Michael E. McCauley

Cybersickness: perception of self-motion in virtual environments

Human perceptual systems have evolved to provide accurate information about orientation and movement through the environment. However, these systems have been challenged in the past century by modern transportation devices and will be further challenged by virtual environments (VEs) and teleoperator systems. Illusory self-motion within a VE (cyberspace) will be entertaining and instructive, but for many users it will result in motion sickness (cybersickness). Sensory conflict theory and the poison hypothesis provide an unproven theoretical foundation for understanding the phenomenon. Although no single engineering solution is likely, the problem can be contained by a combination of engineering design, equipment calibration, and exposure management.

Stress training improves performance during a stressful flight

Objective: This study investigated whether stress training introduced during the acquisition of simulator-based flight skills enhances pilot performance during subsequent stressful flight operations in an actual aircraft. Background: Despite knowledge that preconditions to aircraft accidents can be strongly influenced by pilot stress, little is known about the effectiveness of stress training and how it transfers to operational flight settings. Method: For this study, 30 participants with no flying experience were assigned at random to a stress-trained treatment group or a control group. Stress training consisted of systematic pairing of skill acquisition in a flight simulator with stress coping mechanisms in the presence of a cold pressor. Control participants received identical flight skill acquisition training but without stress training. Participants then performed a stressful flying task in a Piper Archer aircraft. Results: Stress-trained research participants flew the aircraft more smoothly, as recorded by aircraft telemetry data, and generally better, as recorded by flight instructor evaluations, than did control participants. Conclusions: Introducing stress coping mechanisms during flight training improved performance in a stressful flying task. Application: The results of this study indicate that stress training during the acquisition of flight skills may serve to enhance pilot performance in stressful operational flight and, therefore, might mitigate the contribution of pilot stress to aircraft mishaps.

Yawning as a Behavioral Marker of Mild Motion Sickness and Sopite Syndrome

INTRODUCTION Severe motion sickness is easily identifiable with sufferers showing obvious behavioral signs, including emesis (vomiting). Mild motion sickness and sopite syndrome lack such clear and objective behavioral markers. We postulate that yawning may have the potential to be used in operational settings as such a marker. This study assesses the utility of yawning as a behavioral marker for the identification of soporific effects by investigating the association between yawning and mild motion sickness/sopite syndrome in a controlled environment. METHODS Using a randomized motion-counterbalanced design, we collected yawning and motion sickness data from 39 healthy individuals (34 men and 5 women, ages 27-59 yr) in static and motion conditions. Each individual participated in two 1-h sessions. Each session consisted of six 10-min blocks. Subjects performed a multitasking battery on a head mounted display while seated on the moving platform. The occurrence and severity of symptoms were assessed with the Motion Sickness Assessment Questionnaire (MSAQ). RESULTS Yawning occurred predominantly in the motion condition. All yawners in motion (N = 5) were symptomatic. Compared to nonyawners (MSAQ indices: Total = 14.0, Sopite = 15.0), subjects who yawned in motion demonstrated increased severity of motion sickness and soporific symptoms (MSAQ indices: Total = 17.2, Sopite = 22.4), and reduced multitasking cognitive performance (Composite score: nonyawners = 1348; yawners = 1145). DISCUSSION These results provide evidence that yawning may be a viable behavioral marker to recognize the onset of soporific effects and their concomitant reduction in cognitive performance.

The Effect of Mild Motion Sickness and Sopite Syndrome on Multitasking Cognitive Performance

Objective: In this study, we investigated the effects of mild motion sickness and sopite syndrome on multitasking cognitive performance. Background: Despite knowledge on general motion sickness, little is known about the effect of motion sickness and sopite syndrome on multitasking cognitive performance. Specifically, there is a gap in existing knowledge in the gray area of mild motion sickness. Method: Fifty-one healthy individuals performed a multitasking battery. Three independent groups of participants were exposed to two experimental sessions. Two groups received motion only in the first or the second session, whereas the control group did not receive motion. Measurements of motion sickness, sopite syndrome, alertness, and performance were collected during the experiment. Results: Only during the second session, motion sickness and sopite syndrome had a significant negative association with cognitive performance. Significant performance differences between symptomatic and asymptomatic participants in the second session were identified in composite (9.43%), memory (31.7%), and arithmetic (14.7%) task scores. The results suggest that performance retention between sessions was not affected by mild motion sickness. Conclusion: Multitasking cognitive performance declined even when motion sickness and soporific symptoms were mild. The results also show an order effect. We postulate that the differential effect of session on the association between symptomatology and multitasking performance may be related to the attentional resources allocated to performing the multiple tasks. Results suggest an inverse relationship between motion sickness effects on performance and the cognitive effort focused on performing a task. Application: Even mild motion sickness has potential implications for multitasking operational performance.

Development of performance evaluation tests for environmental research (PETER): time estimation.

A time-estimation task was considered for inclusion in the Performance Evaluation Tests for Environmental Research (PETER) battery. As part of this consideration, the effects of repeated testing on the reliability of time judgments were studied. The method of production was used to estimate eight time intervals. Five trials per day at each interval were administered individually to each of 19 subjects for 15 consecutive workdays. Two scores, constant error and variable error, were reported. The effect of days was not significant for constant error and was moderate for variable error (p < .04). The standard deviations were relatively stable across trials. A pronounced decline in reliability over repeated days of testing was found for both errors. It was concluded that this time-estimation test would be a poor candidate for inclusion in PETER, but further research is warranted because of the potential unique contribution of a time-estimation task in a performance test battery.

An evaluation of the effectiveness of the crew resource management programme in naval aviation

The US Navy’s Crew Resource Management (CRM) training programme has not been evaluated within the last decade. Reactions were evaluated by analysing 51,570 responses to an item pertaining to CRM that is part of a safety climate survey. A total of 172 responses were obtained on a knowledge test. The attitudes of 553 naval aviators were assessed using an attitudes questionnaire. The CRM mishap rate from 1997 until 2007 was evaluated. It was found that naval aviators appear to think than CRM training is useful, are generally knowledgeable of, and display positive attitudes towards, the concepts addressed in the training. However, there is a lack of evidence to support the view that CRM training is having an effect on the mishap rate. As the next generation of highly automated aircraft becomes part of naval aviation, there is a need to ensure that CRM training evolves to meet this new challenge.

Sleep Duration in Rough Sea Conditions.

INTRODUCTION Environmental motion can affect shipboard sleep of crewmembers. Slamming and similar harsh motion may interfere with sleep, whereas mild motion and sopite syndrome may enhance sleep. If sleep needs vary by sea condition, this factor should be considered when assessing human performance at sea. The goal of this study was to assess sleep duration in different sea conditions. METHODS Crewmembers (N = 52) from a U.S. Navy vessel participated in the study while performing their normal daily schedule of duties. Sleep was assessed with wrist-worn actigraphy. Motion sickness and sopite syndrome were assessed using standardized questionnaires. RESULTS In rough sea conditions, crewmembers experienced increased severity of motion sickness and sopite syndrome compared to their ratings during calmer sea conditions. Crewmembers slept significantly longer during sea state 5-6 compared to sleep on days with sea state 4 (25% increase) and sea state 3-4 (30% increase). Specifically, daily sleep increased from 6.97 ± 1.24 h in sea state 3-4, to 7.23 ± 1.65 h in sea state 4, to 9.04 ± 2.90 h in sea state 5-6. DISCUSSION Although the duration of sleep in rough seas increased significantly compared to calmer sea conditions, causal factors are inconclusive. Accumulated sleep debt, motion-induced fatigue, and sopite syndrome all may have contributed, but results suggest that motion sickness and sopite syndrome were the predominant stressors. If sleep needs increase in severe motion environments, this factor should be taken into account when developing daily activity schedules or when modeling manning requirements on modern ships.

The Effect of Mild Motion Sickness and Soporific Symptoms on Multitasking Cognitive Strategy

We investigate how mild motion sickness and soporific symptoms affect cognitive strategy when performing in a multitasking environment. During two 1-hour sessions, subjects (N=39) performed four concurrent tasks (memory, arithmetic, visual, auditory). Analysis of the cognitive strategy is based on task dwell time, defined as the amount of time the screen cursor is in each task screen quadrant. Results show that the arithmetic task consistently suffers from the development of motion sickness symptoms, and increased drowsiness. Symptomatic individuals reduce the time allocated to the complex arithmetic task and increase time to the, simpler, visual task. Furthermore, symptomatic individuals demonstrate increased reaction time of correct responses in the arithmetic task, and decreased number of responses. Results provide evidence that motion sickness and soporific symptoms affect multitasking cognitive strategy with symptomatic individuals shifting focus from more complex to simpler tasks. We discuss a plausible explanation based on the performance-under-stress perspective.

Stress Training Enhances Pilot Performance During a Stressful Flying Task

This study investigated whether stress training introduced during the acquisition of simulator-based flight skills enhances pilot performance during subsequent stressful flight operations in an actual aircraft. Thirty participants with no previous flying experience were assigned either to a stress-trained treatment group or a control group. Stress training consisted of pairing skill acquisition in a flight simulator with stress coping mechanisms in the presence of a cold pressor. Control participants received identical skill acquisition training but without stress training. Performance was then compared between groups during flight in a Piper Archer aircraft. Participants who received flight simulator stress training demonstrated better performance in a stressful flying task than those in the control group. The results of this study indicate that stress training during the acquisition of flight skills may enhance pilot performance in stressful operational flight and therefore, might mitigate the contribution of pilot stress to aircraft mishaps.

Simulator sickness research program at NASA-Ames Research Center

The simulator sickness syndrome is receiving increased attention in the simulation community. NASA-Ames Research Center has initiated a program to facilitate the exchange of information on this topic among the tri-services and other interested government organizations. The program objectives are to identify priority research issues, promote efficient research strategies, serve as a repository of information, and disseminate information to simulator users.