CiNet Monthly Seminar

February 21, 2024
16:00-17:00 (JST)
at CiNet Conference Room in the CiNet bldg.

“Inferring perceptual states from fixational eye movements”

Neil W. Roach
Professor of Vision Science
School of Psychology
University of Nottingham, UK

Host :  Masamichi Hayashi, Natsuki Ueda

Abstract:
Even when we attempt to maintain steady fixation on an object, our eyes drift and we make small ballistic movements called microsaccades. Although we are seldom aware of these fixational eye movements, it is becoming increasingly clear that they can provide a window onto perceptual and cognitive processes occurring within the brain. In this talk I will describe two lines of research exploiting information contained in the timing of microsaccades to make inferences about individuals’ perceptual states. First, I will show that inhibition of microsaccades after the onset of transient visual stimuli is highly sensitive to stimulus visibility, providing the basis for an automated, objective method of measuring visual contrast sensitivity during passive viewing. Second, I will demonstrate that microsaccade rate can also be used to infer individuals’ expectations regarding the timing of future stimuli. Interestingly, these ‘oculomotor expectations’ can be dissociated from expectations inferred from Bayesian time perception paradigms, raising the possibility that multiple domain-specific forms of temporal expectation coexist in the human brain.