Functions of primate amygdala neurons in economic decision-making
The amygdala, a collection of nuclei in the temporal lobe, is key brain structure for reward and emotion with classical functions in social behaviors. Recent evidence suggests that primate amygdala neurons participate in advanced reward-guided behaviors, including economic decision-making. Using single-neuron recordings in monkeys performing a sequential decision task, we showed that amygdala neurons signal the monkeys’ upcoming economic choices (Grabenhorst et al., 2012), the progress within a multi-step choice sequence (Grabenhorst et al., 2016), and the monkeys’ internal plans to obtain distant reward goals (Hernadi et al., 2015). Despite these advances, it remains unclear how the amygdala’s decision function is related to its classical role in social behavior. To address this question, I will present new data from amygdala neurons recorded as two monkeys made economic decisions in a social setting that allowed them to observe and learn from each other. During observational learning, amygdala neurons signalled the reward values of specific visual choice objects, irrespective of whether value derived from own experience or observation. These neurons often showed dynamic coding transitions: initial object-value signals subsequently predicted either the monkey’s own choices or the choices of the partner. Such value-to-choice transitions constitute a neuronal signature of decision-making predicted on computational grounds and previously observed in amygdala neurons in non-social decisions (Grabenhorst et al., 2012). These data suggest that amygdala neurons derive object values from observational learning and simulate the decision computations of social partners. These findings link traditional concepts of amygdala social functions with recent concepts of amygdala decision functions.
Prediction of economic choice by primate amygdala neurons. PNAS (2012)
Primate amygdala neurons evaluate the progress of self-defined economic choice sequences. Elife (2016)
Planning activity for internally generated reward goals in monkey amygdala neurons. Nature Neuroscience (2015)