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Related Experiment Video

Updated: Apr 17, 2026

Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments

Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments

Published on: January 23, 2017

Spatial attention increases the pupillary response to light changes.

Paola Binda¹, Scott O Murray²

¹University of Washington, Department of Psychology, Seattle, WA, USA University of Pisa, Department of Translational Research on New Technologies in Medicine and Surgery, Pisa, Italy.

Journal of Vision

|February 4, 2015

Summary

This summary is machine-generated.

Pupil size changes are influenced by visual attention. Directing attention to a stimulus enhances pupillary responses, revealing attention

Keywords:

attention attentional enhancement pupillary light response

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Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity

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Published on: March 18, 2019

Area of Science:

Cognitive Neuroscience
Ophthalmology
Psychology

Background:

Pupil size changes (pupillary responses) are traditionally linked to light levels and arousal.
Ocular behaviors like pupillary responses were often considered simple, subcortical reflexes.
The role of higher cortical functions, such as attention, in modulating these responses was unclear.

Purpose of the Study:

To investigate whether spatial attention influences pupillary responses to visual stimuli.
To determine if pupillometry can serve as a measure of attentional effects on sensory processing.

Main Methods:

Adult human subjects maintained central fixation.
Visual scene luminance was manipulated.
Spatial attention was covertly directed to stimulus regions or opposite hemifields.
Pupil size was continuously measured.

Main Results:

Pupillary constrictions and dilations were significantly larger when attention was directed towards the stimulus region compared to the opposite hemifield.
This attentional enhancement effect was substantial, exceeding 20% of the response in the unattended hemifield.
The effect persisted regardless of the size or focus of the attended region.

Conclusions:

Pupillary responses are modulated by cortical attentional processes, not solely by subcortical reflexes.
Pupillometry offers an objective measure of attention and its impact on sensory processing.
This technique extends beyond assessing retinal and brainstem function to evaluating complex cognitive constructs.