How do we decide what to eat? In humans, the reward value derived from sensory and nutritional food components motivates sophisticated forms of eating behaviour, including consumption-planning, decision-making, and social influences on food choice. Specific nutrients—such as fats, sugars, and their sensory qualities—are particularly effective rewards that drive such behaviours and contribute to overeating and obesity. Because neurons in the brain’s reward system set the goals for behaviour, we aim to understand how such reward neurons process specific food components to guide planning and decision-making. We focus on the amygdala, a key component of the reward system that is implicated in such diverse conditions as depression, autism, and obesity. Our recent data indicate that beyond basic reward functions, amygdala neurons participate in advanced reward-guided behaviours, including economic decision-making and social learning.
We study the mechanisms for eating behaviour and reward-based decisions in both individual neurons and functional brain systems. We conduct single-neuron recordings in animals performing behavioural tasks for nutrient-defined food rewards. These experiments identify the precise information processing by neurons in key reward structures, including the amygdala. In parallel, we conduct closely related human neuroimaging studies to translate and extend the single-neuron data to human brain systems, real-life eating phenotypes, and inter-individual differences. Our work benefits from collaborations with experimental and computational neuroscientists in Cambridge and abroad, in particular the group of Professor Wolfram Schultz at the Department of Physiology, Development and Neuroscience, with which we are associated, and with Professors Sadaf Farooqi and Paul Fletcher at the IMS. Our broader goal is to uncover basic neurophysiological reward mechanisms that underlie human eating behaviour and thereby to lay foundations for clinical studies in obesity.
Grabenhorst, F.*, Hernadi, I.*, and Schultz, W. (2016). Primate amygdala neurons evaluate the progress of self-defined economic choice sequences. Elife 5. (*Joint first authors). PMID:27731795. PMCID:PMC5061547
Zangemeister, L.*, Grabenhorst, F.*, and Schultz, W. (2016). Neural Basis for Economic Saving Strategies in Human Amygdala-Prefrontal Reward Circuits. Curr Biol: CB 26, 3004-3013. (*Joint first authors). PMID:27773572. PMCID:PMC5130697
Tsutsui, K.*, Grabenhorst, F.*, Kobayashi, S., and Schultz, W. (2016). A dynamic code for economic object valuation in prefrontal cortex neurons. Nature Commun 7, 12554. (*Joint first authors). PMID:27618960. PMCID:PMC5027248
Hernadi, I.*, Grabenhorst, F.*, and Schultz, W. (2015). Planning activity for internally generated reward goals in amygdala neurons. Nature Neurosci 18, 461-469. (*Joint first authors). PMID:25622146. PMCID:PMC4340753
Grabenhorst, F., and Rolls, E.T. (2014). The representation of oral fat texture in the human somatosensory cortex. Hum Brain Mapp 35, 2521-2530. PMID:24038614
Grabenhorst, F.*, Hernadi, I.*, and Schultz, W. (2012). Prediction of economic choice by primate amygdala neurons. Proc Natl Acad Sci U S A 109, 18950-18955. (*Joint first authors). PMID:23112182. PMCID:PMC3503170
Grabenhorst, F., and Rolls, E.T. (2011). Value, pleasure and choice in the ventral prefrontal cortex. Trends Cogn Sci 15, 56-67. PMID:21216655
Grabenhorst, F., Rolls, E.T., Parris, B.A., and D’Souza, A. (2010). How the brain represents the reward value of fat in the mouth. Cereb Cortex 20, 1082-1091. PMID:19684248