UCL Division of Biosciences


John Greenwood

Experimental Psychology, UCL

(i) a 1/3 line description of your field of research (about 35 characters) to go into the part of the PhD timetable giving an overview of the supervisors available;

Visual perception & psychophysics

(ii) a description of your research with possible PhD projects available and 3 references to published papers, about half a page altogether, to go on the website: please look at the website and copy the format of the existing entries.

What is it that allows us to see the world as we do? Our research aims to understand the mechanisms underlying our visual perception, and how this is disrupted in clinical conditions like amblyopia ('lazy eye') and congenital nystagmus (uncontrolled eye movements), amongst others. One of our main areas of research is 'visual crowding' - the disruptive effect of clutter on object recognition. Crowding is a fundamental limitation on peripheral vision and becomes especially problematic in a range of visual disorders. We are also interested in the perception of motion, position, and faces. Our research techniques include behavioural psychophysics, functional magnetic resonance imaging (fMRI), eye tracking and computational modelling. See our website at http://eccentricvision.com for more.

Available projects

Projects could be designed around any aspect of visual perception - here are a few ideas based on our current interests:

1. Visual crowding in dyslexia: Crowding may be elevated in the foveal/central vision of people with dyslexia. This has been reported in letter recognition tasks, but not with simpler elements (e.g. line orientation). We aim to examine whether dyslexic crowding is a general visual phenomenon or a specific deficit for cluttered letters.

2. Variations in face perception across the visual field: Face recognition varies dramatically across the visual field - the same face can appear to be male in one part of the visual field and female in another. We hope to examine the basis of these variations and their potential neural correlates.

Selected publications

Kalpadakis-Smith, A. V., Goffaux, V., & Greenwood, J. A. (2017). Crowding is not holistic: Visual similarity determines the effect of clutter on faces. PsyArXiv, http://osf.io/preprints/psyarxiv/2z8un

Greenwood, J. A., Szinte, M., Sayim, B., & Cavanagh, P. (2017). Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision. Proceedings of the National Academy of Sciences, 114(17), E3573-E3582.

Anderson, E. J., Dakin, S. C., Schwarzkopf, D. S., Rees, G., & Greenwood, J. A. (2012). The neural correlates of crowding-induced changes in appearance. Current Biology, 22(13), 1199-1206.