Because spatial disorientation (SD) is a serious threat for pilots, considerable effort has been put into designing SD countermeasures. The present study evaluates the effectiveness of a tactile torso display as a countermeasure to SD and compares inside-out and outside-in codings. The tactile display consists of a matrix of vibrating elements covering large parts of the pilot's torso and is believed to present spatial information in an intuitive way. In this study, a total of 24 participants were assigned to the two coding groups. A rotating chair was used 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. 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. These findings demonstrate the potential of tactile cockpit instruments in controlling SD, even in the presence of strong but erroneous self-motion information from the vestibular sense.
Abstract