Journal of Eye Movement Research

7 pages, 253 KiB

Open AccessArticle

Comparison of Shutter Glasses and Mirror Stereoscope for Measuring Dynamic and Static Vergence

by Wolfgang Jaschinski, Stephanie Jainta and Jörg Hoormann

J. Eye Mov. Res. 2007, 1(2), 1-7; https://doi.org/10.16910/jemr.1.2.5 - 1 Oct 2008

Cited by 3 | Viewed by 40

Vergence eye movement recordings in response to disparity step stimuli require to present different stimuli to the two eyes. The traditional method is a mirror stereoscope. Shutter glasses are more convenient, but have disadvantages as limited repetition rate, residual cross task, and reduced luminance. Therefore, we compared both techniques measuring (1) dynamic disparity step responses for stimuli of 1 and 3 deg and (2) fixation disparity, the static vergence error. Shutter glasses and mirror stereoscope gave very similar dynamic responses with correlations of about 0.95 for the objectively measured vergence velocity and for the response amplitude reached 400 ms after the step stimulus (measured objectively with eye movement recordings and subjectively with dichoptic nonius lines). Both techniques also provided similar amounts of fixation disparity, tested with dichoptic nonius lines. Full article

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17 pages, 869 KiB

Open AccessArticle

Audio-Visual Integration During Overt Visual Attention

by Cliodhna Quigley, Selim Onat, Sue Harding, Martin Cooke and Peter König

J. Eye Mov. Res. 2007, 1(2), 1-17; https://doi.org/10.16910/jemr.1.2.4 - 17 Sep 2008

Cited by 10 | Viewed by 52

Abstract

How do different sources of information arising from different modalities interact to control where we look? To answer this question with respect to real-world operational conditions we presented natural images and spatially localized sounds in (V)isual, Audiovisual (AV) and (A)uditory conditions and measured subjects' eye-movements. Our results demonstrate that eye-movements in AV conditions are spatially biased towards the part of the image corresponding to the sound source. Interestingly, this spatial bias is dependent on the probability of a given image region to be fixated (saliency) in the V condition. This indicates that fixation behaviour during the AV conditions is the result of an integration process. Regression analysis shows that this integration is best accounted for by a linear combination of unimodal saliencies. Full article

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7 pages, 349 KiB

Open AccessArticle

The Effect of Calibration Errors on the Accuracy of the Eye Movement Recordings

by Jörg Hoormann, Stephanie Jainta and Wolfgang Jaschinski

J. Eye Mov. Res. 2007, 1(2), 1-7; https://doi.org/10.16910/jemr.1.2.3 - 6 Aug 2008

Cited by 2 | Viewed by 36

Abstract

For calibrating eye movement recordings, a regression between spatially defined calibration points and corresponding measured raw data is performed. Based on this regression, a confidence interval (CI) of the actually measured eye position can be calculated in order to quantify the measurement error introduced by inaccurate calibration coefficients. For calculating this CI, a standard deviation (SD)-depending on the calibration quality and the design of the calibration procedure-is needed. Examples of binocular recordings with separate monocular calibrations illustrate that the SD is almost independent of the number and spatial separation between the calibration points–even though the later was expected from theoretical simulation. Our simulations and recordings demonstrate that the SD depends critically on residuals at certain calibration points, thus robust regressions are suggested. Full article

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12 pages, 733 KiB

Open AccessArticle

A Pragmatic Approach to Multi-Modality and Non-Normality in Fixation Duration Studies of Cognitive Processes

by Chie Nakatani and Cees van Leeuwen

J. Eye Mov. Res. 2007, 1(2), 1-12; https://doi.org/10.16910/jemr.1.2.2 - 9 Jul 2008

Cited by 6 | Viewed by 63

Abstract

Interpreting eye-fixation durations in terms of cognitive processing load is complicated by the multimodality of their distribution. An important source of multimodality is the distinction between single and multiple fixations to the same object. Based on the distinction, we separated a log-transformed distribution made to an object in non-reading task. We could reasonably conclude that the separated distributions belong to the same, general logistic distribution, which has a finite population mean and variance. This allowed us to use the sample means as dependent variables in a parametric analysis. Six tasks were compared, which required different levels of post-perceptual processing. A no-task control condition was added to test for perceptual processing. Fixation durations differentiated task-specific perceptual, but not post-perceptual processing demands. Full article

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11 pages, 414 KiB

Open AccessArticle

Saccadic Behavior During the Response to Pure Vergence Stimuli I: General Properties

by John L. Semmlow, Yung-Fu Chen, Tara Alvarez and Claude Pedrono

J. Eye Mov. Res. 2007, 1(2), 1-11; https://doi.org/10.16910/jemr.1.2.1 - 7 Nov 2007

Cited by 4 | Viewed by 61

Abstract

If two targets are carefully aligned so that they fall along the cyclopean axis, the required eye movement will be symmetrical with the two eyes turning equally inward or outward. When such “pure vergence stimuli” are used only a “pure vergence movement” is required, yet almost all responses include saccadic eye movements, a rapid tandem movement of the eyes. When saccades occur, they must either produce an error in the desired symmetrical response or correct an error from an asymmetrical vergence response. A series of eye movement responses to pure convergence step stimuli (4.0 deg step stimuli) were measured in 12 subjects and the occurrence, timing and amplitude of saccades was measured. Early saccades (within 400 msec of the stimulus onset) appeared in 80% to 100% of the responses. In most subjects, the first saccade increased the asymmetry of the response, taking the eyes away from the midline position. In three subjects, these asymmetry- inducing saccades brought one eye, the preferred or dominant eye, close to the target, but in the other subjects these asymmetry-inducing saccades were probably due to the distraction caused by the transient diplopic image generated by a pure vergence stimulus. While many of these asymmetry-inducing saccades showed saccade-like enhancements of vergence, they were, with the exception of two subjects, primarily divergent and did not facilitate the ongoing convergence movement. All subjects had some responses where the first saccade improved response symmetry, correcting an asymmetry brought about by unequal vergence movements in the two eyes. In five subjects, large symmetry-inducing saccades corrected an asymmetrical vergence response, bringing the eyes back to the midline (to within a few tenths of a degree). Full article

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J. Eye Mov. Res., Volume 1, Issue 2 (October 2007) – 5 articles

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