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Colin Downey, Griffin Pace, Larry Cormack, Scott Stevenson, Tracey Candy; Development of Pursuit of a Random Walk by Infants aged 4 to 17 Week. Journal of Vision 2018;18(10):784. doi: https://doi.org/10.1167/18.10.784.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: Pursuit eye movements develop rapidly during the first four months postnatally (Shea & Aslin, 1990) with increased gain and response duration (Phillips et al, 1997). Previous studies have used horizontal, sinusoidal motion of different speeds and amplitudes (Jacobs et al, 1997; von Hofsten & Rosander, 1996), but none have used a random unpredictable trajectory. This study documented development of pursuit movements of infants 4-17 weeks of age, using a cross-correlogram approach (Mulligan et al, 2013). Methods: Twelve infants and ten adults were presented with a white 4deg square moving randomly in velocity on a rear projection screen in horizontal, vertical, oblique, or 2-dimensional paths for 100s. Eye position was recorded binocularly using an Eyelink 1000 (SR Research) at 500Hz. Results: Cross-correlations between the stimulus and response positions and velocities demonstrated pursuit in infants as young as 4wks of age for horizontal and vertical profiles. Median adult latencies to peak correlation were 0.674sec (IQR: 0.638-0.715sec) for position and 0.708sec (IQR 0.670-0.755sec) for velocity, while the overall infants' medians were 1.07sec (IQR 0.328-1.432sec) for position and 1.07sec (IQR 0.152-1.370sec) for velocity. Median peak correlations were similar for adults across conditions (pos = 0.972, IQR 0.947-0.984; vel = 0.629, IQR 0.540-0.704), while median peak correlations were higher for infants for the 1-dimensional vertical and horizontal movements than the oblique and 2-dimensional movements (pos. = 0.912, IQR 0.751-0.942 (x&y); 0.818, IQR 0.502-0.874 (oblique); 0.414, IQR 0.137-0.770 (2D) & vel. = 0.399, IQR 0.242-0.462 (x&y); 0.286, IQR 0.215-0.328 (oblique); 0.234, IQR 0.184-0.299). Conclusion: These data indicate that infants as young as 4wks can pursue a random target motion, though with longer latency than adults and an apparent effect of trajectory complexity. Our longitudinal data suggest immaturities lasting beyond 17wks of age.
Meeting abstract presented at VSS 2018
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