Event

Does pupil size affect how we perceive the world?

  • Tue 27 Feb 18

    16:00 - 17:00

  • Colchester Campus

    1.702 - Department of Psychology

  • Event speaker

    Sabastiaan Mathot

  • Event type

    Lectures, talks and seminars

  • Event organiser

    Psychology, Department of

Pupils respond to three distinct kinds of stimuli: they constrict in response to brightness (the pupil light response), constrict in response to near fixation (the pupil near response), and dilate in response to increases in arousal and mental effort. But what are the functions of pupil responses--if all pupil responses even have a function? In this talk, I will discuss a series of recent studies in which we address the effect of pupil size on visual perception; crucially, in order to establish causal links, we experimentally manipulate pupil size in various ways.

Results so far suggest that large pupils facilitate detection of stimuli in peripheral vision, and may lead to an underestimation of stimulus brightness. Conversely, small pupils facilitate discrimination of fine stimuli in central vision, and may lead to an overestimation of stimulus brightness. More generally, I will argue that pupils change their size to optimize vision for particular situations.