Cognitive Workload Impacts of Simulated Visibility Changes During Search and Surveillance Tasks Quantified by Functional Near Infrared Spectroscopy

Abstract

Functional near infrared spectroscopy (fNIRS) enables investigation of hemodynamics and cortical activation in lab and field settings. Studies utilizing fNIRS in realistic complex environments are limited, and studies with real-time applications often lack the accompaniment of realistic settings or scenarios. Investigations of neuronal activation focused on improving human performance during complex and cognitively taxing tasks, like those experienced by unmanned aerial systems sensor operators, have yielded a knowledge gap regarding studies with ecological validity, and distinction between condition difficulties. This gap resulted from limitations in experimental design to account for realistic experiences within dynamic environments, missing fundamental transitional load details of realistic cognitive tasks. This article sought to evaluate cognitive workload in conjunction with behavioral task performance in novice sensor operators. During the experimental protocol, operators engaged with complex tasks under distinct task load conditions, implemented using a high-fidelity simulator and changes in time of day. Linear mixed effects models and multiple contrast post hoc results confirmed that simulated time-of-day visibility changes effectively modulated task load, with distinctions between easy, medium and hard conditions. Using a visibility through changes in time of day paradigm is an effective method for mimicking real-life conditions of sensor operators; however, disengagement may occur if subjects are not adequately trained.