good or bad? Two researchers have more than anyone pioneered this approach: a philosopher-cum-psychologist, Joshua Greene, and Jorge Moll, a neuroscientist. Both have conducted a number of imaging experiments trying to illuminate which processes takes place when we make an ethical decision.
Now Moll, together with renowned neuroscientist Jordan Grafman, has published an interesting review of this research so far, which can be found in the October issue of Nature Reviews Neuroscience. Their basic proposal is that ethical decision-making is the result of the integration of processesing in three different brain systems: the prefrontal cortex, the temporal lobe, and the limbic system (and/or the reward system). They call this the “event-feature-emotion” complex. In this scheme, PFC computes event-structures (a Grafman term) and social values; the temporal lobe computes perceptual and functional features relevant for social reasoning; and the emotional system computes motive states. An example from the paper illustrates their reasoning. If you come across an orphan child, the “feature” system will inform the brain of the child’s display of sadness, and imbue knowledge of what it means to be helpless. The “event-structure” system will predict the sad future of a child living without parental support, and the “motive” system will activate an emotional response to this cognitive processing. The end result will be something like a complex conceptual and emotional integration: This child is in a state of distress; it will not survive without its parents; this situation makes me sad or angry, and I should do something to help alleviate it. It is the right thing to do.
Moll and Grafman’s model is hardly the last word on ethical decision-making. But it is exciting to see that some progress is being made in understanding how the moral brain works, seeing as the first neuroethics experiment was only published in 2001.