Experimental Programs: Human Factors

Research

Patricia R. DeLucia [Faculty Page]

My research program focuses on theoretical and applied issues in visual perception and human factors. My primary interests include the perception of collision, motion, and depth; patient safety, performance in nursing. Human-factors applications include transportation safety (driving and aviation), virtual reality, night vision goggles, sport, and human factors in medicine (minimally-invasive surgery; patient safety; performance in nursing). For example, your decision of when to swing the bat at the ball is a perceptual judgment about when the ball will hit the bat, known in the literature as a judgment of time to contact (TTC). It has been shown that TTC is available in the two-dimensional pattern of light that reaches the eye or optic flow, or tau. Tau-based models of performance have been highly influential and raise doubts about traditional (cognitive) theories of depth perception because they do not require mental processes or pictorial depth cues. My research demonstrates that depth cues and cognitive processes can influence TTC judgments despite the presence of tau. Similarly, to avoid a rear-end collision, drivers must detect that the car ahead of them is decelerating. Our research indicates that the type of information that drivers use to detect deceleration depends on how far ahead the lead car is located. This suggests that the processes that underlie space perception depend on distance. Finally, in other research examined whether three separate views of space—a top view, frontal view, and side view, would improve perceptual-motor performance. Results show that observers relied upon the top view and did not utilize the other views. Our most recent work in this areas suggests that the multiple displays that surgeons use in the already cluttered operating room can be integrated into one split-screen display without a detrimental effect on performance.

Keith S. Jones [Faculty Page]

My students and I research basic and applied aspects of the interaction between people and technology in diverse domains. Our research has been influenced by James J. Gibson's ecological approach to perception, as well as others who share a systems-oriented approach to human factors psychology. Our research revolves around two Gibsonian concepts:

(1) Direct vs. Indirect Perception. Gibson (1979/1984) argued that direct perception is not mediated by cognitive processes, whereas indirect perception stems from cognition. Given this distinction, we have studied distance estimation training programs, which are generally very cognitive. Our work demonstrated that the typical way to train distance estimation degraded the performance of an action that would normally be guided by direct perception.

(2) Affordance Perception. Gibson (1977) stated “the affordance of anything is a specific combination of the properties of its substance and its surfaces taken with reference to an animal” (p. 67). For example, an aperture’s pass-through-ness depends on its size relative to the size of the individual trying to pass through it. With this in mind, we are conducting two lines of human-robot interaction research. First, we study why operators got tele-operated robots stuck in apertures. Our initial work demonstrated that operators understood whether the robot was smaller or larger than an aperture, and that operators were sometimes unable to drive the robot through apertures that were wider than the robot. Consequently, we suggested that operators must base decisions to enter apertures on their ability to control the robot. However, subsequent work demonstrated that operators could not do so. Future research will examine ways to overcome this limitation. Second, we study how people judge whether another person can perform a given action. Given that knowledge, we will program robots to perceive the affordances for a human.

Martina Klein (Dr. Klein will be joining the department in Fall 2009)

My research focuses on operators' mental stress and mental workload in the laparoscopic surgery environment. Laparoscopic surgery entails that the target tissue is portrayed on a monitor from a camera located inside the patient's body and physicians use long thin instruments that are partially inserted into the patient's body to perform the surgery. This environment results in reduced depth information-the three dimensional surgical field is reduced to two dimensions when it is portrayed on the monitor. Further, since physicians have to view the surgical field from the camera's perspective rather than their eyes' perspective, the normal mapping between the hands and the eyes is disrupted in this environment. My research has shown that the perceptual-motor challenges inherent in laparoscopic surgery induce mental stress and mental workload in novices. In the future, I anticipate studying the influences of surgical training and stereoscopic depth displays on surgeons' experience of mental stress and mental workload in the laparoscopic surgery environment.