PhD on Confidence in Collective Decision-Making

This PhD will investigate links between neuroscience, social insect collective behaviour, and decision theory. Theories of optimal decision-making have successfully been applied to individual-level decisions, both in explaining data from experimental subjects, and in analysing the optimal performance of neurobiologically realistic models. A key feature of many such models is that sensory evidence is compared against some internal threshold in determining what choice to make. The magnitude of this difference could be thought of as a measure of confidence in the decision; if the evidence was close to the threshold then an error may have been made and confidence in the decision should be low, but if the evidence was way above the threshold, then an error is unlikely and decision confidence should be high. Decision confidence has proved to be useful in understanding behaviour and neural activity in individuals [1]. At the same time, recent complementary work has applied optimality theory developed for neural models to the collective behaviour of social insects, such as ants and honeybees, when searching for a new potential nest site [3]. There are many similarities between the interaction patterns of social insect colonies, and neural populations in the brain [2][4]. The proposed PhD project will further extend these analogies, by examining the potential role of individual and collective decision-confidence in models of house-hunting by ant and honeybee colonies.

The successful candidate will have a background in a numerate discipline such as mathematics, computer science, or physics, ideally with some knowledge of probability, statistics and decision theory. A demonstrated interest in biology is a definite advantage. They will become part of the newly established Behavioural and Evolutionary Theory Lab at the University of Sheffield, Department of Computer Science, under the direction of Dr James Marshall. It is anticipated that there will be opportunities for interaction with empirical social insect researchers to inform and test the theory developed during the project.

About the Behavioural and Evolutionary Theory Lab
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The Behavioural and Evolutionary Theory Lab is an interdisciplinary collection of individuals interested in how and why behaviours evolve. We are interested in behaviours and behavioural mechanisms, and their evolutionary function. We apply a range of theoretical approaches, from mathematics and statistics, decision theory, computer science, and physics. Particular topics of interest are currently the evolution of social behaviour, such as altruism and cooperation, and optimal decision-making mechanisms in groups, such as social insects, and in individuals. The Lab is part of the Department of Computer Science, University of Sheffield, and is physically based in the interdisciplinary Kroto Research Institute.

Applications are invited from UK home students and EU citizens. Fees and a stipend will be paid for the duration of the studentship. Apply online or contact Dr Marshall if you require further information. Closing date: Feb 27th.

References
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[1] Kepecs, A. et al. (2008) Neural correlates, computation and behavioural impact of decision confidence. Nature 455, 227-231.
[2] Lindhart, E. (2009) Ants and neurons. SEED Magazine (http://seedmagazine.com/content/article/ants_and_neurons/)
[3] Marshall, J.A.R. et al. (2009) On optimal decision-making in brains and social insect colonies. Journal of the Royal Society: Interface 6, 1065-1074.
[4] Marshall, J.A.R. and Franks, N.R. (2009) Colony-level cognition. Current Biology 19, R395-R396.

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James A. R. Marshall
Department of Computer Science
University of Sheffield
http://staffwww.dcs.shef.ac.uk/people/J.Marshall/