Global St Andrews and Bonn Doctoral Scholarship - Psychology and Neuroscience

Project

One of the most fascinating features of neural circuits in the brain is their ability to constantly predict what will happen next. For instance, when we move, our brains expect certain sights and sounds that indicate what we are doing. Learning happens when reality differs from those expectations: the brain notices the mismatch and updates its predictions, allowing us to adapt to changing circumstances. Despite decades of research, fundamental questions remain. How does the brain decide when to change its predictions, and how does it adapt rapidly to surprises without overwriting stable knowledge? Neuromodulators, molecules that change neuronal function over longer timescales, are thought to be key to this process, but it is unclear how.

This highly collaborative project will combine modelling and experiment to address these questions, leveraging the complementary expertise within Bonn and St Andrews. We will, first, use computer models to generate precise hypotheses, and then test them in larval zebrafish using modern imaging and targeted perturbations.

Rationale and hypothesis

Recent theoretical work proposes that prediction-error (PE) encoding is shaped by interneuron dynamics and plasticity, with neuromodulators playing a key role. Building on previous work in the Zwart lab demonstrating plasticity in the larval zebrafish PE centre, the inferior olive (IO), our hypothesis is that the neuromodulator norepinephrine encodes unexpectedness and temporarily boosts IO-driven synaptic plasticity so that the PE circuit adapts rapidly to surprising events while preserving long-term stability. Our modelling-first approach lets us generate quantitative, falsifiable plasticity rules that include neuromodulatory gating and identify the most informative experiments. Larval zebrafish provide an ideal test bed: their small, transparent brains can be imaged in their entirety, yet are complex enough to model vertebrate neural computations, and genetic tools enable targeted labelling and manipulations.

Project workflow

Modelling (months 1–21; Bonn)
The student will first build a multi-scale model to explain how the IO network adapts response amplitude according to stimulus surprise. We will identify biologically plausible circuits that reproduce our recorded changes in activity, incorporating error-driven spike-timing plasticity inspired by recent work (Hertäg et al 2025, Nejad et al 2025). We will use our model to (a) define the neuromodulatory signals acting upon synaptic plasticity that explain our experimental observations, (b) generate hypotheses for perturbation experiments, and (c) create a theory-experiment feedback loop to iteratively refine the model.

Experimental tests (months 22–42; St Andrews) + thesis writing, dissemination
Guided by modelling, the student will use our closed-loop VR behavioural setup and 2-photon IO activity imaging to:

1. Record neuromodulator dynamics alongside IO activity and behaviour using genetically encoded reporters during manipulations that cause prediction errors.
2. Perturb neuromodulatory systems using optogenetics or pharmacology during prediction errors to test effects on the formation and refinement of IO PE neurons. This will be combined with plasticity blockers to map sites and timescales of plasticity.

The work will be done jointly between the School of Psychology and Neuroscience at St Andrews and the Institute of Experimental Epileptology and Cognition Research at Bonn. The student will be supervised by Dr Maarten Zwart (St Andrews) and Prof. Tatjana Tchumatchenko (Bonn).

Informal enquiries regarding this scholarship may be addressed to the co-supervisors, using the email subject ‘Enquiry Global PhD Tchumatchenko Zwart’:

Dr Maarten Zwart (mfz@st-andrews.ac.uk) and Prof. Tatjana Tchumatchenko (tatjana.tchumatchenko@uni-bonn.de)

Value of award (per year)

The funding comprises a scholarship equivalent of a full-fees award and stipend for a period of up to 3.5 years. It is expected that the student will spend half of the scholarship term at the University of St Andrews and half at the University of Bonn:

• For the period spent at the University of St Andrews, the scholarships will comprise a full tuition fee award and an annual stipend paid at a rate set by the University of St Andrews. For 2025-2026, the stipend is £19,775 p.a., with an annual uplift published by the University each academic year.

• For the period spent at the University of Bonn, the scholarship will comprise a monthly maintenance grant of €1,800. The University of Bonn does not charge any tuition fees, but students must pay a so-called social contribution once per semester (currently €315 per semester).

Unless otherwise specified, the scholarships do not cover:

• Any continuation, extension, or resubmission period/fees.
• A research training grant or another equivalent award for research expenses.
• Support for travel, immigration, health insurance and related charges between the partner institutions.

Duration of award

Up to 3.5 years. The student will be expected to spend approximately half of the award term at the University of St Andrews and half at the University of Bonn. The successful candidate will be expected to have completed the doctorate degree by the end of the award term. The award term excludes the continuation period and any extension periods.

Additional criteria

Applicants must not already (i) hold a doctoral degree; or (ii) be matriculated for a doctoral degree at either the University of St Andrews or the University of Bonn (or another institution).

How to apply

Submit an application to Dr Maarten Zwart (mfz@st-andrews.ac.uk) and Prof. Tatjana Tchumatchenko (tatjana.tchumatchenko@uni-bonn.de), using the email subject ‘Application Global PhD Tchumatchenko Zwart’.  This should include the following documents:

• CV including information about publications.
• Transcripts of most relevant/recent degrees.
• Detailed information about research experience.
• Statement of suitability and motivation as a candidate for the project (max 300 words)

Following a successful application for the scholarship, candidates may be invited to submit an application to both universities for admission into the program and award of the scholarship.

Next steps

Successful scholarship applicants will be invited to apply for admission to both universities from April 2026, and then formal outcomes of the position will be made, subject to provision of full application details and materials for entry to the programme at the agreed entry point in 2026-2027.

Successful scholarship applicants must meet all relevant entry requirements for admission including any immigration requirements that may be in place. Please see the advice on applying for research degree programmes at St Andrews and the PhD application guidelines at Bonn.

Terms and conditions

Please read the University of St Andrews scholarships terms and conditions

These are applicable during the St Andrews duration of the award; please consult the partner institution for their terms and conditions relating to scholarships.

When will I know the outcome?

By mid-April 2026. Awards are subject to final signatures of contracts between the parties and successful admission to both institutions.