Dr Amelia Hunt (University of Aberdeen) https://www.abdn.ac.uk/psychology/people/profiles/a.hunt
Dr Rama Chakravarthi (University of Aberdeen) https://homepages.abdn.ac.uk/rama/pages/index.html
Variability is a fundamental property of complex natural systems. It is unsurprising that human behaviour, being a product of these systems, would be difficult to predict. However, research on human behaviour tends to treat variability as noise to be minimised and removed, relying instead on averages to describe distributions of data. This can be an effective approach to finding stable patterns that inform models and theories. But averages present an incomplete, and sometimes misleading, view. This is particularly the case when it comes to variability in human decisions. A fundamental, yet unsettled, question is the extent to which decisions can be thought of as rational. When an optimal decision rule exists, any variation in decisions will be detrimental to maximizing gains. Despite this, variation remains a persistent feature of choice behaviour: classic research in rats  has suggested that making variable decisions in the choice-points of a maze is characteristic of a healthy nervous system, in contrast to brain-damaged rats, who tend to perseverate. The suggested purpose of this variation is exploration of the consequences of a range of different choices. Variable responses may therefore present a powerful default strategy when the situation is unfamiliar or when the conditions are dynamic. Healthy humans exhibit highly variable responses when presented with the same decision problem [e.g. 2], but surprisingly little is known about the stability and function of choice variability in humans. The proposed project fills this gap. We will use eye movements as a model for choice; choosing where to fixate is a simple and frequent decision, each of which is followed by an important, measurable consequence (i.e., the acquisition of new visual information). Our recent findings demonstrate that eye movements can be optimal or variable, depending on the context . Building on this, this project tests the hypothesis that variation in selecting eye movements can itself be a rational strategy, ensuring that the visual system obtains information from new locations, rather than repeating previous sequences. The planned components: 1) systematically examine which specific conditions lead to variable vs optimal modes of eye movement selection 2) evaluate the prediction that variable behaviour is optimal for the conditions in which it is observed, and 3) explore and describe the distribution of variability to better understand how it is generated and constrained. Eye-movement paradigms will be combined with computational and neurophysiological (EEG) approaches to comprehensively assess the question of optimality of variations in decision-making. Being able to predict eye movements, in addition to shedding light on the question of the utility of variation, also has practical applications for a wide range of settings in which it is critical to anticipate what information in a given scene will likely be sampled. Crucially, we have previously established that results from eye movement choices can generalize to more complex and deliberative decisions, suggesting that the conclusions drawn from this line of work could have broad implications for how humans make choices.
Please send your completed EASTBIO application form, along with academic transcripts to Alison McLeod at [Email Address Removed]. Two references should be provided by the deadline using the EASTBIO reference form. Please advise your referees to return the reference form to [Email Address Removed].
This 4 year PhD project is part of a competition funded by EASTBIO BBSRC Doctoral Training Partnership http://www.eastscotbiodtp.ac.uk/how-apply-0. This opportunity is open to UK and International students and provides funding to cover stipend and UK level tuition (limited funding is available to provide international tuition fees). Please refer to UKRI website and Annex B of the UKRI Training Grant Terms and Conditions for full eligibility criteria.
Candidates should have (or expect to achieve) a minimum of a 2:1 UK Honours degree, or the equivalent qualifications gained outside the UK, in a relevant subject.
 Krechevsky (1937). J. Compar. Psychol. 23: 121-138;  Clarke, ADF and Hunt, AR (2016), Psychol Sci 27: 64-74;  Nowakowska, A et al., (2020), PsyArXiV.