Professor Petroc Sumner
Professor and Head of School, School of Psychology
Perception and action
How do visual signals, even ones that we do not consciously perceive, trigger actions? How do we control our behaviour so that we do not reflexively respond when we don’t want to? Why do people differ from each other in these basic mechanisms?
Control of basic behaviour can be disrupted by brain damage or degeneration or in mental disorders, and lapses occur often in all of us. Our research aims to help us understand the exact reasons why.
We use a range of methods with both healthy volunteers and patients, integrating precise behavioural measures (including eye tracking) with imaging (fMRI and MEG) and spectroscopy.
A non-specialist review relating to our work can be found in: Sumner, P. and Husain, M (2008). At the edge of consciousness: automatic motor activation and voluntary control. The Neuroscientist, 14, 474-486. [pdf]. We also occasionally write articles in the press (e.g. Riot control; Science reporting)
Science in the media
Recently we have also launched a project investigating where things go wrong in the communication between scientists and journalists, with a view to trying to improve the way health-related research is reported in the press. See insciout.com for more information.
Levels 1 and 2: I teach introductory lectures on perception, biological psychology and testing evolutionary theories (PS1016 and PS1014), run perception practicals (PS2009), and give tutorials on research, perception, cognition and abnormal psychology (supporting PS1014, PS2003, PS2008, PS2009).
Level 3: In 2011/12 Tom Freeman, Simon Rushton and I offer a 20-credit module in vision and action, which integrates various topics concerning how actions affect perception and how visual information is used to guide both unconscious and conscious action plans. I supervise projects on action control and perception.
I am also coordinator for the Bioscience students taking psychology modules as part of their Neuroscience pathway.
- 1996: BA in Natural Sciences, 1st Class, University of Cambridge. Foundation Scholarship, Caldwell Scholarship and Bishop Green Cup.
- 2000: PhD, Dept Experimental Psychology, University of Cambridge. Supervised by J.D. Mollon.
- 2003: Diploma of Imperial College, London, in Advanced Study in Learning and Teaching.
Honours and awards
- David Marr Medal, Applied Vision Association.
- 2003: Experimental Psychology Society
- 2004: Higher Education Academy
- 2005: Applied Vision Association
- 2007: American Physiological Society
- 2009: ESRC peer review college
- 2000-2006: Lecturer, Division of Neuroscience and Psychological medicine, Imperial College London.
- 2006-present: Lecturer/Senior Lecturer/Reader, School of Psychology, Cardiff University
Grant reviewing: BBSRC; ESRC; MRC; Wellcome Trust; Australian Research Council; National Science Foundation (USA); NWO (The Netherlands).
Consulting Editor for JEP, HPP.
Journal reviewing (23 different journals, including Science, PNAS, Current Biology, Neuron, J. neuroscience).
Invited talks and symposia (e.g. University of Western Australia, Perth; University of Queensland, Brisbane; University of Geneva; Rank Prize Fund, Kingston (Canada), John Hopkins (Baltimore), AVA, BOMG, HBM, ICON, ECEM)
PhD examining (internal and external).
Research topics and related papers
See it, grab it: Control of automatic sensorimotor behaviour in health and disease (funded by Wellcome Trust, and joint with UCL).
How does the brain control the links between perception and action, and what happens when such control is disrupted by brain damage? Traditionally, the control of action has been separated into automatic and volitional processes. Our hypothesis is that these two activities are in fact inextricably related. Visual objects automatically activate (prime) motor plans which facilitate actions towards these objects. But if our actions are not always to be driven by environmental stimuli, such priming must be inhibited to allow alternative goals. We want to understand how automatic control processes are involved in such flexible, 'volitional’ control of behaviour, and why individuals differ in their ability to control basic behaviour. We employ behavioural tasks in healthy and brain-damaged people, and use the imaging facilities in CUBRIC.
How are eye movement decisions made? (application to ESRC)
To explain decisions without recourse to a separate intelligent agent (the homunculus problem), we must assume they arise from some combination of sensory input (evidence), the dynamic state the brain is in when those inputs arrive (including memory, goal states etc), and some random noise. All models of decision making envisage an integration of these ingredients into accumulating activity in favour of one choice or another. As soon as the accumulation for one choice reaches a threshold, the decision is made. We use the umbrella term “first-to-threshold” to refer to this way of conceptualising decisions.
Thus the probability of a simple action being chosen should depend on how quickly the accumulation process for that action tends to reach threshold. This is also a key component in the time it takes to initiate the action. Choice should therefore be inextricably linked to response times. However, the first-to-threshold idea is so widespread and so intuitive that this fundamental prediction has been overlooked, despite it having the power to overturn all current models, indeed our entire conceptualisation of how a brain can make decisions. Yet our preliminary data suggest that the prediction is incorrect.
Why don’t we see what our eyes are telling us? (funded by ESRC)
Our eyes and visual system introduce various distortions and imperfections into the visual image, but our everyday perception appears immune to them. How is this achieved? We are investigating two aspects of this issue: 1) how does macular pigment in the retina influence colour perception? 2) why do we not see colour after-effects all the time, even though they are quick and easy to elicit in demonstrations (and why do they go away or come back when we blink?)
Automatic influences on eye movement planning and attentional shifts
Variousrelated experiments are ongoing in this category, including: 1) investigations of saccade distractor effects and their relationship to GABA (an inhibitory neurotransmitter);2) subliminal attentional triggers and the retinotectal pathway 3) how saccade curvature is related to response inhibition; 4) how saccade plans cope with nystagmus (do the voluntary systems know what the subcortical automatic systems are doing?)
- ESRC (2013-2016, £633,613) A framework and toolkit for understanding impulsive action. Petroc Sumner, Aline Bompas, Chris Chambers, Casimir Ludwig, Frederick Verbruggen, Fred Boy.
ESRC (2103-2016) Grant-linked studentship: The role of flexibility in impulsivity. Petroc Sumner, Chris Chambers.
- ESRC (2103-2016) Grant-linked studentship: The role of flexibility in impulsivity. Petroc Sumner, Chris Chambers.
- BIAL foundation (39K Euro) The Neurochemistry of Gambling-Related Impulsive Cognition and Decision-Making: a Multimodal Imaging Approach. PI Fred Boy.
- Alcohol Research UK (ARUK) studentship award (2012-2015) 'Individual differences in the effect of alcohol on cognitive control.’
- British Psycology Society (2012) 'Are press releases to blame in the miscommunication of science?’ £3,400.
- Wellcome Trust Value in People award (supervisor/sponsor of Fred Boy). £40500 (2011-2012).
- Wellcome Trust project grant (2009-2012, £426 191): See it, grab it: Control of automatic sensorimotor behaviour in health and disease. Petroc Sumner, Masud Husain, Krish Singh, Bob Rafal. Research Associates: Fred Boy (Cardiff) and Jen McBride (UCL)
- ESRC project Grant (2009-2010, £82 039) Is perceived colour altered when we move our eyes. Petroc Sumner and Aline Bompas.
- BBSRC Project Grant, (2005-2008, £194 578):Using S cones to investigate the role of the superior colliculus in automatic visual processes. Petroc Sumner and Masud Husain. Research Associates: Elaine Anderson and Aline Bompas
- WICN pilot grants (2007-2009, £33K) Control of automaticity and automaticity of control; Influence of frontal eye fields on contrast perception; GABA and saccade inhibition.
- We have also been supported by Nuffield and Wellcome summer scholarships, and by Royal Society travel and small project grants.
- Krish Singh (all imaging aspects of our projects).
- Chris Chambers and team (attention project and TMS).
- Suresh Muthukumaraswamy (MEG experiments)
- John Evans (fMRI and MR spectroscopy)
- Tom Freeman (nystagmus, smooth pursuit and saccades)
- Simon Rushton (visual anomalies in Huntingdon’s Disease, fMRI of objects in motion)
- Bill Macken and Dylan Jones (motor activation by auditory sequences)
- Ursula Budnik, Chris Allen, Georgina Powell, Sian Griffiths, David Maidment.James Harrison (PhD students; see Postgraduate page).
- Aline Bompas
- Fred Boy
- Masud Husain and Jen Mcbride (Institute of Neurology and Institute of Cognitive Neuroscience, UCL, London; 'See it, grab it’ project)
- Bob Rafal (Bangor; patient studies)
- Richard Edden (John Hopkins, Baltimore; MR spectroscopy)
- Robin Walker and Frouke Hermens (Royal Holloway; saccade curvature and inhibition)
- Iain Gilchrist (Bristol; variability of saccade latency)
- Elaine Anderson (Optometrist and UCL; previously Post-doc on BBSRC grant)
- Parashkev Nachev (Institute of Neurology; control, inhibition and conflict)
- Monica Busse-Morris (Physiotherapy, Cardiff; visual anomalies in Huntingdon’s Disease)
- Replication is the only solution to scientific fraud - Guardian
- Science journalism through the looking glass - Guardian
- Nine ways scientists can help improve science journalism - Guardian
- How can we ensure a future of quality science reporting in the UK? - submission to the Leveson Inquiry
- Cerveau et maintien de l’ordre, comment améliorer l’information scientifique du grand public? - En Quete de Sciences
- Scientists should be allowed to check stories on their work before publication - Guardian
- Riot control: How can we stop newspapers distorting science? - Guardian