Professor John Porrill BA, PhD

The University of Sheffield
Sheffield S10 2TP, UK
Tel: (+44) 0114 222 6557
Fax: (+44) 0114 276 6515
Room: G-15


BA, PhD (Cantab)

Research Interests

My research is aimed at developing a computational understanding of the brain and its role in behaviour.

Mathematical modelling
Very fruitful collaborations with psychologists and neuroscientists (my own training is as a mathematician and theoretical physicist) have allowed me to develop a programme of research based on combining rigorous mathematical modelling with a detailed understanding of the underlying neuroscience.

Identifying the cerebellar algorithm
The central theme of my current research is to identify the cerebellar algorithm. With colleagues I have developed a view of cerebellar function which emphasises the importance of a basic 'decorrelation control' algorithm implemented in the repeating microcircuit based around the Purkinje cell.

This research has been more successful than we could have hoped. For example:

  • It provides a unified description of sensory and motor functions;
  • It has revealed a surprising functional role for closed cerebellar loops which have recently been traced in detail and whose function is regarded as a challenge to theorists;
  • It has provided a computational answer to the longstanding puzzle as to why there are two sites of plasticity in VOR adaptation;
  • In addition the algorithm has been implemented in hardware by our collaborators in Bristol Robotics Lab and is successfully learning to stabilise a robot mounted camera.

Our enthusiasm for a cross-disciplinary approach makes myself and my close colleague Paul Dean natural partners in current and planned multi-site research programmes linking neuroscience and robotics.


BBSRC, Dean & Porrill Sheffield, lead by UCL with Cambridge: Cerebellum as a neuronal machine: behavioural, electrophysiological and computational analysis of classical conditioning. (2004 for 3yrs) c. £750K

EPSRC, lead by Dean & Porrill, Sheffield with Edinburgh & UWE: Functions of Distributed Plasticity in a Biologically-Inspired Adaptive Control Algorithm: From Electrophysiology to Robotics. (2004for 3yrs) £767K.

BBSRC, Dean & Porrill: Neural Control of Eye Movements (2000 for 3yrs) £120,000

Teaching and administrative duties

I am module organiser for module 336. I am also responsible for U/g admissions and sit on the Psychology Management Committee, Psychology Teaching Committee, Computing Committee and Postgraduate Studies Committee.

Activities and Distinctions

  • I was an invited participant in recent workshops on the future of cerebellar research held at the University of Tuebingen & St Louis and co-author of the workshop review in Cerebellum.
  • I was an invited participant in the Foresight Cognitive Systems Project InterAction conference organised in 2003 by the DTI and in a number of Cluster Group Meetings supported by the EPSRC in 2004.
  • I was elected Fellow of the Institute of Mathematics and its Applications in 2001.

Invited presentations include

  • London 2006: invited discussant Gatsby Foundation International conference on the Cerebellum
  • Edinburgh 2005, 2006: Neurosciences Graduate Program
  • Antwerp 2005: Neuro-IT Cerebellar Modeling Workshop
  • Dorchester 2005: Quinetiq Symposium: Learning in Neuronal Networks
  • Warwick 2005: Mathematical Neuroscience: network analysis
  • Tuebingen 2004: International Conference on the Cerebellum
  • Oxford 2004: Symposium on Biological and Computational Vision
  • Edinburgh 2003: EPSRC Novel Computation Initiative

Postgraduate Students

  • I am currently co-supervising Adrian Haith, a PhD student at the University of Edinburgh in the Neuroinformatics Doctoral Training Centre.

Research Assistants

  • Dr Nathan Lepora (BBSRC)
  • Dr Sean Anderson (EPSRC)


A list of key publications can be found below.  For a full list of publications please click here

Journal articles


  • Wilson E, Anderson SR, Assaf T, Assaf T, Pearson MJ, Pearson MJ, Walters P, Walters P, Prescott TJ, Melhuish C, Melhuish C, Rossiter J, Rossiter J, Pipe T, Pipe T, Dean P & Porrill J (2012) Bioinspired control of electro-active polymers for next generation soft robots. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Vol. 7429 LNAI (pp 424-425)