Heart rate and workload variations in actual and simulated flight

The monitoring of heart rate in aviation research provides a global index of pilot workload. Heart rate variability is a promising measure but more complex to assess and therefore less often used, especially in dynamic task environments. The application of spectral analysis techniques of heart rate for workload assessment in aviation is illustrated and discussed. Ideally, workload assessment includes real-time or continuous measures to reveal variations in workload as pilots accomplish their tasks. Four studies are discussed that used heart rate measures for the assessment of: (1) training effectiveness; (2) stress of flight instruction; (3) simulator realism; and (4) flight task difficulty. Results indicate that cardiovascular measures are well suited to index different mental states of pilots as well as their dynamic responses to variations in workload.     

Prediction of leadership in a simulated industrial task.

Ss high and low in dominance were selected with the CPI Dominance (Do) scale and confronted with a simulated industrial task which could be solved best by 1 person assuming a leader role and the other following his instructions. When the instructions emphasized the task, the High Do Ss did not assume the leader role significantly more often than the Low Do Ss. When leadership was emphasized, however, the High Do Ss assumed the leader role in 90% of the pairs. It is concluded that the CPI Do scale has predictive validity when leadership is made salient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control over the scheduling of simulated office work reduces the impact of workload on mental fatigue and task performance.

Two experiments tested the hypothesis that task-induced mental fatigue is moderated by control over work scheduling. Participants worked for 2 hr on simulated office work, with control manipulated by a yoking procedure. Matched participants were assigned to conditions of either high control (HC) or low control (LC). HC participants decided their own task scheduling, whereas LC participants had to follow these fixed schedules. For Experiment 1, fatigue was higher in LC participants who worked harder, so Experiment 2 compared control effects in high- and low-workload groups. As predicted, the impact of workload was reduced under HC conditions, for subjective fatigue, and most secondary tasks and aftereffects. The findings are interpreted within the framework of compensatory control theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of a cognitive-distance model to learning in a simulated travel task.

A cognitive-distance model for choice, obtained by specializing a general class of models for categorization, was tested in a situation simulating the task of controlling speed of a vehicle in tasks defined by different relations between speed and probability of delay. Subjects exhibited significant learning whenever delay schedules permitted greater-than-chance performance, but on the average they did not approach optimal performance in the sense of choosing speeds so as to maximize distance attained in allowed time. Evidence was obtained that subjects encoded information about probabilities of delay and distributions of distance attained at different speeds quite accurately in memory and that suboptimal performance was due primarily to imperfect discrimination among representations of choice alternatives on a cognitive scale of expected distance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysiological responses to changes in workload during simulated air traffic control

In this investigation, eight Air Force air traffic controllers (ATCs) performed three scenarios on TRACON (Terminal Radar Approach Control), a computer-based air traffic control (ATC) simulation. Two scenarios were used each with three levels of difficulty. One scenario varied traffic volume by manipulating the number of aircraft to be handled and the second scenario varied traffic complexity by manipulating arriving to departing flight ratios, pilot skill and mixture of aircraft types. A third scenario, overload, required subjects to handle a larger number of aircraft in a limited amount of time. The effects of the manipulations on controller workload were assessed using performance, subjective (TLX), and physiological (EEG, eye blink, heart rate, respiration, saccade) measures. Significant main effects of difficulty level were found for TRACON performance, TLX, eye blink, respiration and EEG measures. Only the EEG was associated with main effects for the type of traffic. The results provide support for the differential sensitivity of a variety of workload measures in complex tasks, underscore the importance of traffic complexity in ATC workload, and support the utility of TRACON as a tool for studies of ATC workload.     

Stimulus-response compatibility with pure and mixed mappings in a flight task environment.

The present study examined the stimulus-response compatibility (SRC) effect in a simulated flight environment. Experiments 1 and 2 tested the effect with pure and mixed mappings in flight tasks by using attitude displays with inside-out and outside-in formats, whereas Experiments 3 and 4 used a simplified display and tasks. The SRC effect was obtained with mixed mappings when responses were turns of a flight yoke (Experiments 1-3). In contrast, the SRC effect was absent with mixed mappings when they were buttonpresses (Experiment 4). Analyses of sequential effects suggest that the reduction in Experiments 1-3 can be attributed to reduction in the frequency of trials for which the congruent mapping repeats, but the elimination in Experiment 4 cannot be. Implications of the findings are discussed in the context of aviation cockpit design. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of sleep deprivation on performance in a simulated communication task.

"Twenty Ss were tested for their ability to receive and send complex instructions in a simulated communication situation following 55 and 70 hr. without sleep. The ability to receive showed a significant decrement, but the ability to send did not. The time required to send instructions and the number of errors corrected spontaneously increased significantly. In the case of sending, high-intelligence Ss showed greater decrement than low-intelligence Ss." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postnatal development under conditions of simulated weightlessness and space flight

The axial structures, the notochord and the neural tube, play an essential role in the dorsoventral patterning of somites and in the differentiation of their many cell lineages. Here, we investigated the role of the axial structures in the mediolateral patterning of the somite by using a newly identified murine homeobox gene, Nkx-3.1, as a medial somitic marker in explant in vitro assays. Nkx-3.1 is dynamically expressed during somitogenesis only in the youngest, most newly-formed somites at the caudal end of the embryo. We found that the expression of Nkx-3.1 in pre-somitic tissue explants is induced by the notochord and maintained in newly-differentiated somites by the notochord and both ventral and dorsal parts of the neural tube. We showed that Sonic hedgehog (Shh) is one of the signaling molecules that can reproduce the effect of the axial structures by exposing explants to either COS cells transfected with a Shh expression construct or to recombinant SHH. Shh could induce and maintain Nkx-3.1 expression in pre-somitic mesoderm and young somites but not in more mature, differentiated ones. The effects of Shh on Nkr-3.1 expression were antagonized by a forskolin-induced increase in the activity of cyclic AMP-dependent protein kinase A. Additionally, we confirmed that the expression of the earliest expressed murine myogenic marker, myf 5, is also regulated by the axial structures but that Shh by itself is not capable of inducing or maintaining it. We suggest that the establishment of somitic medial and lateral compartments and the early events in myogenesis are governed by a combination of positive and inhibitory signals derived from the neighboring structures, as has previously been proposed for the dorsoventral patterning of somites.     

The role of visual occlusion in altitude maintenance during simulated flight.

The use of visual occlusion as a cue to altitude maintenance in low-altitude flight (LAF) was investigated. The extent to which the ground surface is occluded by 3-D objects varies with altitude and depends on the height, radius, and density of the objects. Participants attempted to maintain a constant altitude during simulated flight over an undulating terrain with trees of various heights, radii, and densities. As would be predicted if participants used occlusion, root-mean-square error was related to the product of tree height and tree density (Experiment 1) and to the product of tree radius and tree density (Experiment 2). This relationship was also found for simulated terrains with a more realistic mixture of tree heights (Experiment 4). The authors present a modification to an occlusion model (T. Leung & J. Malik, 1997) that can be used to approximate occlusion in the context of LAF, and they evaluate the modified model using the present LAF data. On a practical level, simulating 3-D objects is computationally expensive. The present results suggest that performance may be maintained with fewer objects if their size is increased. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Utility of managerial self-planning on a simulated production task with replications in twelve countries.

A total of 1,416 managers from 12 countries completed the "Exercise Organization" simulation in 3-man teams during the course of management training workshops. After team planning on how to execute a task that simulates production and assembly, they exchanged plans with another team. Then both teams executed both plans. A counterbalanced order was used so that half of the teams executed their own plan first and half executed the other team's plan first. As expected, objective output and efficiency were significantly greater when executing own plans. Objective payoff from self-planning was greatest for North Americans and least for Germans and Danes. Significant order effects emerged. Payoff was much greater from self-planning by participants with practice than without practice. Moreover, self-planning resulted in greater felt responsibility, job satisfaction, and satisfaction with the plan. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Race and sex as determinants of ratings by potential employers in a simulated work-sampling task.

Examined the way the sex and race of the rater and the sex and race of the ratee influence assessments of ratee performance on a simulated work-sampling task. 36 undergraduates assumed the role of a manager and rated all 8 combinations of male-female and black-white performers. Results indicate that sex-race stereotypes do influence assessments of behavior on a work-sampling task even when objective measures are defined. Findings are discussed in terms of potential methods of overcoming these biases to use more effectively the work samples for selection and promotion decisions are discussed. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological and subjective measures of workload when shovelling with a conventional and two-handled ('levered') shovel

Previous studies have suggested that the two-handled (levered) shovel is advantageous over the conventional spade from a biomechanical point of view. The aim of this experiment was to determine whether less energy was consumed while shovelling a load of sand with this shovel compared to a conventional tool. Accordingly, an experiment was designed in which subjects (n = 10) shovelled 1815 kg sand under laboratory conditions using either a conventional or a levered shovel. Heart rate and oxygen consumption were measured continuously during the trial and subjective data on perceived exertion, general fatigue and body discomfort were recorded after the trial. Although total energy expenditure was similar under both conditions (120 +/- 20 and 125 +/- 25 kcal; conventional versus two-handled spade), average heart rate was 4% higher when the two-handled shovel was used (p < 0.05). In addition, the mass of sand per scoop was 4% less with the two-handled shovel (p < 0.05). In conclusion, subjects used similar energy expenditure to shovel 1815 kg sand with the conventional shovel and the two-handled tool despite lower mass of sand per scoop with the latter. This can be explained by the fact that the increased mass of the additional handle compensated for the lower mass of sand per scoop. The higher average heart rate while shovelling with the two-handled shovel can be explained by the more erect posture.     

Menstrual cycle effects on a VDT-based simulation task: cognitive indices and subjective ratings

It is unclear whether the menstrual cycle affects the basics of performance, mainly task performance and cognitive functions. We examined menstrual cycle effects on VDT-based task performance, cognitive indices based on the signal-detection theory, and subjective ratings in questionnaires. We experimented in three phases: premenstrual, menstrual and postmenstrual phases. Previous studies reported premenstrual tension syndrome (PMST) in the premenstrual phase. Women used physiological and psychological strategies to cope during the menstrual phase. However, task performance, cognitive indices and subjective ratings showed no menstrual cycle effects. Thus, we can conclude that the information processing for the VDT-based task was not affected by menstrual cycle.     

Social learning by orangutans (Pongo abelii and Pongo pygmaeus) in a simulated food-processing task

Increasing evidence for behavioral differences between populations of primates has created a resurgence of interest in examining mechanisms of information transfer between individuals. The authors examined the social transmission of information in 15 captive orangutans (Pongo abelii and Pongo pygmaeus) using a simulated food-processing task. Experimental subjects were shown 1 of 2 methods for removing a suite of defenses on an "artificial fruit." Control subjects were given no prior exposure before interacting with the fruit. Observing a model provided a functional advantage in the task, as significantly more experimental than control subjects opened the fruit. Within the experimental groups, the authors found a trend toward differences in the actual behaviors used to remove 1 of the defenses. Results support observations from the wild implying horizontal transfer of information in orangutans and show that a number of social learning processes are likely to be involved in the transfer of knowledge in this species.     

External support for collaborative problem solving in a simulated provider/patient medication scheduling task.

Taking medication requires developing plans to accomplish the activity. This planning challenges older adults because of age-related cognitive limits and inadequate collaboration with health providers. The authors investigated whether an external aid (medtable) supports collaborative planning in the context of a simulated patient/provider task in which pairs of older adults worked together to create medication schedules. Experiment 1 compared pairs who used the medtable, blank paper (unstructured aid), or no aid to create schedules varying in complexity of medication constraints (number of medications and medication co-occurrence restrictions) and patient constraints (available times during the day to take medication). Both aids increased problem-solving accuracy and efficiency (time per unit accuracy) compared to the no-aid condition, primarily for more complex schedules. However, benefits were similar for the two aids. In Experiment 2, a redesigned medtable increased problem-solving accuracy and efficiency compared to blank paper. Both aids presumably supported problem solving by providing a jointly visible workspace for developing schedules. The medtable may be more effective because it externalizes constraints (relationships between medication and patient information), so that participants can more easily organize information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The additivity of the times for human motor response elements in a simulated industrial assembly task.

The aim was an "attempt to resolve the differences and extend the applicability of the additivity concept to more complex motion patterns which might be expected to influence the interaction of the motion elements composing it." Time measurements were made in a light manual assembly task requiring 16 motion elements in the incomplete cycle for 16 male Ss. The results indicated "total incomplete cycle times predicted from data obtained in the complete cycle did not differ significantly from times actually measured even though there was evidence of interactions among the motion elements and the variables of discrimination and hands-used (one-handed versus two-handed performance)." Additivity is thus concluded to be a valid concept. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological responses to simulated rock climbing at different angles

PURPOSE: Although rock climbing has increased in popularity as a recreational activity and competitive sport, few studies have assessed the physiological demands of the activity. To describe the physiological responses to rock climbing at different angles. METHODS: Sixteen experienced climbers (age = 26 +/- 8 yr) attempted intermittent climbing bouts at different angles on a special rock climbing treadmill (Brewer's Ledge Treadwall). Heart rate (HR) was monitored continuously, and VO2 was determined at 20-s intervals during each climbing bout. Immediately after each bout, the subject provided a rating of perceived exertion (RPE), and an average of right and left handgrip force (HG) was obtained. Blood was collected via fingerprick after each bout and analyzed for lactate (BL). On a separate day, each subject completed a steady-state treadmill running bout at a HR equal to that obtained at an 86 degree angle during the climbing test. This test was followed by a progression to exhaustion to determine peak HR and VO2 responses. RESULTS: While HR increased with climbing angle, VO2 did not significantly vary. BL began to significantly increase as the angle exceeded vertical (91 degrees) and continued to increase with successive angles. HG decreased with increasing angle and was negatively correlated with BL (r = -0.96). Scores for RPE increased with steeper angles. The comparison of steady-state work at the same HR for climbing versus treadmill running revealed a higher VO2 during running with no differences in BL and RPE. CONCLUSIONS: Based upon these results, it was concluded that continuous rock climbing over terrain steepness of 80 degrees to 102 degrees presents a "very heavy" work challenge, averaging 8.4-9.0 metabolic equivalents, regardless of angle. Despite similar RPE and BL, the relative exercise intensity elicited from simulated rock climbing is lower than that of running at the same HR.     

P300 correlates of simulated malingered amnesia in a matching-to-sample task: topographic analyses of deception versus truthtelling responses

Two experiments using a P300-enhanced Forced Choice Procedure (P3FCP) investigated simulated amnesia in a matching-to-sample task. In Experiment 1, successful manipulation of subjects towards different behavioral hit rates (75-80% vs. 85-90%) did not adversely affect the diagnostic sensitivity of match-mismatch Pz-P300 amplitude analyses, allowing detection of 69% of simulators. P300 amplitudes of simulators (Malinger group) were as large as those of truth-tellers (truth group, a control), indicating no dual task-related (Malingering) reduction across different behavioral hit rates. Experiment 2 found no main effect of oddball type, match vs. mismatch, on P300 (P3) amplitude with a mismatch-rare variant of the P3FCP. This study also revealed larger Pz-P3s in the Malingering (vs. Truth-telling) condition. Subsequent topographic analyses suggested different Truth and Malinger scaled P3 amplitude topographies in both these sets of P3FCP data and in those from a previous autobiographical memory paradigm. Further analysis yielded preliminary evidence for a common deception-related P3 amplitude topography across different paradigms/conditions.     

Impact of individual differences, reward distribution, and task structure on productivity in a simulated work environment.

Analyzed the effects of intragroup competition on group productivity within a research design that accounted for both individual differences and experimental effects. 72 college students were given the Minnesota Clerical Test and then randomly assigned to 3-man groups in 1 of 4 conditions: differential- or equal-reward distribution or high- and low-task-flow interdependence. Individuals in the differential-reward and the low-task-flow-interdependence conditions were more productive than those in the equal-reward and the high-task-flow conditions. Differential and experimental analyses combined accounted for more variance in productivity than either analysis alone. Both experimental conditions moderated the relationship between the test and productivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imitative learning by captive western lowland gorillas (Gorilla gorilla gorilla) in a simulated food-processing task.

Although field studies have suggested the existence of cultural transmission of foraging techniques in primates, identification of transmission mechanisms has remained elusive. To test experimentally for evidence of imitation in the current study, the authors exposed gorillas (Gorilla gorilla gorilla) to an artificial fruit foraging task designed by A. Whiten and D. M. Custance (1996). Gorillas (n?=?6) watched a human model remove a series of 3 defenses around a fruit. Each of the defenses was removed using 1 of 2 alternative techniques. Subsequent video analysis of gorillas' behavior showed a significant tendency to copy the observed technique on 1 of the individual defenses and the direction of removal on another defense. This is the first statistically reliable evidence of imitation in gorillas. Sequence of defense removal was not replicated. The gorillas' responses were most similar to those of chimpanzees. (PsycINFO Database Record (c) 2011 APA, all rights reserved)