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Related Experiment Video

Updated: May 4, 2026

Development of a Gaze-Contingent Display Framework Designed for Perceptual and Oculomotor Research with Simulated Central Vision Loss

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Transient pupil response is modulated by contrast-based saliency.

Chin-An Wang¹, Susan E Boehnke, Laurent Itti

¹Centre for Neuroscience Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada, and Department of Computer Science, University of Southern California, Los Angeles, California 90089-0781.

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience

|January 10, 2014

Summary

This summary is machine-generated.

Novel stimuli trigger orienting responses, including pupil size changes. This study shows stimulus saliency influences pupil dilation speed and magnitude, suggesting superior colliculus involvement in this orienting reflex.

Keywords:

microstimulation orienting pupil response saliency stimulus contrast superior colliculus

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Area of Science:

Neuroscience
Cognitive Science
Ophthalmology

Background:

Orienting responses involve shifts in attention and gaze.
Stimulus saliency significantly impacts gaze shifts, but its effect on pupil size is less understood.

Purpose of the Study:

To investigate how stimulus saliency affects pupil size changes during orienting responses.
To explore the neural mechanisms underlying salience-evoked pupil responses.

Main Methods:

Monkeys fixated a central visual spot while presented with visual, auditory, or audiovisual stimuli.
Pupil size changes were recorded and analyzed in response to stimuli of varying saliency.
Stimulus-evoked pupil responses were compared to responses from midbrain superior colliculus microstimulation.

Main Results:

Transient pupil dilation occurred after visual and auditory stimulus presentation.
Pupil responses were modulated by contrast-based saliency, with more salient stimuli eliciting faster and larger dilations.
Audiovisual stimuli responses were predicted by linear summation of individual modality responses.
The initial pupil dilation component resembled responses from superior colliculus microstimulation.

Conclusions:

Transient pupil responses, part of the orienting reflex, are modulated by stimulus saliency.
The superior colliculus likely plays a role in coordinating these salience-driven pupil responses.