Riken Research (text) has news of a paper by S. Suzuki and others, Learning to simulate others’ decisions, in Neuron.

‘Theory of mind’ is how the ability to predict the actions of others is known. In effect we model their thoughts. Does this simulation of thought use the same neural process as our own thoughts?

(The researchers) used functional magnetic resonance imaging to scan participants’ brains while they performed two simple decision-making tasks. In one, they were shown pairs of visual stimuli and had to choose the ‘correct’ one from each, based on randomly assigned reward values. In the second, they had to predict other people’s decisions for the same task.

The researchers confirmed that the participants’ own decision-making circuits were recruited to predict others’ decisions. The scans showed that their brains simultaneously tracked how other people behaved when presented with each pair of stimuli, and the rewards they received.

“We showed that simple simulation is not enough [to predict other peoples’ decisions], and that the simulated other’s action prediction error is used to track variations in another person’s behavior”

The two steps here appear to be (1) what would be the right decision if I was making that decision, and (2) how does the other person differ in their patterns of action from me.

Here is the abstract:

A fundamental challenge in social cognition is how humans learn another person’s values to predict their decision-making behavior. This form of learning is often assumed to require simulation of the other by direct recruitment of one’s own valuation process to model the other’s process. However, the cognitive and neural mechanism of simulation learning is not known. Using behavior, modeling, and fMRI, we show that simulation involves two learning signals in a hierarchical arrangement. A simulated-other’s reward prediction error processed in ventromedial prefrontal cortex mediated simulation by direct recruitment, being identical for valuation of the self and simulated-other. However, direct recruitment was insufficient for learning, and also required observation of the other’s choices to generate a simulated-other’s action prediction error encoded in dorsomedial/dorsolateral prefrontal cortex. These findings show that simulation uses a core prefrontal circuit for modeling the other’s valuation to generate prediction and an adjunct circuit for tracking behavioral variation to refine prediction.