Pupillometry as an integrated readout of distinct attentional networks

The course of pupillary constriction and dilation provides an easy-to-access, inexpensive, and noninvasive readout of brain activity. We propose a new taxon-omy of factors affecting the pupil and link these to associated neural underpin-nings in an ascending hierarchy. In addition to two well-established low-level factors (light level and focal distance), we suggest two further intermediate -level factors, alerting and orienting, and a higher-level factor, executive function-ing. Alerting, orienting, and executive functioning - including their respective un-derlying neural circuitries - overlap with the three principal attentional networks, making pupil size an integrated readout of distinct states of attention. As a now widespread technique, pupillometry is ready to provide meaningful applications and constitutes a viable part of the psychophysiological toolbox.

Automated summary

The process of pupillary constriction and dilation can provide an accessible, affordable, and non-invasive measure of brain activity. A new taxonomy is proposed to understand the factors affecting pupil size and their neural underpinnings. Pupil size serves as an integrated measure of different attentional states.