Effects of kinesthetic information on working memory for 2D sequential selection task

In this paper, we study the effect of haptic information for memorizing an order of selecting positions scattered on a two-dimensional plane. The task was motivated by the need of an effective training system for a cell production line in manufacturing plants. We constructed a collocated visuo-haptic training system that covers the workspace of an adult arm, and implemented three training methods that varied in the degree of kinesthetic information provided to the trainee. The methods were visual display only, visual display with enactment, and visual display with haptic guidance. We experimentally assessed the training performances of the three methods in terms of the number of repeated trials necessary to memorize the order of 2D sequential selections, along with subjective evaluations. Overall, the method of visual display with enactment exhibited the best performance, whereas the method of visual display with haptic guidance the worst performance. These results indicate that enactment can improve the memory performance by presenting the information through the haptic sensory channel (in addition to the visual channel), but active guidance may prohibit such positive effects by making the trainee less focus on the training.