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For multiple degree-of-freedom (DOF) systems, it is important to determine how accurately operators can control each DOF and what influence perceptual, information processing, and psychomotor components have on performance. Sixteen right-handed male students participated in 2 experiments: 1 involving positioning and 1 involving tracking with 3 translational DOFs. To separate perceptual and psychomotor effects, we used 2 control-display mappings that differed in the coupling of vertical and depth dimensions to the up-down and fore-aft control axes. We observed information processing effects in the positioning task: Initial error correction on the vertical dimension lagged in time behind the horizontal dimension. The depth dimension error correction lagged behind both, which was ascribed to the poorer perceptual information. We observed this perceptual effect also in the tracking experiment: Tracking error along the depth dimension was 3.8 times larger than along the other dimensions. Motor effects were also present, with tracking errors along the up-down axis of the hand controller being 1.1 times larger than along the fore-aft axis. These results indicate that all 3 components contribute to control performance. Actual applications of this research include interface design for remote control and virtual reality.

Objective: We investigated the effectiveness of a tactile torso display as a counter-measure to spatial disorientation (SD) and compared inside-out and outside-in codings. Background: SD is a serious threat to military as well as civilian pilots and aircraft. Considerable effort has been put into SD countermeasures such as training programs and advanced cockpit displays. Tactile displays have been considered a promising technology. Method: Twenty-four participants were assigned to the two coding groups (12 per group and matched for age and gender). We used a rotating chair to build up a state of SD by rotating participants around their yaw axis followed by a sudden stop. During the following recovery phase a random disturbance signal was added to the chair's orientation. Participants actively controlled their orientation and were instructed to maintain a stable orientation. Results: Statistical analyses revealed that recovery from SD was improved with support of the tactile instrument, but tracking performance was reduced. The effects were the same whether the instrument was available full time or during the recovery phase only. There were no differences between outside-in and inside-out coding. Conclusion: The present study demonstrates the potential of tactile cockpit instruments in controlling SD, even in the presence of strong but misleading self-motion information from the vestibular sense. Application: Actual or potential applications of this research include spatial disorientation countermeasures for pilots, divers, and astronauts.