Differences In Mental Workload Research Articles

A-123 Problem Solving and Mental Workload in Binge and Non-Binge Drinking College Students

Abstract Objective: Chronic sustained alcohol abuse is known to impact cognitive functioning. We examined potential differences in problem solving ability and mental workload in a more short-term population, binge-drinking college students. Method: Binge-drinking (BD) (n = 129) and non-binge-drinking (NBD) (n = 163) college students completed a computerized test of problem solving, a 3-disk and 4-disk version of the Tower of Hanoi (TOH). After each TOH session, they also completed an assessment of mental workload via the NASA-Task Load Index (NASA-TLX). Mental workload was defined as the Mental Demand subscale of the NASA-TLX. Results: No significant group difference was found in mean number of moves to complete the TOH in either the 3-disk version or 4-disk version. For mental workload, no difference was evident for the 3-disk TOH (BD M = 28.81, SD = 21.05 vs NBD M = 27.09, SD = 21.59, p = 0.497), but there was a difference for the 4-disk TOH condition (BD M = 47.22, SD = 21.86 vs NBD M = 41.84, SD = 22.94, p = 0.044). Conclusion(s): While no group differences in test performance were evident, there was a difference in mental workload on the more difficult TOH condition. We propose that mental workload, which is not normally considered in neuropsychology, might be a valuable tool in assessment of cognitive status, especially when there are subtle cognitive differences. In this case, even with similar test performance, cognitive status might not necessarily be the same between the two groups, with the BD group showing greater mental workload.

Influence of Increasing Task Complexity and Use of Informational Assistance Systems on Mental Workload.

(1) Background: Cognitive aspects and complexity in modern manual mixed model assembly are increasing. To reduce mental workload (MWL), informational assistance systems are introduced. The influence of complexity and used assistance system on MWL should be investigated to further improve the implementation of such assistance systems. (2) Methods: Using a simulated close to real-life assembly task a 2 × 3 design was chosen, with two levels of assembly complexity (within subjects) and three different assistance systems (paper, Augmented Reality (AR)-glasses, tablet–between subjects). MWL was measured using either physiological response (electrocardiogram (ECG) and eye-tracking) or performance indicators. (3) Results: An influence of task complexity on MWL can be shown. Additionally, usability based differences between the used assistance systems become more evident with reference to the results of area of interest analysis. (4) Conclusions: Using a multi-modal measurement approach, it is possible to detect complexity-based differences in MWL. Additional research on validity and alignment is needed to further use these for (neuro-) ergonomic considerations and recommendations.

Assessment of Implicit and Explicit Measures of Mental Workload in Working Situations: Implications for Industry 4.0

Nowadays, in the context of Industry 4.0, advanced working environments aim at achieving a high degree of human–machine collaboration. This phenomenon occurs, on the one hand, through the correct interpretation of operators’ data by machines that can adapt their functioning to support workers, and on the other hand, by ensuring the transparency of the actions of the system itself. This study used an ad hoc system that allowed the co-registration of a set of participants’ implicit and explicit (I/E) data in two experimental conditions that varied in the level of mental workload (MWL). Findings showed that the majority of the considered I/E measures were able to discriminate the different task-related mental demands and some implicit measures were capable of predicting task performance in both tasks. Moreover, self-reported measures showed that participants were aware of such differences in MWL. Finally, the paradigm’s ecology highlights that task and environmental features may affect the reliability of the various I/E measures. Thus, these factors have to be considered in the design and development of advanced adaptive systems within the industrial context.

Human-Robot Interaction with Drones and Drone Swarms in Law Enforcement Clearing Operations

Police officers often must work alone in clearing operations, a procedure that involves surveying a building for threats and appropriately responding. A partnership between drone swarms and officers has potential to increase the safety of officers and civilians during these high-stress operations and reduce the risk of harm from hostile persons. This two part study examines aspects of trust, situational awareness, mental demand, performance, and human-robot interaction during law enforcement building clearing operations using either a single drone or a drone swarm. Results indicate that single drone use can increase time for operation, but accuracy and safety of clearing is enhanced. Single drone use saw increased situational awareness, a decrease in number of targets missed, and a moderate level of trust. For drone swarms, results indicate significant differences in mental workload from swarm data feeds compared to single drone feeds but no substantial difference in accuracy of finding targets.

Differences in mental workload between traditional and single-incision laparoscopic procedures measured with a secondary task

IntroThe mental workload associated with laparoscopic suturing can be assessed with a secondary task that requires the same visual-spatial attentional resources. The purpose of this study was to use a secondary task to measure the incremental workload demands of single-incision laparoscopic surgery (SILS) procedures versus traditional laparoscopic procedures. Method12 surgery residents and surgical assistants who had met FLS criteria on an FLS and SILS simulator performed one trial each of peg transfer, cutting, and intracorporeal suturing tasks simultaneously with the secondary task and provided subjective workload ratings using the NASA-TLX. ResultsSILS procedures resulted in lower primary and secondary task scores, p < 0.001 and higher workload ratings, p < 0.0001. Suturing resulted in lower primary (p < 0.003) and secondary task scores (p < 0.017) and higher workload ratings (p < 0.017) compared to the other tasks. ConclusionsSILS procedures were significantly more mentally demanding than traditional laparoscopic procedures corroborated by primary and secondary tasks scores and subjective ratings.

Somatotopical feedback versus non-somatotopical feedback for phantom digit sensation on amputees using electrotactile stimulation.

BackgroundTranscutaneous electrical stimulation can provide amputees with tactile feedback for better manipulating an advanced prosthesis. In general, there are two ways to transfer the stimulus to the skin: somatotopical feedback (SF) that stimulates the phantom digit somatotopy on the stump and non-somatotopical feedback (NF) that stimulates other positions on the human body.MethodsTo investigate the difference between SF and NF, electrotactile experiments were conducted on seven amputees. Electrical stimulation was applied via a complete phantom map to the residual limb (SF) and to the upper arm (NF) separately. The behavior results of discrimination accuracy and response time were used to examine: 1) performance differences between SF and NF for discriminating position, type and strength of tactile feedback; 2) performance differences between SF and NF for one channel (1C), three channels (3C), and five channels (5C). NASA-TLX standardized testing was used to determine differences in mental workload between SF and NF.ResultsThe grand-averaged discrimination accuracy for SF was 6% higher than NF, and the average response time for SF was 600 ms faster than NF. SF is better than NF for position, type, strength, and the overall modality regarding both accuracy and response time except for 1C modality (p<0.001). Among the six modalities of stimulation channels, performance of 1C/SF was the best, which was similar to that of 1C/NF and 3C/SF; performance of 3C/NF was similar to that of 5C/SF; performance of 5C/NF was the worst. NASA-TLX scores indicated that mental workload increased as the number of stimulation channels increased.ConclusionsWe quantified the difference between SF and NF, and the influence of different number of stimulation channels. SF was better than NF in general, but the practical issues such as the limited area of stumps could constrain the use of SF. We found that more channels increased the amount and richness of information to the amputee while fewer channels resulted in higher performance, and thus the 3C/SF modality was a good compromise. Based on this study, we provide possible solutions to the practical problems involving the implementation of tactile feedback for amputees. These results are expected to promote the application of SF and NF tactile feedback for amputees in the future.

Sensitivity of Physiological Measures for Detecting Systematic Variations in Cognitive Demand From a Working Memory Task

To assess the sensitivity of two physiological measures for discriminating between levels of cognitive demand under driving conditions across different age groups. Previous driving research presents a mixed picture concerning the sensitivity of physiological measures for differentiating tasks with presumed differences in mental workload. A total of 108 relatively healthy drivers balanced by gender and across three age groups (20-29, 40-49, 60-69) engaged in three difficulty levels of an auditory presentation-verbal response working memory task. Heart rate and skin conductance level (SCL) both increased in a statistically significant fashion with each incremental increase in cognitive demand, whereas driving performance measures did not provide incremental discrimination. SCL was lower in the 40s and 60s age groups; however, the pattern of incremental increase with higher demand was consistent for heart rate and SCL across all age groups. Although each measure was quite sensitive at the group level, considering both SCL and heart rate improved detection of periods of heightened cognitive demand at the individual level. The data provide clear evidence that two basic physiological measures can be utilized under field conditions to differentiate multiple levels of objectively defined changes in cognitive demand. Methodological considerations, including task engagement, may account for some of the inconsistencies in previous research. These findings increase the confidence with which these measures may be applied to assess relative differences in mental workload when developing and optimizing human machine interface (HMI) designs and in exploring their potential role in advanced workload detection and augmented cognition systems.

Adaptation Longitudinal Driving Behavior, Mental Workload, and Psycho-Spacing Models in Fog

Adverse weather conditions have a substantial effect on traffic flow. However, the adaptation effects in longitudinal driving behavior that underlie this impact are unclear, as are the determinants. A driving simulator experiment was performed with a repeated-measures design and 25 participants. The adaptation effects in actual longitudinal driving behavior and the physiological indicators of mental workload (i.e., heart rate and heart rate variability) were measured under two conditions: normal visibility and fog. Significant adaptation effects in longitudinal driving behavior and a significant increase in mental workload were observed. A new estimation method was used to investigate the extent to which fog influenced the position of so-called action points in the (Δv, s) plane of a psycho-spacing model, where Δv was relative speed and s was spacing. In addition, multivariate regression analysis was applied to investigate the extent to which an influence could be observed on acceleration and on jumps in acceleration at the action points. Large differences in the positions of action points in the (Δv, s) plane, acceleration, and jumps in acceleration were observed between conditions; therefore, car-following patterns closely resemble those predicted by psycho-spacing theory. However, a large degree of inter- and intradriver heterogeneity was observed, possibly caused by differences in mental workload within and between drivers. This heterogeneity indicates that the assumption of deterministic perceptual thresholds is unrealistic and necessitates the development of a data-driven stochastic model based on the principles of psycho-spacing models.

Potential Performance Costs Associated with Large-Format Tiled Displays for Surgical Visualization

Twenty-five participants performed a surgical training task on a large format display created from one projector or by tiling the images from a 4-, or 9-projector array. Utilizing a large-format display consisting of tiled projector images brings the potential benefits of increased display size with the potential threats to performance of inherent visual artifacts. The effect of these artifacts on performance and subjective workload was assessed. Results indicate that while display size did not affect performance on the surgical task, differences in mental workload were observed. Although a global measure of workload indicated that the tiled displays were the least demanding to use, participants reported deploying additional but highly specific cognitive resources when using these same displays. Their resource shifts seemed to involve adjustments to the perceived control gains created by enhanced size and also degraded ability to compare target sizes in the larger display, possibly due to the obscuring effect of tile edges.

Use of Frequency Domain Analysis of Skin Conductance for Evaluation of Mental Workload

A specially designed mental task was performed by 16 subjects for frequency domain analysis of skin conductance (SC) to evaluate mental workload. The task was to memorize target letters, detect them within a 4 x 4 alphabet arrangement, and answer whether the number of targets contained in the arrangement corresponded to a randomly displayed number. As the number of target letters increased, the score for the card-sort NASA Task Load Index (CSTLX) and task performance increased significantly. The traditional parameter for the number of transient wave forms of SC response (SCR) and the height of its wave did not show any significant effect of task difficulty. In addition, SCRs were subjected to Fourier transformation and integration of the spectrum from 0.03 to 0.5 Hz. This frequency domain analysis enabled detection of small differences in mental workload that could not be detected by traditional amplitude domain analysis. Frequency-based analysis enables easy processing of physiological signals and is very effective in evaluating mental stress using SC recorded under actual environmental conditions such as the driving of a vehicle.

Queuing Network Modeling of Age Differences in Driver Mental Workload and Performance

Modeling and predicting age differences in driver mental workload and performance may help the in-vehicle system design to reduce or prevent information overloading on older drivers. However, few computational models exist that account for age differences in mental workload. We propose a new computational modeling approach to model workload and performance–a queuing network approach based on queuing network theory of human performance (Liu, 1996, 1997) and neuroscience discoveries. This modeling approach is composed of a simulation model of a queuing network architecture and a set of mathematical equations implemented in the simulation model to quantify the age differences. The model successfully accounts for the age differences in mental workload and performance between young and older drivers in an experimental study in driving. Further usage and implementation of this model in designing adaptive in-vehicle systems to assist older drivers are discussed.

Assessment of Age Differences in Mental Workload while Driving using Verbal versus Visual-Spatial Subsidiary Tasks

Age differences in mental workload demands imposed by driving were investigated using a dual-task paradigm. Two subsidiary tasks, thought to tax separate attentional resource pools (verbal versus visual-spatial), were compared. Dual-task cost ratios [RTdual-task/RTsingle-task] using each subsidiary task were collected from young (mean age = 20.6) and older (mean age = 72.4) drivers at midblock locations (low driving task load) and while approaching intersections (high driving task load). Consistent with expectations, age differences were exacerbated on the visual-spatial subsidiary task. However, the expected workload increase at intersections (relative to midblock locations) was not observed. Instead, a more complex 3-way interaction of roadway location with subsidiary task and task order was obtained. This pattern of results has important implications with regard to the following two issues: 1) the use of discrete versus continuous subsidiary task probes during real world driving, and 2) the sensitivity and specificity of subsidiary task approaches in the assessment of age-related cognitive deficits and their potential impact upon driving performance.

A Preliminary Investigation of Individual Differences in Mental Workload: An Information Processing Based Approach

The present study examined the role of strategic processing styles in predicting both objective performance and subjective workload in a simulated ATC task across various time pressure conditions. Strategic processing styles were assessed with the Need for Cognition and Personal Need for Structure scales, the Objective Relations Test (i.e., mental rotation), and performance on the video game Tetris (i.e., spatial ability). The results revealed no significant effects of these measures on subjective workload. There were also no significant effects on error production for any of these measures, with the exception of Tetris. The results of this study are discussed within Hendy's (1994) Information-Processing model of mental workload and human performance

Dual Task Assessment of Age Differences in Mental Workload with Implications for Driving

Older drivers constitute the fastest growing segment of the driving population, in terms of both number of drivers and number of miles driven. Accident analyses reveal that older drivers are not able to fully compensate for emerging reductions in perceptual/cognitive capacity. Establishment of a method of assessing older drivers with perceptual/cognitive impairments which place them at risk of accidents is imperative. In this investigation, a subsidiary task of mental arithmetic was demonstrated to be sensitive to age differences in relative mental workload resulting from increased steering task complexity in a simulated driving task. As steering task difficulty increased, verbal response latency to concurrent mental arithmetic problems increased for older, but not younger, participants. Steering error remained stable across single and dual task conditions indicating that the secondary mental arithmetic task did not interfere with steering (primary task) performance. These results provide preliminary support for the use of this assessment technique outside of the laboratory in actual driving situations.

特集 メンタルワークロードのとらえ方 メンタルワークロードの個人差について

特集 メンタルワークロードのとらえ方 メンタルワークロードの個人差について

Effects of Physical Ability on Working Memory Requirements, Keystroke Rate, and Subjective Workload of Computer Input Devices

A reasonable assumption might be that persons with limited physical ability (persons with cerebral palsy) will experience greater mental effort in performing a physical task. Three computer input devices were used to determine if differences in physical ability result in differences in mental workload estimated by working memory capacity, keystroke rate and efficiency, and subjective workload estimated by the Task Load Index (TLX). The three devices were a voice input system, trackball, and two-degree-of-freedom keyboard with headstick. Subjects with cerebral palsy used the three devices to perform a dual-task and their results were compared with those obtained from a sample of subjects without physical disabilities. Results showed no significant difference in normalized memory capacities between the two groups. However, there were significant differences in Normalized Working Memory Capacity between devices and trials for both groups. As expected, differences in physical ability produced significant differences in keystroke rate, keystroke efficiency, and subjective workload.

The ergonomic evaluation of eye movement and mental workload in aircraft pilots

This paper presents an experiment which examines characteristics of pilots' scanning behaviour when using integrated CRT displays, and the changes in characteristics when pilots face abnormal situations. The subjects were five experienced pilots. They performed two modes of flight tasks, under normal and abnormal situations, in flight simulators with standard settings. The flight simulators were for a Boeing 747-300 (B747), which made use of electromechanical displays, and for a Boeing 767 (B767), equipped with integrated CRT displays. The results showed that the B767 pilots tended to gaze at the attitude director indicator which was displayed in the integrated CRT display. It was assumed that 'gaze-type scanning' might be one of the characteristics of pilots' scanning behaviour in cockpits which use the integrated display. By employing subjective ratings and heart rate variability to measure mental workload, no differences in mental workload between the B767 pilots and the B747 pilots were observed. However, in abnormal situations, the changes in scanning pattern for B767 pilots were found to be smaller than those of the B747 pilots. It is concluded that the application of integrated displays helps pilots to obtain sufficient information more easily than electromechanical displays do, even under abnormal situations.

Sex differences in mental workload during performance of mental tasks.

Sex differences in mental workload during performance of mental tasks.

External and internal attentional environments. II. Reconsideration of the relationship between sinus arrhythmia and information load.

As part of an investigation aimed at assessing differences in mental workload between machine-paced (MP) and self-paced (SP) work, this study focused on the relative usefulness of sinus arrhythmia (SA) and mean heart rate (MHR) as measures of informational load. Two tasks having contrasting attentional demands were performed both MP and SP by 32 subjects. Physiologically speaking, these tasks were characterized as having either cardiac deceleratory or acceleratory response patterns associated with them. An analysis of non-random trends, motivated by the presence of these response patterns, revealed the standard measure of variance, s2, to be less appropriate than the mean-square successive difference (MSSD) for scoring SA. Utilizing the MSSD, results indicated that MH R was far more sensitive than SA to the differences in informational load resulting from the intrinsic processing demands of these two tasks. SA, on the other hand, was more sensitive to the two pacing conditions. These latter findings, howe...