Road Sign Reaction Time Test

Background

The Road Sign Test (RST) is a computerized cognitive-behavioral assessment test to measure how quickly a driver perceives, identifies, and responds to traffic signs. Jerri D. Edwards and colleagues describe the procedure - originally published by Karlene Ball and Cynthia Owsley in 2000- in their 2006 paper on normative data for the Useful Field of View Test (UFOV) in older participants. Edwards and colleagues used the RST as an additional measure of processing speed and visual attention to compare to their participants' performance on the UFOV.

The RST requires participants to use a computer mouse to respond to four different road signs: a bike sign, a pedestrian sign, and a left and right turn sign. Each sign requires a different response: the bike sign requires a left button press, the pedestrian sign requires a right button press, the left turn sign requires participants to actively move the mouse to the left and the right turn sign requires participants to move the mouse to the right. After practicing the different responses, the actual test 'hides' the target road sign within a set of 3 or 6 road signs that are all crossed out by a red cross. Only after a random delay, is the red cross removed from one of the signs (the target) and participants need to respond to it as quickly as possible.

The Millisecond Road Sign Test (MS-RST) adapts the procedure to touchscreens. Instead of using mouse button presses and moving the mouse, participants are asked to move a car icon left and right or press dedicated 'Stop' icons for bicycles and pedestrians. The MS-RST works on touchscreen as well as regular computer screens with an attached mouse. The procedure is otherwise the same as for the RST.

Task Procedure

Both the RST and the MS-RST begin with a response practice to the four different road signs (bicycle, pedestrian, left and right turn signs). The response practice round runs 20 trials and presents only 1 sign at a time (5 trials per sign). The order of the signs presented is randomized. During the response practice only correct responses terminate a trial. If no valid response is detected within 5 seconds, a response reminder -with a summary of possible responses- is presented on screen. After the first round of 20 trials, the script checks performance. If performance is below 90% correct, the response practice is repeated once. If response practice is still below cut-off after the second round, the entire test is terminated.

After response practice, participants work through a 12-trial task practice to familiarize participants with the actual task set up. During task practice, participants are only presented with 2 signs that are randomly assigned to two of 12 possible screen locations. Each of the four signs is presented as a target 3 times and 3 times as a distractor. The order of targets is randomized. The two signs are crossed out with a red cross for 1-6 seconds, before the cross is removed from one of the signs, and participants are required to respond with the corresponding response. During the task practice, participants receive feedback.

After the task practice round, the actual testing session begins. The default set up of the script runs the two test blocks in a blocked design but allows researchers to switch to a mixed design. The default set up first runs the level 3 block with 12 trials (presenting three road signs) before running the level 6 block with 12 trials. During level 6 trials, two road signs are repeated. It is randomly determined which signs are repeated. Participants receive no performance feedback during testing.

What it Measures

The Road Sign Test (RST) is a measure of rule-based decision-making speed and visual attention

Psychological domains

• Processing Speed: Ability to quickly perceive a stimulus, process the information, and initiate a response
• Decision Making: Choosing the correct response from multiple alternatives.
• Selective Attention: Ability to discriminate between different stimuli and select the correct one
• Sustained Attention: Ability to maintain focus and quickly adapt one's behavior to current demands

Main Performance Metrics

• Response Times: correct response times (in ms) to target presentation; main measure of rule-based decision-making speed
• Accuracy: proportion correct responses

Psychiatric Conditions

Various variants of the RST are used in assessments of 'driving fitness'

• *Mild Cognitive Impairment (MCI)
• Early-stage Alzheimer's disease (AD)
• Parkinson's Disease (PD)
• Stroke

Test Variations

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Road Sign Reaction Time Test.

---

Owsley, C., Burton-Danner, K., & Jackson, G. (2000). Aging and Spatial Localization during Feature Search. Gerontology, 46(6), 300-305.

Sims, Jr, Allman, Ball, & Owsley. (2000). Exploratory study of incident vehicle crashes among older drivers. The Journals of Gerontology, 55b(1), M22-7.

Ball K. & Owsley C. (2000) Increasing mobility and reducing accidents of older drivers. In: Mobility and Transportation in the Elderly (eds Schaie K.W. & Pietrucha M.), pp. 213–251. Springer Publishing Company, New York, USA.

Ball, K., Berch, Helmers, Jobe, Leveck, Marsiske, . . . For the Active Study Group. (2002). Effects of Cognitive Training Interventions With Older Adults: A Randomized Controlled Trial. JAMA, 288(18), 2271-2281.

Edwards, J., Ross, L., Wadley, V., Clay, O., Crowe, M., Roenker, D., & Ball, K. (2006). The useful field of view test: Normative data for older adults. Archives of Clinical Neuropsychology, 21(4), 275-286.

Fazeli, Pariya L., Ross, Lesley A., Vance, David E., & Ball, Karlene. (2013). The relationship between computer experience and computerized cognitive test performance among older adults. The Journals of Gerontology, Series B, 68(3), 337-346.