RT Journal Article
SR Electronic
T1 Effects of delayed visual information on the rate and amount of prism adaptation in the human
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 7644
OP 7652
DO 10.1523/JNEUROSCI.15-11-07644.1995
VO 15
IS 11
A1 S Kitazawa
A1 T Kohno
A1 T Uka
YR 1995
UL http://www.jneurosci.org/content/15/11/7644.abstract
AB Accurate reaching towards a visual target is initially disturbed when the visual field is displaced by prisms, but recovers with successive trials. To determine how the improvement depends on the visual error signals associated with the motor output, the time course of prism adaptation was studied with delayed visual information on the error. Subjects were trained to reach rapidly at a target on a tangent screen. Vision was always blocked during the movement, and allowed again only after the index finger touched the screen. One experiment consisted of three sets of 30 trials. In the first set, the subject wore no prisms and vision was allowed without delay. In the second, the visual field was displaced by prisms, and vision was available only after a delay period of 0–10,000 msec while the subjects maintained their final pointing position. Initially, the subject misreached the target by about the amount of visual displacement (60 mm). Errors decreased with trials by an amount proportional to the error in the preceding trial. The rate of decrease of error was generally largest when the delay was 0 msec, became significantly smaller when the delay was 50 msec, and showed only gradual change with longer delays. In the third set, the subject wore no prisms and vision was allowed without delay. Initial misreaching in the direction opposite to the visual displacement, reflecting the amount of adaptation in the second set, was generally largest with no delay (median of 46 mm) and significantly smaller with 50 msec and longer delays (17–33 mm).(ABSTRACT TRUNCATED AT 250 WORDS)