Experimental Psychology Seminar - John Greenwood, UCL

Venue: Room 313, 26 Bedford Way.

A buffet lunch will be available just before the talk at 12.30pm in room 313BW.

You may also attend virtually via zoom: 
https://ucl.zoom.us/j/91768876812?pwd=aExJVmFTZnBZZCtFbmlGS0tSY2VCdz09
Meeting ID: 917 6887 6812
Passcode: 950231

Title:
Using typical vision to understand clinical disorders of vision

Abstract:
Our ability to recognise objects in the world is impaired in cluttered environments, even for objects that are clearly visible in isolation. This process, known as crowding, presents the fundamental limit on our peripheral vision. These disruptive effects are elevated in foveal vision (the centre of our gaze) during development, and further elevated in clinical disorders including amblyopia (‘lazy eye’) and nystagmus (uncontrolled eye movements), placing a limit on everyday tasks like reading.

Can we understand the mechanisms underlying these elevations using crowding in the typical periphery? I will first show that crowding produces the same kinds of errors in peripheral vision as in the foveal vision of typical and amblyopic children. These errors are well described in all cases by ‘pooling’ models that depict crowding as an unwanted combination of cluttered elements. In peripheral vision, crowding can also independently disrupt judgements of colour and motion for the same target object, suggesting the existence of multiple instances of crowding throughout the visual system. Dissociations between the crowding of colour and motion are similarly evident in amblyopic vision. Together, our findings depict crowding as a process that simplifies the visual scene to provide a ‘gist’ that can be efficiently encoded with reduced neural resources.