cff-version: 1.2.0
abstract: "Much psychological research uses pupil diameter measurements for
investigating the cognitive and emotional effects of visual stimuli. A
potential problem is that accommodating at a nearby point constricts the pupil.
This study examined to what extent accommodation is a confounder in
pupillometry research. Participants solved multiplication problems at different
distances (Experiment 1) and looked at line drawings with different monocular
depth cues (Experiment 2) while their pupil diameter, refraction, and vergence
angle were recorded using a photorefractor. Experiment 1 showed that the pupils
dilated while performing the multiplications, for all presentation distances.
Pupillary constriction due to accommodation was not strong enough to override
pupil dilation due to cognitive load. Experiment 2 showed that monocular depth
cues caused a small shift in refraction in the expected direction. We conclude
that, for the young student sample we used, pupil diameter measurements are not
substantially affected by accommodation."
authors:
  - family-names: Kooijman
    given-names: L. (Lars)
    orcid: "https://orcid.org/0000-0002-0902-5752"
  - family-names: Dodou
    given-names: Dimitra
    orcid: "https://orcid.org/0000-0002-9428-3261"
  - family-names: Jansen
    given-names: Stefan
  - family-names: Themans
    given-names: Tamir
  - family-names: Russell
    given-names: Julia
  - family-names: Petermeijer
    given-names: S.M. (Sebastiaan)
  - family-names: Doorman
    given-names: Just
  - family-names: Hablé
    given-names: Joelle
  - family-names: Neubert
    given-names: Dominik
  - family-names: Vos
    given-names: Margot
title: "Supplementary data for the paper 'Is accommodation a confounder in pupillometry research?'"
keywords:
version: 1
identifiers:
  - type: doi
    value: 10.4121/13721038.v1
license: CC0
date-released: 2021-02-12