1. Introduction
nausea, headaches
ADVERSE EFFECTS
Augmented reality (AR) has been shown to improve productivity in industry, but its adverse effects (e.g., headaches, eye strain, nausea, and mental workload) on users warrant further investigation. The objective of this study is to investigate the effects of different instruction methods (i.e., HoloLens AR-based and paper-based instructions) and task complexity (low and high-demanding tasks) on cognitive workloads and performance. Twenty-eight healthy males with a mean age of 32.12 (SD 2.45) years were recruited in this study and were randomly divided into two groups. The first group performed the experiment using AR-based instruction, and the second group used paper-based instruction. Performance was measured using total task time (TTT). The cognitive workload was measured using the power of electroencephalograph (EEG) features and the NASA task load index (NASA TLX). The results showed that using AR instructions resulted in a reduction in maintenance times and an increase in mental workload compared to paper instructions, particularly for the more demanding tasks. With AR instruction, 0.45% and 14.94% less time was spent on low- and high-demand tasks, respectively, as compared to paper instructions. According to the EEG features, employing AR to guide employees during highly demanding maintenance tasks increased information processing, which could be linked with an increased germane cognitive load. Increased germane cognitive load means participants can better facilitate long-term knowledge and skill acquisition. These results suggested that AR is superior and recommended for highly demanding maintenance tasks since it speeds up maintenance times and increases the possibility that information is stored in long-term memory and encrypted for recalls.The overall complexity of maintenance and assembly tasks grows as product mass customization increases [Traditionally, instructions for maintenance tasks are delivered to workers on paper with expert assistance [The recent developments in interactive multimedia mediums provide promising solutions for the weaknesses and limitations of the traditional paper-based instruction method. For instance, augmented reality (AR) technology is a powerful tool that overlays virtual information produced by computers into a real environment, which promotes experience and interaction [Cognitive load is defined as “the amount of cognitive effort being put into working memory at any particular time” [In comparison with traditional training methods, previous researchers focused mainly on the effectiveness of AR as a training or guiding tool based on task completion time and success rate. Previous research has shown that presenting task instructions via an AR display reduced errors and time to complete tasks while maintaining high levels of technology acceptance from operators [The electroencephalogram (EEG) is an emerging, noninvasive, affordable, and portable neuroimaging modality used to record voltage fluctuations occurring as ionic current flows inside the brain’s neurons [Previous studies have utilized EEG trends in various frequency bands to evaluate the cognitive characteristics of performance in different fields. Sassaroli et al. [This study aims to advance the body of knowledge relative to evaluating cognitive workload while using AR systems in the training of maintenance and assembly tasks. To accomplish this goal, both subjective and objective measurement methodologies are considered to evaluate cognitive workload during real-world representations of maintenance tasks. Therefore, the main objective of this study is to investigate the effects of different instruction methods (AR-based and paper-based instruction) and task complexity on cognitive workload and performance. The cognitive workload is evaluated by the EEG power spectrum density of alpha, beta, and theta in the frontal, central, occipital, temporal, and parietal brain regions and by perceived workload (NASA-TLX). The current study seeks to answer the following question: how do AR-based instruction methods with various demanding tasks affect human cognitive load (i.e., brain activity and perceived workload) and performance (completion time)? It was hypothesized that performing the experimental maintenance tasks with AR-based instructions would be linked with a higher cognitive load as participants must simultaneously attend to information in both real and virtual form. Yet, it was also anticipated that AR-instructions would improve performance time since they facilitate easier information availability as compared to traditional instructions.