TY  - JOUR
PY  - 2000//
TI  - The role of feedback in manual tracking of visual targets
JO  - Perceptual and motor skills
A1  - Hocherman, S.
A1  - Levy, H.
SP  - 1235
EP  - 1248
VL  - 90
IS  - 3
N2  - 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>
LA  - en
SN  - 0031-5125
UR  - http://dx.doi.org/
ID  - ref1
ER  -