Multi-Attribute Task Battery Research Articles

Personality and Reaction Time after Sleep Deprivation

The relationship between reaction time and both state and trait personality variables was investigated in 37 participants after 30 h of sleep deprivation. Regression analyses suggested that endorsement of greater Novelty Seeking, anger/hostility, and depression/dejection, and less confusion, was associated with greater reaction time declines on one Multi-Attribute Task Battery index after sleep deprivation. Further, greater Novelty Seeking and depression/dejection, and less vigor/activity, was associated with greater reaction time declines after sleep deprivation on another Multi-Attribute Task Battery index. Additional correlational analyses indicated that better reaction times were associated with greater Novelty Seeking and lower anger/hostility prior to sleep deprivation, and less confusion/bewilderment following sleep deprivation. Findings suggest that both state and trait personality variables are associated with reaction time performance following sleep deprivation.

Physiological responses to workload change. A test/retest examination

The purpose of this study is to examine the test/retest consistency of physiological responses induced by mental tasks. Fifteen healthy male university students were recruited as participants. They were instructed to perform a 5-min Multi-Attribute Task Battery (MATB) trial three times successively. The task difficulty level of the tracking task of the second trial was set as medium (M). The first one was set as more difficult (H) and the last trial was easiest (L). The difficulty levels of the other two tasks (resource management and system monitoring) of the MATB were identical for all three trials. The participants repeated this procedure on three different days separated by at least a 1-day interval. The order of the tasks was the same for all repeated trials, i.e., H–M–L. Tissue blood volume from the tip of the nose using a laser Doppler blood flow meter, skin potential level (SPL), ECG from three leads on the chest, systolic time intervals (pre-ejection period, left ventricular ejection time), and hemodynamic parameters (stroke volume, cardiac output) were recorded during the task trials and before and after 5-min resting periods. The participants reported their subjective workload via NASA-TLX after each task trial. Autonomic nervous system parameters derived from the above-mentioned signals, subjective workload scores, and performance indices of MATB were analyzed, and test/retest reliability was investigated. The results showed that a significant test/retest correlation was obtained for SPL for more participants than in the other parameters, although there were large individual differences.

Effects of loratadine/montelukast on vigilance and alertness task Performance in a simulated cabin environment

Sedating effects of some medications used to treat allergic rhinitis (AR) symptoms can impair an individual's ability to function optimally. The objective of this study was to characterize the effects of a single dose of loratadine/montelukast (L/M) versus placebo and diphenhydramine on daytime somnolence and psychomotor performance in healthy volunteers. In this single-center, randomized, double-blind, placebo- and active-controlled,three-way crossover study, healthy volunteers received single doses of placebo, L/M 10 mg/10 mg, and diphenhydramine 50 mg. Subjects (n=23) were evaluated under simulated cabin pressure using the following tools: Vigilance and Tracking Task (VigTrack), measuring vigilance and tracking performance; the Multi-Attribute Task Battery (MAT), measuring ability to perform multiple tasks simultaneously; and the Stanford Sleepiness Scale (SSS), measuring sedative effects of medication, at baseline and each hour from 1 to 6 hours postdose. Safety was monitored via adverse events and vital signs. Performances on VigTrack and MAT from 1 to 6 hours after dosing were not significantly different between L/M and placebo groups; in contrast, diphenhydramine resulted in significant impairment of tracking for up to 5 hours (P< or =0.01) and vigilance performance for up to 3 hours (P< or =0.05) on VigTrack versus placebo. Scores of subjective sleepiness as measured by SSS were similar for patients treated with L/M versus placebo, whereas significant increases in sleepiness occurred between 1-5 hours posttreatment in diphenhydramine-treated patients versus placebo-treated patients (P< or =0.05). L/M is similar to placebo in effects on daytime somnolence and psychomotor performance. L/M treatment resulted in significantly less sleepiness and impairment of vigilance and tracking than diphenhydramine.

Preliminary Examination of Timesharing in United States Air Force ROTC Cadets

Previous research has shown that timesharing ability--the ability to perform multiple tasks simultaneously--is related to various indices of aircraft pilots' proficiency. Superior timesharing has also been demonstrated by experienced pilots. The present study examined timesharing of United States Air Force Reserve Officer Training Corps (AFROTC) cadets, who are relatively inexperienced (some with no flying experience). 10 AFROTC cadets (M age = 21.4 yr., SD = 1.0) and 18 noncadets (M age = 19.8 yr., SD = 0.9) were evaluated. Participants performed a tracking task on the Multi-Attribute Task battery in a single-task condition, a dual-task condition, and a tri-task condition. Cadets' tracking performance was superior to that by noncadets in the dual-task and tri-task conditions.

Mechanisms of knowledge degradation in a resource management task ¶

Previous research has focused more on learning relative to forgetting despite both being generally recognized as important human performance issues. This research pursued an improved understanding of variables that impact the effectiveness with which humans can retrieve procedural knowledge, such as mathematics or programming. Two studies reviewed yielded varying results in experiments that investigated factors that can inhibit the retrieval of procedural knowledge from memory. To explore theoretical explanations for the opposing results, 32 human participants performed a resource management task in the multi-attribute task battery (MATB) manipulating task strategy and colour symbology. Human performance resulted in significant interference effects for a switch in strategy, but not with a change in the implicit meaning of colours. Therefore, the participants’ sensitivity to the implicit meaning of visual stimuli was not as significant as a more comprehensive change in rule structure associated with procedural knowledge. This work was performed while the first and second authors were at Wright State University.

Effects of Long Audio Communication Delays on Team Performance

Mediated communication in sociotechnical systems is quite common but the effects of long audio delays remain unexplored. In the current study, two-person teams (N=67) completed a modified NASA Multi-Attribute Task Battery with closed-loop audio communication delays 0 to 16 seconds in length. In addition to a joint fuel management task, each team member had simultaneous responsibility for either a compensatory tracking or a system monitoring task. As communication delay increased, performance on the joint task degraded in a cubic fashion while individual tasks were unaffected. These results imply that audio communication delay degrades team performance in a non-linear fashion while simultaneous tasks not requiring communication are unaffected. Implications for the design of sociotechnical systems with long audio communication delays are discussed.

Performance and Psychophysiological Measures of Fatigue Effects on Aviation Related Tasks of Varying Difficulty

Fatigue is a well known stressor in aviation operations and its interaction with mental workload needs to be understood. Performance, psychophysiological, and subjective measures were collected during performance of three tasks of increasing complexity. A psychomotor vigilance task, multi-attribute task battery and an uninhabited air vehicle task were performed five times during one night's sleep loss. EEG, ECG and pupil area were recorded during task performance. Performance decrements were found at the next to last and/or last testing session. The EEG showed concomitant changes. The degree of impairment was at least partially dependent on the task being performed and the performance variable assessed.

A quantitative model of the human–machine interaction and multi-task performance: A strategy function and the unity model paradigm

A human–machine-interaction (HMI) model is developed for the human operator (HO) performing five simultaneous tasks and characterized by a strategy function. Five levels of total machine-initiated baud rate ( B IN ) are generated by the multi-attribute task battery (MATB) and five HO baud rates ( B O ) are then recorded. Total baud ratio ( B ¯ ) is defined as the ratio of B O to B IN . Results indicate that with increasing B IN levels: (1) there is an overall increase in B O , and (2) there is an overall decrease in B ¯ . These results are due to a decreasing HMI performance and divergence of the strategy function from a unity model paradigm.

Physiological Reactivity to a Multi-Task Environment

A lot of physiological parameters, mainly cardiovascular indexes, were obtained from fifteen male participants. They were asked to perform a 5-minute multi-task (MATB: Multi-Attribute Task Battery) for three times. The MATB consisted of four tasks, i. e., compensatory tracking task, system monitoring task, resource management task and communication task. The communication task was not operating in this experiment. Two participants out of fifteen showed bradycardia during the performance of MATB comparing with before and after resting periods. However, many of other participants did not show clear heart rate decreases. Therefore, above-mentioned two participants should be grouped as Vascular Reactors who show dominant Total Peripheral Resistance increment (and heart rate decrements consequently) to mental challenge rather than Cardiac Reactors who show increments in Cardiac Output. In vascular Reactors, increased vagal tone (parasympathetic nervous system activity) is elicited by mental tasks. Therefore, when we evaluate the mental workload using autonomic nervous system measures, we may be confused by the results obtained if there are Vascular Reactors, Cardiac Reactors and Mixed Reactors in participants' group at the same time.

In Search of Workload Context Effects Using a Compensatory Tracking Task

This study examined whether or not prior levels of task difficulty (context effects) impacted subsequent performance and workload ratings. Previous research by Hancock, et al. (1995) found context effects for workload ratings. Similar studies, (Fischer, 1995; Moroney et al., 1993; Rench 2002) using flight simulation tasks had not demonstrated context effects. In the current study, twelve participants completed three sessions of three compensatory tracking trials each using the Multi-Attribute Task Battery (MATB) tracking task. RMSE scores and TLX ratings were analyzed for each trial. A repeated measures design presented the first trial (Baseline) and the third trial (Critical) at a medium difficulty level. The (context inducing) middle trial had three levels of difficulty (low, medium and high). Performance and workload ratings for the baseline and critical trial were compared and showed no difficulty by trial interaction. Therefore, contrary to Hancock, et al., no context effect was obtained.

Individual Difference Effects on Performance in a Complex, Multi-Decision-Making Environment

The present research examines the impact of cognitive style and short-term memory (STM) capacity on the computer interface usability of a pilot simulation. Participants screened for individual differences in cognitive style and STM capacity were randomly assigned to a training condition within the Multi-Attribute Task Battery (MAT; Arnegard &amp; Comstock, 1991). Training conditions varied in automation settings (adaptive versus static). Participants transferred to a novel static condition. Between subjects independent variables were individual differences in STM capacity (high, low), cognitive style (analytic, holistic, quasi-rational), and training (static versus adaptive). Within subjects independent variables were training (four blocks) and transfer (four blocks) sessions. Dependent variables were accuracy and reaction time. Results suggest that individual differences in STM capacity and cognitive style are orthogonal constructs that interact to affect skill acquisition and strategy development for visual-spatial tasks. Implications related to computer interface design are discussed.

Prediction of subjective states from psychophysiology: A multivariate approach

Biocybernetic systems utilise real-time changes in psychophysiology in order to adapt aspects of computer control and functionality, e.g. adaptive automation. This approach to system design is based upon an assumption that psychophysiological variations represent implicit fluctuations in the subjective state of the operator, e.g. mood, motivation, cognitions. A study was performed to investigate the convergent validity between psychophysiological measurement and changes in the subjective status of the individual. Thirty-five participants performed a demanding version of the Multi-Attribute Task Battery (MATB) over four consecutive 20-min blocks. A range of psychophysiological data were collected (EEG, ECG, skin conductance level (SCL), EOG, respiratory rate) and correlated with changes in subjective state as measured by the Dundee Stress State Questionnaire (DSSQ). MATB performance was stable across time-on-task; psychophysiological activity exhibited expected changes due to sustained performance. The DSSQ was analysed in terms of three subjective meta-factors: Task Engagement, Distress and Worry. Multiple regression analyses revealed that psychophysiology predicted a substantial proportion of the variance for both Task Engagement and Distress but not for the Worry meta-factor. The consequences for the development of biocybernetic systems are discussed.

The influence of task demand and learning on the psychophysiological response

The level of expertise of an operator may significantly influence his/her psychophysiological response to high task demand. A naïve individual may invest considerable mental effort during performance of a difficult task and psychophysiological reactivity will be high compared to the psychophysiological response of a highly skilled operator. A study on multitasking performance was conducted to investigate the interaction between learning and task demand on psychophysiological reactivity. Thirty naïve participants performed high and low demand versions of the Multi-attribute Task Battery (MATB) over a learning period of 64 min. High and low task demand setting were preset via a pilot study. Psychophysiological variables were collected from four channels of EEG (Cz, P3, P4, Pz), ECG, EOG and respiration rate to measure the impact of task demand and learning. Several variables were sensitive to the task demand manipulation but not time-on-task, e.g., heart rate, Θ activity at parietal sites. The sensitivity of certain variables to high demand was compromised by skill acquisition, e.g., respiration rate, suppression of α activity. A sustained learning effect was observed during the high demand condition only; multiple regression analyses revealed that specific psychophysiological variables predicted learning at different stages on the learning curve. The implications for the sensitivity of psychophysiological variables are discussed.

CARDIAC CONTROL DURING DUAL-TASK PERFORMANCE OF VISUAL OR AUDITORY MONITORING WITH VISUAL-MANUAL TRACKING

Thirty university students (15 females) performed tasks from the NASA Multi-attribute Task Battery, which was used to manipulate the attentional processing resource demands of the tasks. Separate groups performed visual or auditory monitoring tasks singly and in combination with visual-manual tracking while heart period, respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) were recorded to determine the modes of cardiac control during task performance. The tracking single-task suppressed RSA and was interpreted as eliciting an uncoupled parasympathetic inhibition mode of cardiac control because of its demand upon perceptual and manual processing resources. The monitoring task both suppressed RSA and shortened PEP and was interpreted as eliciting a reciprocally-coupled sympathetic activation and parasympathetic inhibition mode of cardiac control because of its demand for perceptual/central processing resources. Dividing attention elicited uncoupled parasympathetic inhibition that was greater for the visual monitoring and tracking dual-task than for the auditory monitoring and tracking dual-task, which we interpreted as indicating a greater sharing of perceptual/spatial and manual processing resources for these tasks. Practice lengthened PEP in the dual-tasks and was interpreted as eliciting uncoupled sympathetic inhibition that was indicative of improved central processing resource efficiency. The results are evaluated in terms of how knowledge of cardiac control modes may be used to assess mental workload in applications such as adaptive automation.

Establishing the Psychophysiological Variables that can Identify &amp; Predict Operator Subjective State

Biocybernetic adaptation describes a system wherein automation is regulated by the operator's physiology. The identification of real-time psychophysiological variables capable of detecting and predicting operator subjective states is an important requisite for biocybernetic control. The present study investigated how psychophysiology may index negative subjective states, namely, task-disengagement, distress and worry. To encourage negative states, 35 participants performed the (high demand) Multi-Attribute Task Battery (MATB), for 100 minutes in total. Subjective state was assessed using the Dundee Stress State Questionnaire (DSSQ). The psychophysiological measures recorded included: GSR, EOG, EEG, ECG, and respiration. Analysis of the data revealed performance was sustained throughout the task although subjective states became more negative over time. This was accompanied by various psychophysiological changes, e.g. increased respiration rate. Regression analyses indicated that psychophysiological changes were predictive of changes in subjective states. The results and implications for biocybernetic systems are discussed.

The Effects of 37 Hours of Continuous Wakefulness On the Physiological Arousal, Cognitive Performance, Self-Reported Mood, and Simulator Flight Performance of F-117A Pilots

Pilot fatigue poses a serious threat to operational safety, but understanding the nature of the problem and the times at which pilots are most at risk will facilitate operationally relevant fatigue-management strategies. This investigation sought to address these issues in a controlled investigation of the impact of sustained wakefulness on Air Force aviators. Ten current and qualified F-117 pilots completed the Multi-At-tribute Task Battery (MATB), the Profile of Mood States (POMS), a resting eyes-open and eyes-closed EEG, and a standardized flight evaluation in an F-117 flight simulator at 5-hr intervals during the final 23 hours of a 37-hr period of continuous wakefulness. Results indicated significant decrements in mood, cognition, central nervous system activation, and flight skills began to occur in the predawn hours during a night without sleep. However, the most serious operationally relevant decrements appeared at approximately 0700 (after 25 hours without sleep) and persisted throughout the remainder of the deprivation period. The decrements suggested in the real world crew coordination likely will decline, information processing will become impaired, and a wide array of basic capabilities will be degraded as a result of compromised vigilance, poor situational awareness, and sluggish reaction time. Even the well-practiced flight skills of experienced pilots are clearly susceptible to the insidious effects of sleep loss. These quantified effects of untreated sleep deprivation will provide a baseline against which promising fatigue countermeasures can be assessed.

Real-time assessment of mental workload using psychophysiological measures and artificial neural networks.

The functional state of the human operator is critical to optimal system performance. Degraded states of operator functioning can lead to errors and overall suboptimal system performance. Accurate assessment of operator functional state is crucial to the successful implementation of an adaptive aiding system. One method of determining operators' functional state is by monitoring their physiology. In the present study, artificial neural networks using physiological signals were used to continuously monitor, in real time, the functional state of 7 participants while they performed the Multi-Attribute Task Battery with two levels of task difficulty. Six channels of brain electrical activity and eye, heart and respiration measures were evaluated on line. The accuracy of the classifier was determined to test its utility as an on-line measure of operator state. The mean classification accuracies were 85%, 82%, and 86% for the baseline, low task difficulty, and high task difficulty conditions, respectively. The high levels of accuracy suggest that these procedures can be used to provide accurate estimates of operator functional state that can be used to provide adaptive aiding. The relative contribution of each of the 43 psychophysiological features was also determined. Actual or potential applications of this research include test and evaluation and adaptive aiding implementation.

Effects of Automation Reliability on Human Monitoring Performance

Human decisions to rely on automation of a simulated flight task were monitored in the present study. Participants performed the Multi Attribute Task (MAT) battery previously developed by Comstock and Arneguard (1990). Twenty-eight participants were tested for 7 different reliability levels. Decision accuracy, false alarm rates, and reaction time to simulated automation failures were collected for each participant over nine 10-minute sessions. The results indicated that the rate of automation failures detected varied inversely with automation reliability level. As automation level increased, detection rate decreased thereby indicating automation-induced monitoring inefficiency. However, the mean reaction time of correct detection rate decreased as automation reliability level increased. No significant effect of reliability was obtained for the false alarm rate data. The implications for training and systems design are also outlined.

Effects of Information and Decision Automation on Multi-Task Performance

Automation purported to assist human operators may itself be an additional source of complexity and uncertainty. Because high reliability cannot always be assured, imperfect automation can add to uncertainty and thereby degrade performance. The present study examined the relative benefits and costs of information and decision automation and investigated the effects of uncertainty resulting from automation unreliability during multiple task performance. Subjects were either provided with status information (“information” automation) or a recommendation for action (“decision” automation) for the system monitoring sub-task of the Multi-Attribute Task Battery (MAT). Two levels of automation reliability were compared. The detrimental effect of unreliable automation—a decrease in the detection rate of malfunctions—was greater for automation of higher reliability, a result consistent with previous findings of automation-related complacency. This effect of automation unreliability was also greater for decision than for information automation.

A Closed-Loop System for Examining Psychophysiological Measures for Adaptive Task Allocation

A closed-loop system was evaluated for its efficacy in using psychophysiological indexes to moderate workload. Participants were asked to perform either 1 or 3 tasks from the Multiattribute Task Battery and complete the NASA Task Load Index after each trial. An electroencephalogram (EEG) was sampled continuously while they performed the tasks, and an EEG index (beta/alpha plus theta) was derived. The system made allocation decisions as a function of the level of operator engagement based on the value of the EEG index. The results of the study demonstrated that it was possible to moderate an operator's level of engagement through a closed-loop system driven by the operator's own EEG. In addition, the system had a significant impact on behavioral, subjective, and psychophysiological correlates of workload as task load increased. The theoretical and practical implications of these results for adaptive automation are discussed.