Proprioception variables as determinants of lapsed time estimation.

It was postulated that increasing positional and force cues would provide more discriminable stimuli to serve as references for the reproduction of a motor response. The levels and mode of the proprioceptive feedback were varied during the coincident positioning task of moving a carriage along a trackway in 2·0 sec. In a balanced design with 80 Ss, 2 values of positional cues, moving the carriage over 2·5 or 65·0 cm, and 2 values of force cues, minimal resistance and 18·9 kg, produced 4 different feedback combinations. Significant learning occurred during 30 trials with knowledge of results (KB), and the combinations involving movement produced the greatest accuracy. Throughout 30 trials without knowledge of results (NoKR) the estimates produced by the movement only and weight only groups became longer, whilst the control group and the movement plus weight group did not drift. It was suggested that the group differences were caused by fatigue. Interpolated rests of 1 min between groups of 5 trials during the KB condition shortened the first post-rest trial whence performance was restored by the remaining 4 trials. During NoKB the first post-rest trial was again shorter, but since the remaining 4 were overestimated it was more accurate. In view of these results, apparently redundant movements might aid in timing tasks requiring temporal and spatial organization.