@article{ref1,
title="The role of feedback in manual tracking of visual targets",
journal="Perceptual and motor skills",
year="2000",
author="Hocherman, S. and Levy, H.",
volume="90",
number="3",
pages="1235-1248",
abstract="The role of visual feedback in manual tracking was investigated in 24 subjects who tracked 5-, 10-, and 40-mm/diameter targets, moving on a screen at 18 to 25 mm/sec., along various paths, by moving an unseen handle over a digitizing tablet. A cursor indicating instantaneous handle position was visible at all times on half the trials and hidden within a circle coaxial with the target but double its diameter in the other half. The handle had to be within the instantaneous target's digitizer-defined boundaries for the latter to keep moving. All tracking movements were segmented into small movement steps. A tendency to outrun the target was seen, indicating predictive control. Absence of visual feedback had negligible effect on movement velocity. Movement direction appeared to involve open-loop programming but improved significantly when subjects could see the cursor. Occasional corrective movements occurred only when visual feedback was given. Otherwise, a large positional error accumulates despite reasonable ability to control tracking direction.<p /><p>Language: en</p>",
language="en",
issn="0031-5125",
doi="",
url="http://dx.doi.org/"
}