"That's ideal to have somebody with both sets of skills. That's pretty rare," Kramer said.

"And Hank's great with hardware." Neider said the pedestrian distraction study had its origins almost a year before when he, Kramer, and McCarley were "throwing out ideas" for new research topics involving divided attention. Kramer said the number of recent accidents on campus involving pedestrians and vehicles seemed like a good topic, both for study and for potentially helping with prevention.

With cell phone usage a necessary fact of life for most people, and music players like iPods a common sight on city streets, the topic of pedestrian distraction is one that is just starting to reach the public consciousness. In New York a bill has been proposed to ban listening to iPods or talking on a cell phone while crossing the street.

"That's where I'm from and it's a wild world there," Neider said. "But there are times when the driver is doing his job and somebody just walks out in front of a car and it happens. There is a big debate starting to grow about this right now, so we are hoping to provide some informed research."

Neider has done mostly theoretical work in the area of visual cognition, specifically in terms of visual search, but this project involves more applied work than his past research. He said the study has multiple goals, and one of them is to extend basic theory regarding attention. Neider said that much of what is known about cognition and attention comes from inferences made from experiments with simple, artificial tasks.

"The problem with that is that the real world is much different than sitting in front of a computer looking at things like a T and an L, which is a classic visual search paradigm," he said. "So the idea here was to start looking at attention, and in this case divided attention because this is a divided attention task, and how what we know about attention from simple tasks translates into a much more realistic scenario where there are a lot of things competing for attention and the task is much more complex."

Thanks to the capabilities of the CAVE and the experiment's designers, the pedestrian distraction study will offer a setting that is more naturalistic and have much more realistic tasks for test subjects to perform. Kramer said the pedestrian study will seek to learn detailed information about how pedestrians negotiate traffic while performing other tasks.

"We want, first of all, to understand the extent to which people can walk safely and navigate busy streets and do other things like listen to an iPod or talk on a cell phone and so forth," Kramer said. "And we want to quantify what the costs are in terms of walking speed or how closely they get to vehicles, when they step off the curb, and how they judge gaps in traffic because we do that all the time."

One of the places on campus that pedestrians and drivers of vehicles are asked by flashing lights and signs to regard each other with an eye toward safety is the crossing on Springfield between Wright and Mathews. That crossing will look familiar to test subjects in the CAVE who are participating in the pedestrian distraction study because Crowell said that is the crossing he had in mind when he was putting together the experiment. The building that is visible to test subjects in the CAVE isn't the nearby Grainger Engineering Library to the south, however, or the Digital Computer Laboratory to the north. Too many trees and other obstacles surrounding them for a clean image, Crowell said.

When he was putting together the experiment Crowell took a walk around campus to scout useful scenes to photograph for the images required on the display screens. He found his building in the new (and as yet treeless or shrub-less) addition to the Micro and Nanotechnology Laboratory just south of Beckman. The virtual crossing has a black asphalt look with wide white stripes just like the one on Springfield, but doesn't include that crossing's flashing lights. No help for the distracted pedestrians, Crowell says.

While the CAVE is now open for business for other perceptual psychology experiments, the first such study done in it won't likely be the last for this line of research. Kramer and Neider discussed other potential experiments involving the CAVE and the treadmill, such as studies involving older adults.

"I would feel pretty confident in saying we will get more than one paper from this," Neider said.