Neural mechanisms of flexibility, motivation and learning in ecological environments

Lead Research Organisation: University of Oxford
Department Name: Psychiatry

Abstract

I am a neuroscientist and psychologist interested in how our brain enables us to make decisions and motivates us to engage with our environment. To tackle this, I use a variety of brain imaging tools, such as magnetoencephalography (MEG) and magnetic resonance imaging (MRI).

While a lot of work has gone into understanding the parts of the brain involved in simple consumer choices, such as deciding what food to buy at a supermarket, we know remarkably little about other kinds of real-life decision making. One example for the kinds of decisions is goal-directed search. Imagine you are foraging for mushrooms or other food in a forest. It might not seem to you as if you making many deliberate decisions, but such search requires many features to be considered. For example, is the current patch of the forest a good place for finding mushrooms or are there any other items of value there? If not, where should I go next and how long should I search there? As this is evolutionarily speaking a very important decision, our brains presumably evolved to be good at my current research questions take inspiration from this kind of ecological challenge. For example one of my research topics is about more general decisions such as deciding what environment to be in and how long for.

My other major research question is about understanding decision flexibility. More specifically, I want to understand how the brain identifies when to make a decision in the first place and under what decision rules or strategies. For example, when buying a house one could make extensive lists and compare each house carefully across many dimensions, ranking them by relevance, or alternative act on a proximal sense of how much one likes a house overall, particularly compared to the other houses on the market and pick one that is sufficiently above the alternatives to be satisfactory. At first glance the first strategy might seem superior, but for decisions with many unknowns the later, might be more resource efficient and produce overall better outcomes. Even in the example of buying a house, it can be quite excruciating to try and find an appropriate way to combine all possible factors to consider. How for example, to you decide how much larger garden shed is worth compared to a smaller kitchen and a worse location? What specifically interests me is not only a specific decision-strategy for buying a house, but also how people are capable of changing their approach to a decision problem, i.e. go from one approach to another, if the initial strategy has proven to be insufficient or circumstances change.

Both my research questions are essential because if we want to understand people's remarkable capacity for responding adaptively, we need to understand how they decide to approach a specific decision problem. It might seem daunting to try to relate the activity of many millions of neurons to specific choices an individual makes, but over the last couple of decades increasingly sophisticated approaches have been developed to relate aggregate activity of many neurons interacting with each other to human and animal behaviours. I specifically use simple cognitive and computational models to make predictions of how brain regions react to different information and under different conditions.

For the fellowship I work at the Oxford Centre for Human Brain Activity (OHBA), part of the Department of Psychiatry at the University of Oxford, which focuses on developing and applying new methods and tools in order to understand how the human brain supports higher cognition. I collaborate with other researchers to understand the effects of aging on the measures of behavioural flexibility to understand whether they could be used to further support healthy aging. I also collaborate with clinical researchers to improve our basic understanding, diagnosis and treatment of psychological illnesses such as depression.

Technical Summary

Every day people make many kinds of decisions. However, decision neuroscience has mostly sidestepped questions of how participants dynamically assess whether to engage with a decision in the first place and of whether a decision strategy is consistent with more overarching goals. However, in real life these higher-order decisions are crucial, affecting not just preferences but how much energy to invest and for how long. The overall aim of my work is to understand ecological voluntary behaviours. Specifically, I will focus at two issues emerging under more naturalistic conditions - setting motivational states by tracking changing environments and environment-driven decision strategy flexibility.
The theories and computational models underlying my proposal are inspired by both biology and psychology and grounded in novel ecological ideas I have put forward (Kolling; 2016 NN, 2015 Cell). I am particularly interested in how people use past reward experiences to predict the future. Specifically, I want to understand how expectations of reward trends are used in order to make ecological decisions such as betting on the stock market. Second, I have previously identified the frontal pole in counterfactual reasoning (Scholl & Kolling, 2015 JN) and implementing long-term strategies (Kolling 2014, Neuron). I believe it also plays a role in allowing flexible contextualization of decision strategies and their competition. Therefore I focus on FPC in investigating the neural interactions of distinct decision circuits in changing environments to understand how people adapt their decision strategy dynamically as overall incentives or resource availability change.
For both projects it is necessary to measure neural activity in a highly temporally resolved manner. I will therefore use different types of electrophysiological measurements, specifically MEG in humans and single-unit electrophysiology in non-human primates. For spatial resolution I will use fMRI.

Planned Impact

Motivation and an ability to act flexible to changing circumstances are essential to human flourishing throughout a person's lifespan. My research is aiming to understand the cognitions involved, find computational models and precise measurements describing them and relate such cognitive models to their underlying brain mechanisms. While, this work addresses a fundamental aspect of human behaviour and is therefore of significant scientific interest. However, beneficiaries of my research are not just within the wider scientific community but also beyond.

Firstly, I will develop computerized cognitive tasks, which can map individual differences of meaningful metrics of motivation and behavioural flexibility across the lifespan and have the potential to find associations between cognitive styles and health. Furthermore, a longer-term goal of mine is finding ways to increase behavioural flexibility through training on computerized tasks or brain stimulation methods.

While both of those goals are still some time off, the first step for meaningful improvement of peoples life's, is a deep understanding of the underlying processes in naturalistic settings as well as characterization of differences between people. Specifically my work would allow clinical researchers to build on my findings to look at other problems of motivation and behavioural flexibility, such as in psychological disorders. In fact, I have already published articles with clinical researchers and have further active collaborations. To make a wider use of my ideas as easy as possible, I am going to be actively engaged in making toolboxes allowing my work to be more broadly used by other researchers. Additionally, by mapping out larger populations according to precise measurements of motivational features and ability to adapt to change, epidemiological studies can find important factors, which could subsequently help shaping public policies in the longer-term future.

Additionally, I plan to inform the wider public about basic aspects of my research through lay person descriptions of my work on my personal website, involvement in public engagement sessions at my University and by giving interviews to journalist about my work. In fact several news outlets have previously reported on my findings (e.g. on the Big Think web portal, in a popular science web blog from the dutch public broadcasting system called "De Kennis van Nu" or in popular Science books such as "The Athletic Brain". Clinical work inspired by my work on flexible risk taking has been covered in the "Daily Mail"). Hopefully understanding of psychological processes can reduce the stigma and increase public understanding of problems of individuals affected by a specific disorder.

Publications

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