In previous experiments in our lab we have concentrated on performance measures to evaluate the effects of secondary tasks on the driver. Secondary tasks are those performed in addition to driving, e.g. interacting with a personal navigation device. However, as Jackson Beatty has shown, when people’s cognitive load increases their pupils dilate  [2]. This fascinating phenomenon provides a physiological measure of cognitive load. Why is it important to have multiple measures of cognitive load? As Christopher Wickens points out [3] this allows us to avoid circular arguments such as “… saying that a task interferes more because of its higher resource demand, and its resource demand is inferred to be higher because of its greater interference.”

We found that in a driving simulator-based experiment that was conducted by Alex, performance-based and pupillometry-based (that is a physiological) cognitive load measures show high correspondence for tasks that lasted tens of seconds. In other words, both driving performance measures and pupil size changes appear to track cognitive load changes. In the experiment the driver is involved in two spoken tasks in addition to the manual-visual task of driving. We hypothesize that different parts of these two spoken tasks present different levels of cognitive load for the driver. Our measurements of driving performance and pupil diameter changes appear to confirm the hypothesis. Additionally, we introduced a new pupillometry-based cognitive load measure that shows promise for tracking changes in cognitive load on time scales of several seconds.

In Alex’s experiment one of the spoken tasks required participants to ask and answer yes/no questions. We hypothesize that different phases of this task also present different levels of cognitive load to the driver. Will this be evident in driving performance and pupillometric data? We hope to find out soon!

References

[1] Oskar Palinko, Andrew L. Kun, Alexander Shyrokov, Peter Heeman, “Estimating Cognitive Load Using Remote Eye Tracking in a Driving Simulator,” ETRA 2010

[2] Jackson Beatty, “Task-evoked pupillary responses, processing load, and the structure of processing resources,” Psychological Bulletin. Vol. 91(2), Mar 1982, 276-292

[3] Christopher D. Wickens, “Multiple resources and performance prediction,” Theoretical Issues in Ergonomic Science, 2002, Vol. 3, No. 2, 159-177

On Thursday we participated in the meeting’s demo session. We demonstrated the advantage of using voice commands to control a police radio over using the radio’s buttons. We used a single-computer driving simulator and a radio setup. Of course the first driving simulator experiment we published investigated this effect [1]. We also demonstrated accessing a remote database using the Project54 system running on a Symbol handheld computer. We expect that, once we get approval from the NH State Police to deploy such devices (NHSP is responsible for data access for all officers in the state), they will be a big hit with local departments.

One of the many people we had a chance to talk to at the TWG meeting is Gil Emery, Communications Manager at the Portsmouth, NH PD. Gil was interested in the handhelds and we may be able to work with him on using these handhelds as cameras that allow tagging pictures on the spot and then using a cellular network to transmit them to headquarters. This work would build on Michael Farrar’s MS thesis research.

You can see pictures from this event of Flickr.

References

[1] Zeljko Medenica, Andrew L. Kun, “Comparing the Influence of Two User Interfaces for Mobile Radios on Driving Performance,” Driving Assessment 2007

Oskar (center) and Mike (right)

Zeljko (center)

Oskar, Mike and I are working on expanding the multitouch study. We plan to start with an online study in which subjects will watch two videos, one in which a story is presented using the multitouch table and another with the same story presented using a simple slide show. Zeljko will head up the follow-on to the pilot study – take a look at the video below to see (roughly) what we’re planning to do.

Take a look at other pictures I took at Ubicomp 2009 on Flickr.

References

[1] Oskar Palinko, Ankit Singh, Michael A. Farrar, Michael Litchfield, Andrew L. Kun, “Towards Storytelling with Geotagged Photos on a Multitouch Display,” Conference Supplement, Ubicomp 2009

[2] Zeljko Medenica, Oskar Palinko, Andrew L. Kun, Tim Paek, “Exploring In-Car Augmented Reality Navigation Aids: A Pilot Study,” Conference Supplement, Ubicomp 2009

As part of my visit I saw the MERL driving simulator, which is an excellent adaptation of a computer game for research purposes (read more about it in Garrett and Bret’s Automotive UI 2009 paper). I really like the driving courses that they can use (e.g. winding mountain roads and narrow village streets) and I’m impressed with the performance of the simulator’s chair which shakes and tilts.

After the simulator tour I gave a talk on our latest navigation study, which compared driving performance and visual attention when using two personal navigation aids: one that displays a map and provides spoken instructions and another that provides spoken instructions only. The talk was based on our Automotive UI 2009 paper.

Finally, I had a chance to talk to Fatih Porikli, who showed me some great videos of his work on recognizing pedestrians. We also discussed possible collaboration on learning grammars for using voice commands to tag photos. More about this in another post.