Speaker:
Ph.D. Chin-An Wang
Research Center of Brain and Consciousness
Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University
Topic:
Neural Control of Pupil Responses
Venue:
Science Building #4, S4-209, NCU (中央大學科四館209室)
Date & Time:
2019/02/26, 14:00~16:00
(There will be post-seminar meeting after the talk.)
Neural Control of Pupil Responses
Pupil size, as a component of orienting, changes rapidly in response to local salient events in the environment in addition to global luminance modulation. Our recent research has shown that visual, auditory, or audiovisual stimuli can elicit transient pupil dilation, and the timing and magnitude of the evoked responses are systematically modulated by the salience of the stimuli. Moreover, microstimulation of the superior colliculus (SC), a midbrain structure causally involved in eye movements and attention, evokes similar transient pupil dilation, suggesting that the SC coordinates the orienting response which includes transient pupil dilation. Pupil size is also modulated by cognitive processes such as executive functioning. This function has been examined using the anti-saccade task where subjects are instructed to either look at the peripheral stimulus (pro-saccade) or to suppress the automatic pro-saccade response and voluntarily look in the opposite direction of the stimulus (anti-saccade). We have demonstrated that pupil size prior to stimulus appearance effectively predicts subsequent saccadic behaviors, arguably through the projections from the SC to the pupil control circuitry. Furthermore, this profile of pupil size modulation is significantly blunted in ageing and patient populations, reflecting debilitated circuits for voluntary saccade preparation. Pupillometry is an easy-to-measure way to understand neural and cognitive processing. Our results not only demonstrate the sensory and cognitive modulation on pupil size, but also provide the neural substrate underlying this modulation.