Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2019 Jan 22;9:1190. doi: 10.3389/fneur.2018.01190

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2019 Ebitz and Moore.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

The PLR is correlated with stimulus attention and PLR magnitude can be used to probe the dynamics of visuospatial attention. (A) The PLR distraction task. In this task, PLR-evoking probes are presented in one of three locations relative to a rewarded target: above fixation, away from all possible target locations (“neutral”), on the same side as the rewarded target (“congruent”), or in the opposite hemifield from the rewarded target (“incongruent”). PLR probes were presented both before and at various latencies after target onset. (B) Some example pupil traces [data from Ebitz and Moore (28)] showing the characteristic light-evoked constriction after an evoking probe (purple) compared to sham-probe trials (gray). (C) Left: Response time effects of PLR probes in each location. Congruent probes sped response times, while incongruent ones slowed response time. Neutral probes had little impact on response time. Right: The evoked PLR strongly predicted the extent to which that probe would capture attention, as measured by response time effects of the probes. (D) PLR magnitude (bigger = more constriction) as a function of the timing of the PLR probe. If the probe was presented before the rewarded target (negative stimulus onset asynchrony), there was no difference between congruent and incongruent probes. All PLRs were suppressed to probes presented immediately after the rewarded target. Then, as monkeys began to prepare a saccade to the rewarded target, congruent probes PLRs (blue) were enhanced relative to both incongruent (red) and neutral (gray). Figures modified from Ebitz et al. (14) and Ebitz (29) under a Creative Commons Attribution license and with permission from copyright holders.