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. 2013 Mar;45(1):289-300.
doi: 10.3758/s13428-012-0248-3.

Dynamic Visuomotor Synchronization: Quantification of Predictive Timing

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Free PMC article

Dynamic Visuomotor Synchronization: Quantification of Predictive Timing

Jun Maruta et al. Behav Res Methods. .
Free PMC article

Abstract

When a moving target is tracked visually, spatial and temporal predictions are used to circumvent the neural delay required for the visuomotor processing. In particular, the internally generated predictions must be synchronized with the external stimulus during continuous tracking. We examined the utility of a circular visual-tracking paradigm for assessment of predictive timing, using normal human subjects. Disruptions of gaze-target synchronization were associated with anticipatory saccades that caused the gaze to be temporarily ahead of the target along the circular trajectory. These anticipatory saccades indicated preserved spatial prediction but suggested impaired predictive timing. We quantified gaze-target synchronization with several indices, whose distributions across subjects were such that instances of extremely poor performance were identifiable outside the margin of error determined by test-retest measures. Because predictive timing is an important element of attention functioning, the visual-tracking paradigm and dynamic synchronization indices described here may be useful for attention assessment.

Figures

Fig. 1
Fig. 1
Typical visual-tracking performance during which a target moved in a circular trajectory of 10° radius at 0.4 Hz (Subject 046). a Two-dimensional trajectory of the gaze. b Scattergram of gaze positions relative to the target fixed at the 12 o’clock position. The center of the white circle indicates the average gaze position. The dot-dashed curve indicates the circular path. A proportionally sized target is drawn at the bottom. c Horizontal eye position (°). d Vertical eye position (°). e Horizontal eye velocity (°/s). f Vertical eye velocity (°/s). g Phase error relative to the target (°). A positive phase indicates lead
Fig. 2
Fig. 2
Relationship between horizontal and vertical tracking. Left: Gains. Right: RMS errors
Fig. 3
Fig. 3
Different grades of visual-tracking performance. ad Increases in positional error variability. The scattergrams follow the same convention as that in Fig. 1b. Each dot corresponds to a sample taken at 500 Hz; consequently, saccade trajectories are represented by series of discrete dots. MP, mean phase error (expressed in phase angle); SDTE, SD of tangential errors (expressed in visual angle)
Fig. 4
Fig. 4
Test–retest correlograms of raw and normalized data. aSD of tangential errors. b Mean phase error. c, d Horizontal and vertical gains of smooth pursuit velocity. Top row: Raw data. Bottom row: Data normalized with Box–Cox transformations and rescaled as Z-scores
Fig. 5
Fig. 5
Cumulative distributions of visual-tracking parameters. Left: SD of tangential errors. Right: Horizontal gain. Each filled circle represents a subject. The scale bars indicate the 95 % confidence interval of repeatability

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References

    1. Angelaki DE, Dickman JD. Premotor neurons encode torsional eye velocity during smooth-pursuit eye movements. Journal of Neuroscience. 2003;23:2971–9. - PMC - PubMed
    1. Bahill AT, McDonald JD. Smooth pursuit eye movements in response to predictable target motions. Vision Research. 1983;23:1573–83. doi: 10.1016/0042-6989(83)90171-2. - DOI - PubMed
    1. Barnes GR. Cognitive processes involved in smooth pursuit eye movements. Brain and Cognition. 2008;68:309–26. doi: 10.1016/j.bandc.2008.08.020. - DOI - PubMed
    1. Bartko JJ. The intraclass correlation coefficient as a measure of reliability. Psychological Reports. 1966;19:3–11. doi: 10.2466/pr0.1966.19.1.3. - DOI - PubMed
    1. Bartko JJ. Measurement and reliability: Statistical thinking considerations. Schizophrenia Bulletin. 1991;17:483–489. doi: 10.1093/schbul/17.3.483. - DOI - PubMed

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