Small eye movements cannot be reliably measured by video-based P-CR eye-trackers
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14210%2F20%3A00124622" target="_blank" >RIV/00216224:14210/20:00124622 - isvavai.cz</a>
Result on the web
<a href="https://link.springer.com/article/10.3758/s13428-020-01363-x#Ack1" target="_blank" >https://link.springer.com/article/10.3758/s13428-020-01363-x#Ack1</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3758/s13428-020-01363-x" target="_blank" >10.3758/s13428-020-01363-x</a>
Alternative languages
Result language
angličtina
Original language name
Small eye movements cannot be reliably measured by video-based P-CR eye-trackers
Original language description
For evaluating whether an eye-tracker is suitable for measuring microsaccades, Poletti & Rucci (2016) propose that a measure called ‘resolution’ could be better than the more established root-mean-square of the sample-to-sample distances (RMS-S2S). Many open questions exist around the resolution measure, however. Resolution needs to be calculated using data from an artificial eye that can be turned in very small steps. Furthermore, resolution has an unclear and uninvestigated relationship to the RMS-S2S and STD (standard deviation) measures of precision (Holmqvist & Andersson, 2017, p. 159-190), and there is another metric by the same name (Clarke, Ditterich, Drüen, Schönfeld, and Steineke 2002), which instead quantifies the errors of amplitude measurements. In this paper, we present a mechanism, the Stepperbox, for rotating artificial eyes in arbitrary angles from 1′ (arcmin) and upward. We then use the Stepperbox to find the minimum reliably detectable rotations in 11 video-based eye-trackers (VOGs) and the Dual Purkinje Imaging (DPI) tracker. We find that resolution correlates significantly with RMS-S2S and, to a lesser extent, with STD. In addition, we find that although most eye-trackers can detect some small rotations of an artificial eye, the rotations of amplitudes up to 2∘ are frequently erroneously measured by video-based eye-trackers. We show evidence that the corneal reflection (CR) feature of these eye-trackers is a major cause of erroneous measurements of small rotations of artificial eyes. Our data strengthen the existing body of evidence that video-based eye-trackers produce errors that may require that we reconsider some results from research on reading, microsaccades, and vergence, where the amplitude of small eye movements have been measured with past or current video-based eye-trackers. In contrast, the DPI reports correct rotation amplitudes down to 1′.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
50103 - Cognitive sciences
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Behavior Research Methods
ISSN
1554-351X
e-ISSN
1554-3528
Volume of the periodical
52
Issue of the periodical within the volume
5
Country of publishing house
US - UNITED STATES
Number of pages
24
Pages from-to
2098-2121
UT code for WoS article
000521705600001
EID of the result in the Scopus database
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