Porta Test of Eye Dominance

Technical Manual

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Credits:
https://gorilla.sc/openmaterials/104636

Created: December 29, 2020

Last Modified: May 22, 2026 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements an adaption of the Porta Test of Ocular Dominance (Porac & Coren, 1976) as used by the Behavioural Laterality Battery (Parker et al, 2020). The original pointing test is named after the Italian physician Giambattista della Porta who first described it in 1593.

References

Adam J. Parker , Zoe V. J. Woodhead , Paul A. Thompson & Dorothy V. M. Bishop (2020): Assessing the reliability of an online behavioural laterality battery: A pre-registered study, Laterality, DOI: 10.1080/1357650X.2020.1859526 https://doi.org/10.1080/1357650X.2020.1859526

Porac, C., & Coren, S. (1976). Psychological bulletin, 83, 880. https://doi.org/10.1037/0033-2909.83.5.880

Duration

1 minutes

Description

Participants are asked to determine their ocular dominance by using their thumb or index finger and centering them on a far away object. Then they are asked to close their left eye and then the right eye to observe the location of the object: the eye that keeps the object stationary is defined as the 'dominant' eye

Instructions

provided by Parker et al (2020)

Summary Data

File Name: blb_portatest_summary.iqdat

Data Fields

NameDescription
startDate Date the session was run
startTime Time the session was run
subjectId Participant ID
groupId Group number
sessionId Session number
elapsedTime Session duration in ms
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
computer.touch 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities
computer.hasKeyboard 0 = no external keyboard detected; 1 = external keyboard detected
completed 0 = Test was not completed
1 = Test was completed

Raw Data

File Name: blb_portatest.iqdat

Data Fields

NameDescription
date Date the session was run
time Time the session was run
subject Participant ID
group Group number
session Session number
build Inquisit version number
q*_response Response given (in assigned values)
Scale: RIGHT, LEFT, DON'T KNOW
q*_latency How much time (in ms) the participant spent on the surveyPage with this particular
question (the last time this particular surveyPage was visited)