The Effect of Physical Workload and Modality of Information Presentation on Cognitive Inhibition in Highly Fit Young Males

Abstract

OCCUPATIONAL APPLICATIONS This study presents an experiment assessing the interaction between physical task load and modality of information presentation on cognitive task performance. Results indicated that males of equivalent high fitness, between the ages of 18 and 25, can perform complex cognitive tasks reliably well while performing a concurrent physical task requiring up to 70% of aerobic capacity. Furthermore, results revealed that participants respond slightly more quickly to visual stimuli than auditory stimuli but are equally adept at inhibiting responses presented via either modality. These results are applicable to the design of information displays for information processing tasks as part of occupations requiring simultaneous worker physical performance, such as soldiers in combat situations, firefighters in emergency rescue, police officers in security patrols on foot, etc.TECHNICAL ABSTRACT Background: Many occupations require workers to perform cognitive tasks while concurrently performing a physical task, such as a soldier taking orders while running to a helicopter evacuation point or a firefighter navigating through a burning building. Diverse personal factors have been identified to influence the effect of physical workload on cognitive performance; however, the literature presents some contradictions, and findings appear heavily dependent on participant sample characteristics, physical task type, and cognitive task type. Purpose: The purpose of this study was to assess the interaction between physical workload and modality of information presentation on performance of a concurrent cognitive task by highly fit young males. Methods: Twenty-four highly fit males between the ages of 18 and 25 completed the experiment. Participants ran on a treadmill at one of three physical exertion levels (0%, 50%, and 70% of maximal oxygen uptake [VO₂max]). Levels were selected based on a previously-defined “optimal range” of 40%–55% VO₂max for facilitating concurrent cognitive performance. Participants were exposed to exertion below, within, or above the optimal range for 8 minutes in each trial while concurrently performing a stop-signal task with stimuli presented either visually or aurally. Accuracy, response time, stop-signal reaction time, and perceived cognitive workload were recorded. Results: Physical exertion level did not appear to have a significant effect on responses with the exception of a decrease in accuracy that approached significance (p < 0.10). Stimulus modality had a significant effect, with higher accuracy, lower response time, and lower stop-signal reaction time occurring with visual stimuli compared to auditory. The modality of the stop signal (an indicator that participants should inhibit a reaction) had no effect on any response. No significant interaction was found between physical exertion level and modality of information presentation on cognitive inhibition. Conclusions: Highly fit young males, when subjected to an acute bout of exercise requiring 70% VO₂max or less and lasting 8 minutes or less, exhibit no negative effects on cognitive inhibition performance, but response time appears faster with visual versus auditory stimuli.

Keywords:

• Multitasking
• physical exertion
• cognitive performance
• multi-modal displays

Funding

This research was supported in part by a grant from the National Institute of Occupational Safety and Health (number 2 T42 OH008673-08). The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the National Institute of Occupational Safety and Health.