Every day, we are faced with a multitude of decisions that shape our lives, from the mundane choices of what to have on our breakfast toast to the life-altering ones that determine our careers. While some decisions may seem trivial, the cumulative effect of our choices influences the paths our lives will take. Making optimal decisions is therefore of paramount importance. 

In familiar scenarios, we often rely on past experiences and repeat actions that have been rewarded. After all, if the cheese was delightful yesterday, why not choose it again? Yet, there are countless instances where we find ourselves in new situations, devoid of specific prior knowledge to guide us. In such situations, we might adapt our decision-making based on behaviours we see in others (Garvert et al. Neuron 2015). Alternatively, we rely on the structure that exists in the world and exploit the fact that we are likely to have made similar experiences in the past. This kind of behaviour requires a representation of relationships between events we experience. We demonstrated that the hippocampus plays a critical role in this kind of situation and organises relationships in cognitive maps (Garvert et al. eLife 2017, Zheng et al. bioRxiv 2022). These maps can then be used to guide generalisation in new decision-making situations (Garvert et al. Nat Neurosci 2023). However,  the ever-changing external world and our behavioral policies need to be flexibly adjusted in response to new information and unexpected outcomes if we want to maximise rewards. How does the brain do this?

To answer this and similar questions, we study the neural representations and computations underlying learning and decision-making by employing multidisciplinary approach encompassing behavioural experiments, human neuroimaging techniques, and computational modeling. Our primary focus lies in understanding how the brain constructs, updates, and uses models of the world to guide behaviour. To probe the neural underpinnings, we leverage techniques that enable us to index neural representations in the human brain (Barron, Garvert and Behrens, 2016). In this way, we aim to uncover the intricate processes that shape decision-making, shedding light on the mechanisms that drive our choices.

Our curiosity extends beyond the realm of normal cognition. We are also deeply intrigued by how these processes can go awry in psychiatric disorders (Thomas et al. 2022). By studying inter-individual differences in behaviour and brains, we hope to gain insights into the neural mechanisms that underlie cognition and ultimately pave the way for improved and more targeted treatments of psychiatric disorders.

Join us on this journey as we unravel the mechanisms of decision-making, explore the intricacies of neural representations, and investigate how these processes can be disrupted in psychiatric disorders. Together, we aim to deepen our understanding of the human mind and forge new pathways towards mental well-being.