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

Conference proceedings papers