Evidence Supporting Open-Loop Control During Early Vergence

  • John Semmlow Rutgers University
  • Tara Alvarez New Jersey Institute of Technology
  • Bérangère Granger-Donetti Essilor International
Keywords: vergence, initial component, fast component, open-loop, preprogrammed


Disparity vergence eye movements were analyzed to determine if the early component of this response operates under open-loop, or preprogrammed, control. The analysis compares ratios of peak velocity to response amplitude (i.e., main sequence ratios) for the isolated early component and for the entire disparity vergence response. The stimuli were limited a 4 deg step changes in vergence so that any differences in movement dynamics (i.e., peak velocities) were due only to internal noise. Nine binocularly normal subjects were studied. A significant correlation between peak velocity and amplitude was observed during the early portion of the movement (p < 0.002), but not for the overall vergence response. Results support the widely held, but unproven assumption that the early component of symmetrical vergence is guided by open-loop, or preprogrammed, control processes while the overall response is influenced by internal and/or external feedback.
How to Cite
Semmlow, J., Alvarez, T., & Granger-Donetti, B. (2013). Evidence Supporting Open-Loop Control During Early Vergence. Journal of Eye Movement Research, 6(4). https://doi.org/10.16910/jemr.6.4.2