With recent advances in workstation technology, operators are often asked to perform complex tasks that require a tremendous amount of real-time information processing. In order to avoid poor task performance due to the operators cognitive limitations, it would be advantageous to be able to probe an operators cognitive state while performing such tasks. The current study investigates whether operators exhibit changes in seated posture as a result of changing cognitive task conditions. Furthermore, the current study presents means of quantifying such seated postural changes in real-time and uses these measures to construct an implicit cognitive state gauge.
Fourteen subjects performed a simulated airspace monitoring task in which they tracked multiple 75.0 sec long waves of incoming aircraft with various levels of difficulty. Subjects were instructed to identify all incoming aircraft and to attend to them based on the level of threat that they posed. While performing the task, subjects seated postural changes were monitored by tracking the distribution of pressure over the seat and back pads of the chair. This distribution of pressure was used to calculate changes in seated center of pressure, seat torsion, and the extent to which subjects used the back of the chair to brace themselves.
Subjects demonstrated a significant decrease in seated postural changes over the course of more difficult waves (high number of aircraft on screen) in comparison to easier waves (low number of aircraft on screen). When subjects completed waves with 24 tracks on screen compared to waves with 6 tracks on screen, the distance traveled by the seated center of pressure decreased 40.3%, transverse-plane seat torsion decreased 32.2%, and the total change in distance between the left and right ischial tuberosities decreased 38.1% on average. The extent to which subjects postural changes were correlated to the changing number of tracks on screen was consistently high while the number of tracks on screen was increasing and was consistently low after the maximum number of tracks on screen had been presented. It was concluded that monitoring seated posture is effective for gauging how subjects update their awareness of task conditions in real-time.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-09182006-110726 |
| Date | 31 January 2007 |
| Creators | Frank, Gregory Richard |
| Contributors | Donald H. McBurney, Mark S. Redfern, Carey Balaban |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-09182006-110726/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0015 seconds