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The influence of crystalline lens accommodation on post-saccadic oscillations in pupil-based eye trackers

Nyström, Marcus LU ; Andersson, Richard LU ; Magnusson, Måns LU ; Pansell, Tony and Hooge, Ignace (2015) In Vision Research 107. p.1-14
Abstract
It is well known that the crystalline lens (henceforth lens) can oscillate (or 'wobble') relative to the eyeball at the end of saccades. Recent research has proposed that such wobbling of the lens is a source of post-saccadic oscillations (PSOs) seen in data recorded by eye trackers that estimate gaze direction from the location of the pupil. Since the size of the lens wobbles increases with accommodative effort, one would predict a similar increase of PSO-amplitude in data recorded with a pupil based eye tracker. In four experiments, we investigated the role of lens accommodation on PSOs in a video-based eye tracker. In Experiment 1, we replicated previous results showing that PSO-amplitudes increase at near viewing distances (large... (More)
It is well known that the crystalline lens (henceforth lens) can oscillate (or 'wobble') relative to the eyeball at the end of saccades. Recent research has proposed that such wobbling of the lens is a source of post-saccadic oscillations (PSOs) seen in data recorded by eye trackers that estimate gaze direction from the location of the pupil. Since the size of the lens wobbles increases with accommodative effort, one would predict a similar increase of PSO-amplitude in data recorded with a pupil based eye tracker. In four experiments, we investigated the role of lens accommodation on PSOs in a video-based eye tracker. In Experiment 1, we replicated previous results showing that PSO-amplitudes increase at near viewing distances (large vergence angles), when the lens is highly accommodated. In Experiment 2a, we manipulated the accommodative state of the lens pharmacologically using eye drops at a fixed viewing distance and found, in contrast to Experiment 1, no significant difference in PSO-amplitude related to the accommodative state of the lens. Finally, in Experiment 2b, the effect of vergence angle was investigated by comparing PSO-amplitudes at near and far while maintaining a fixed lens accommodation. Despite the pharmacologically fixed degree of accommodation, PSO-amplitudes were systematically larger in the near condition. In summary, PSOs cannot exhaustively be explained by lens wobbles. Possible confounds related to pupil size and eye-camera angle are investigated in Experiments 3 and 4, and alternative mechanisms behind PSOs are probed in the discussion. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Vision Research
volume
107
pages
1 - 14
publisher
Elsevier
external identifiers
  • pmid:25481633
  • wos:000348632600001
  • scopus:84918820960
ISSN
1878-5646
DOI
10.1016/j.visres.2014.10.037
language
English
LU publication?
yes
id
ee71e516-bbfe-4f34-9c3b-983cee83c2cd (old id 4909556)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/25481633?dopt=Abstract
date added to LUP
2015-01-10 13:04:38
date last changed
2017-09-03 03:13:17
@article{ee71e516-bbfe-4f34-9c3b-983cee83c2cd,
  abstract     = {It is well known that the crystalline lens (henceforth lens) can oscillate (or 'wobble') relative to the eyeball at the end of saccades. Recent research has proposed that such wobbling of the lens is a source of post-saccadic oscillations (PSOs) seen in data recorded by eye trackers that estimate gaze direction from the location of the pupil. Since the size of the lens wobbles increases with accommodative effort, one would predict a similar increase of PSO-amplitude in data recorded with a pupil based eye tracker. In four experiments, we investigated the role of lens accommodation on PSOs in a video-based eye tracker. In Experiment 1, we replicated previous results showing that PSO-amplitudes increase at near viewing distances (large vergence angles), when the lens is highly accommodated. In Experiment 2a, we manipulated the accommodative state of the lens pharmacologically using eye drops at a fixed viewing distance and found, in contrast to Experiment 1, no significant difference in PSO-amplitude related to the accommodative state of the lens. Finally, in Experiment 2b, the effect of vergence angle was investigated by comparing PSO-amplitudes at near and far while maintaining a fixed lens accommodation. Despite the pharmacologically fixed degree of accommodation, PSO-amplitudes were systematically larger in the near condition. In summary, PSOs cannot exhaustively be explained by lens wobbles. Possible confounds related to pupil size and eye-camera angle are investigated in Experiments 3 and 4, and alternative mechanisms behind PSOs are probed in the discussion.},
  author       = {Nyström, Marcus and Andersson, Richard and Magnusson, Måns and Pansell, Tony and Hooge, Ignace},
  issn         = {1878-5646},
  language     = {eng},
  pages        = {1--14},
  publisher    = {Elsevier},
  series       = {Vision Research},
  title        = {The influence of crystalline lens accommodation on post-saccadic oscillations in pupil-based eye trackers},
  url          = {http://dx.doi.org/10.1016/j.visres.2014.10.037},
  volume       = {107},
  year         = {2015},
}