The effects of time and distance on accuracy of target-directed locomotion: does an accurate short-term memory for spatial location exist?

The present study was an attempt to replicate the findings of an influential set of experiments by Thomson (1980, 1983) in which he demonstrated a highly accurate but transitory short-term memory for target location during locomotion. No evidence of Thomson's rapidly decaying 8 s short-term memory was found in either of the two experiments presented here. The distance to the target, not the elapsed time, was found to be the major variable affecting the accuracy of walks made without the benefit of visual feedback; as target distance increased so did locomotor error. Increasing the elapsed time to more than 8 s between viewing the target and reaching the vicinity of the target had no effect on the accuracy of walks made with eyes closed. When the elapsed time was greater than 30 s, however, performance began to deteriorate. These results suggest, in sharp contrast to Thomson's experiments, that short-term memory for target location decays rather slowly during locomotion. In this regard, short-term memory in locomotor tasks appears to be little different from the kinds of short-term memory associated with other motor acts.