Increased cognitive load leads to impaired mobility decisions in seniors at risk for falls

Abstract

Successful mobility requires appropriate decision-making. Seniors with reduced executive functioning-such as senior fallers-may be prone to poor mobility judgments, especially under dual-task conditions. We classified participants as "At-Risk" and "Not-At-Risk" for falls using a validated physiological falls-risk assessment. Dual-task performance was assessed in a virtual reality environment where participants crossed a simulated street by walking on a manual treadmill while listening to music or conversing on a phone. Those "At-Risk" experienced more collisions with oncoming cars and had longer crossing times in the Phone condition compared to controls. We conclude that poor mobility judgments during a dual-task leads to unsafe mobility for those at-risk for falls.

Figure 1

A screen-shot of the virtual reality display. Note that the image was created from still captures of three separate images projected on the three walls of the CAVE (left, straight ahead, and right). In the virtual environment, the road appears as one straight line, perpendicular to the participant. Reprinted from “Pedestrians, vehicles, and cell phones,” by M. B. Neider, J. S. McCarley, J. A. Crowell, H. Kaczmarski, and A. F. Kramer, 2010, Accident Analysis and Prevention, 42, pp. 589–594. Copyright 2010 by Elsevier. Reprinted with permission.

Figure 2

Street crossing performance as a function of condition (No distraction, Music, and Phone) and falls-risk group. Error bars represent standard errors of the mean. (a) Mean number of trials successfully completed. Those “At-Risk” for falls successfully crossed the street significantly fewer times than those “Not-At-Risk” in the Phone condition. (b) Mean length of time taken to cross the street on successful trials. Those “At-Risk” for falls crossed the street significantly slower than those “Not-At-Risk” in the Phone condition.