Neuron
Volume 95, Issue 1, 5 July 2017, Pages 70-77.e3
Journal home page for Neuron

Report
Distinct Roles for the Amygdala and Orbitofrontal Cortex in Representing the Relative Amount of Expected Reward

https://doi.org/10.1016/j.neuron.2017.06.012Get rights and content
Under an Elsevier user license
open archive

Highlights

  • Monkeys’ behavior tracked the relative reward magnitude predicted by stimuli

  • Neurons in orbitofrontal cortex (OFC) and the amygdala encode this relative magnitude

  • Relative-magnitude-coding neurons in OFC update faster than their amygdala counterparts

  • Relative-magnitude-coding neurons in OFC but not in the amygdala integrate reward history

Summary

The same reward can possess different motivational meaning depending upon its magnitude relative to other rewards. To study the neurophysiological mechanisms mediating assignment of motivational meaning, we recorded the activity of neurons in the amygdala and orbitofrontal cortex (OFC) of monkeys during a Pavlovian task in which the relative amount of liquid reward associated with one conditioned stimulus (CS) was manipulated by changing the reward amount associated with a second CS. Anticipatory licking tracked relative reward magnitude, implying that monkeys integrated information about recent rewards to adjust the motivational meaning of a CS. Upon changes in relative reward magnitude, neural responses to reward-predictive cues updated more rapidly in OFC than amygdala, and activity in OFC but not the amygdala was modulated by recent reward history. These results highlight a distinction between the amygdala and OFC in assessing reward history to support the flexible assignment of motivational meaning to sensory cues.

Keywords

amygdala
OFC
orbitofrontal cortex
motivation
range adaptation
relative reward
reward history
Pavlovian learning

Cited by (0)

5

Present address: Champalimaud Research, Champalimaud Centre for the Unknown, Avenida de Brasília, Lisbon 1400-038, Portugal

6

Present address: Sorbonne Universités, UPMC Univ. Paris 06, Inserm, CNRS, Institut du Cerveau et de la moelle épinière (ICM) – Hôpital Pitié-Salpêtrière, Boulevard de l’hôpital, F-75013, Paris, France

7

These authors contributed equally

8

Lead Contact