Psychophysiology in ergonomics. Introduction.
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Ergonomics↗
Biomedical subjects
W Boucsein
Publications and source records attributed to W Boucsein.
Social-physiological compliance as a determinant of team performance.
A cybernetic model of behavior predicts that team performance may depend on physiological compliance among participants. This laboratory study tested if compliance in electrodermal activity (EDA), heart rate or breathing in two-person teams (N=16) was predictive of team performance or coordination in a continuous tracking task simulating teleoperation. Visual contact among participants was manipulated. Physiological compliance was scored with weighted coherence and cross correlation. Separate multiple regression analyses revealed that the task completion time was predicted by coherence measures for EDA and heart, but only at a trend level for breathing. Task completion time was also predicted by heart cross correlation. Team tracking error was predicted by coherence measures for EDA, heart and breathing, and also heart cross correlation. While social-visual contact did not have an impact, physiological compliance was predictive of improved performance, with coherence robust over all three physiological measures. Heart cross correlation showed the strongest predictive relationships. These results provide evidence that physiological compliance among team members may benefit team performance. While further study is needed, physiological compliance may someday provide a needed tool for the study of team work, and an objective means to guide the ergonomic design of complex sociotechnical systems requiring a high degree of team proficiency.
Adolescent↗
Comparison of electrodermal constant voltage and constant current recording techniques using the phase angle between alternating voltage and current.
If electrodermal activity is recorded with direct current, constant voltage and constant current measurements result in different dependencies of electrodermal reactions on the actual electrodermal level. The present study demonstrates empirically that such a problem does not exist when instead the phase angle changes between alternating current and voltage are obtained. Forty subjects were subjected to a 20-trial habituation series on two different occasions, in which electrodermal level variations were induced by room temperature changes. A multiplexing system was used to enable quasi-simultaneous constant current and constant voltage recording under both direct and alternating current measurement conditions. If the alternating current technique was applied and electrodermal responses were expressed as changes of phase angle between voltage and current, electrodermal recordings with constant voltage and with constant current provided equivalent results, even if electrodermal levels were considerably different. Therefore, using the phase angle method instead of the conventional direct current methods will finally resolve the problem of differential level dependency in electrodermal recording. A further advantage will be that electrode and skin polarization are prevented by the use of alternating current.
Acoustic Stimulation↗
Effects of stimulus intensity, risetime, and duration on autonomic and behavioral responding: implications for the differentiation of orienting, startle, and defense responses.
The effects of stimulus intensity, duration, and risetime on the autonomic and behavioral components of orienting, startle, and defense responses were investigated. Six groups of 10 students were presented with 15 white noise stimuli at either 60 or 100 dB, with controlled risetimes of either 5 or 200 ms, and at stimulus durations of 1 or 5 s (1 s only in the case of the 60-dB groups). A dishabituation stimulus consisting of a 1000 Hz tone was also presented. Measures consisted of skin conductance and heart rate, together with ratings of facial expressions and upper torso movement obtained using video recording. Increased intensity resulted in greater amplitudes and frequencies of electrodermal and behavioral responses, and a change from cardiac deceleration to acceleration. Faster risetimes elicited larger electrodermal responses, greater frequencies of eye-blinks, head and body movements, and larger cardiac accelerations. The effects of duration for the 100-dB stimuli were less clear-cut. Overall, the results are discussed in relation to the differentiation of orienting, startle, and defense responses.
Acoustic Stimulation↗
Effects of different stress settings on cardiovascular parameters and their relationship to daily life blood pressure in normotensives, borderline hypertensives and hypertensives.
The aim of this study was to compare a traditional stress setting, consisting of two mental arithmetic tasks and two Stroop test modifications, and a stress setting of varying task demand and decision latitude according to Karasek's job strain model, with respect to their feasibility to elicit differences in cardiovascular reactivity and recovery in 20 normotensives, 20 borderline hypertensives, and 20 non-medicated hypertensives, carefully selected by means of World Health Organization criteria. In addition, the relationship between laboratory and everyday blood pressure was investigated. All subjects were tested under both stress settings in counterbalanced order. Blood pressure was recorded both intermittently from the brachial artery (Riva-Rocci) and continuously from the finger (Finapres). Heart rate and electrodermal activity were continuously measured as well. Furthermore, daily life blood pressure recorded by means of 24 h ambulatory monitoring during a normal working day served as criterion for the re-classification of the blood pressure groups by means of discriminant analysis using physiological recordings from baseline, test phases and rest phases. The groups did not show significant differences in their reactivity to the various mental stressors including the Karasek-model oriented ones but marked differences in their behaviour occurred during the 10 min of recovery following each stress setting. Both systolic and diastolic blood pressure in hypertensives failed to recover during this period. The results also showed the superiority of the Finapres method with respect to reflecting the dynamics of physiological recovery processes. None of the stress settings showed an advantage in predicting blood pressure in daily life. In general, the results question the validity of mental laboratory stressors for the prediction of cardiovascular changes in daily life but point to a possible role of recovery processes after stress in the development of essential hypertension.
Adult↗
Psychophysiological stress effects from the combination of night-shift work and noise.
The influence of night-shift work and noise on arousal and stress reactions have, to date, been investigated separately. The aim of this study was to compare their psychophysiological effects in combination. Twenty-four male student subjects continuously performed ten hours of visual display tasks per 24 h under highly controlled conditions for either five consecutive day or night shifts, followed by two days of rest. Each group worked in conditions of simulated traffic noise, at either 80 or 50 dB(A). Urinary catecholamines, electrodermal activity, heart rate, and ratings of mood and physical symptoms were recorded continuously or at specified intervals. Catecholamine excretion rates, autonomic reactions, reaction times, and ratings of subjective alertness showed changes typical for night-shift work. No main effects of noise were found, but significant interactions between the two experimental factors reflected differential actions of noise dependent on the type of shift. The results favor a multiple-arousal concept. Night-shift work primarily influences general arousal, while noise affects both general and goal-directed arousal, dependent on the presentation during day or night shift.
Adult↗
[Memory performance of Parkinson patients with and without sleep apnea syndrome].
We investigated the effect of SAS on the long term memory in PD patients and compared them with patients with brain infarction or cataract (control group), respectively. PD patients develop SAS and cognitive impairments more often then healthy people. Since SAS leads to a fragmentation of the sleep structure it interferes with memory. Therefore SAS may be a pathogenic factor of cognitive impairment in PD. We studied 14 patients (7 with and 7 without SAS) with PD, brain infarction or cataract using the LGT-3, which measures the verbal, numeric and figural long term memory. All patients answered subtest 7 of the Wechsler-Memory-Scale at night and in the morning. The saving between the evening and morning measure was calculated. An analysis of variance was performed using the SAS-condition and the different groups as independent variable. A significant difference (p < or = 0.005) of all memory measurements between patients with and without SAS but not between the different groups has been proved with a superiority of the patients without SAS. A significant difference of the influence of the SAS for verbal memory score on patients with PD (pp < or = 0.05) and brain infarction (pp < or = 0.005) respectively and the control group could be demonstrated. Therefore we found a quantitative difference of memory consolidation in PD patients with SAS. The influence of SAS on memory in patients with neurological disease is more pronounced compared to the control group.
Cataract↗
Standardized task strain and system response times in human-computer interaction.
Involuntary delays in human-computer interaction, for example, system response times (SRTs) can increase stress. In the present study, 40 college-age subjects were randomly divided into an 'incentive' and a 'non-incentive' group'. Subjects performed a computer task with SRTs of 0.5, 1.5, and 4.5s. Physiological, subjective, and performance data were collected during the task. The computer task was designed to individually set difficulty level (i.e., mental strain), thus standardizing the task for all subjects. By using this procedure, changes resulting from SRT duration can be separated from the effects related to task difficulty. The results indicate that both short and long SRTs produced differential psychophysiological changes consistent with different types of stress responses. Short SRTs resulted in higher autonomic and somatic activity, increased positive self-reported emotional states but poorer performance. Long SRTs resulted in increased electrodermal activity, negative self-reported emotional states and better performance.
Adult↗
Autonomic indicators of information processing related to conditioning.
The aim of the present study was to quantitatively investigate the role of information processing in conditioning using stimuli with varying amounts of information content. A letter reproduction task varying in complexity served as the unconditioned stimulus. In the first experiment, we tested the indicator function of electrodermal and cardiovascular variables. The amount of information processing resources required emerged most clearly in electrodermal reactions (EDRs), showing an increase with increasing stimulus information content. A second experiment was performed using the same design to confirm the role of processing resources allocation during conditioning by means of an independent indicator. A reaction time task was introduced as a measure of information processing resources utilized. The results paralleled the dependence of EDRs on stimulus information content, as was found in the first experiment.
Adult↗
The effects of control on stress-induced gastric erosions: the use of active shuttle-box avoidance learning with yoked controls.
The aim of the present study was to investigate effects of instrumental control on the development of stress-induced gastric erosions by using a shuttle-box paradigm with yoked controls. In Experiment 1 the learning conditions had a reinforcement ratio of only 70% to increase stress during the short-term learning session. No significant differences of the mean cumulative length of gastric erosions between active avoiding and yoked groups were found. Experiment 2 tested three different reinforcement conditions (70%, 90%, 100%) with yoked groups. Again, no significant differences of the mean cumulative length of erosions between active avoiding and yoked control groups were obtained. Instead, the length of erosions decreased with increasing reinforcement. Taken together, the data show that the frequency of unavoided noxious stimuli as a function of the reinforcement schedule can be seen as a major influence on the development of gastric erosions in a shuttle-box paradigm.
Animals↗
Adaptive versus maladaptive emotional tension.
The problem of emotional tension is usually discussed only with regard to its negative (maladaptive) aspects. The positive (adaptive) function of emotional tension, however, is as important as its negative function. In this article, we have examined psychophysiological outcomes of adaptive versus maladaptive emotional tension with respect to opposite forms of behavior (search activity and renunciation of search) that have an opposite outcome on body resistance and performance. Some traditional psychophysiological problems, for example, the law of initial values (Wilder, 1931), the difference between orienting and defensive reaction, or between anxiety and panic behavior, are revised on the basis of the assumption of adaptive and maladaptive emotional tension.
Adaptation, Psychological↗
[Effect of system-related work interruptions in computer-assisted text processing: a field study].
To validate laboratory research findings on the stress inducing effects of system response time in human-computer interaction, a field study was performed at the central typing office of a bank. Simultaneous subject-oriented and object-oriented measures (questionnaires) of working properties were taken with a relatively high sampling rate over several days in addition to the ordinary business activities. In summary, the negative effects of system response times could also be observed in the real work setting, but were modified by subjective and situational factors which had not been considered in laboratory research yet. The users also avoided situations of temporal uncertainty by adapting their working style to the system. Therefore it is concluded, that the effects of system response time should be interpreted by the concept of user acceptance and not by temporal uncertainty.
Adult↗
[Effects of waiting times within simple problems: an analogy to waiting times in human-computer interaction].
The impact of forced intra-task waiting periods was evaluated in a laboratory study designed in analogy to forced waiting periods in human-computer interaction. Each task consisted of two lines of grouped capital letters (so-called Sterzinger lines) that had to be processed individually, separated by the experimental waiting period. The final response to both lines was taken after removal of the second line. The experiment was conducted according to a within-subjects design with the order of the two factors "duration" (2 s vs. 8 s) and "variability of the waiting periods" (constant vs. variable) controlled. The dependent variables were performance indices, heart rate, electrodermal activity, and subjective measures of mood and physical complaints. The results showed effects of the duration of waiting periods for the performance and the physiological variables, and effects of the variability factor for the subjective variables. Shorter waiting periods were associated with higher scores of heart rate and skin resistance responses, variable waiting periods seemed to confuse the subjects more than constant ones. The results are discussed with respect to the effects of the two experimental factors. With respect to dialog structures in human-computer interaction, the results lead to the conclusion that response interference could be avoided by giving the user the possibility to immediately input problem solutions. Partial and preliminary inputs should be permanently kept visible during the whole task cycle by the software.
Adult↗
Continuous recordings of impedance and phase angle during electrodermal reactions and the locus of impedance change.
The relatively few studies that use alternating current (AC) in exosomatic electrodermal recording techniques focus on tonic measurement but not on phasic measures. AC methods of phasic measurement, however, are most useful in testing electrical models of the electrodermal response. Problems arising from AC recording of fast electrodermal changes are discussed, and an appropriate measurement concept for continuous recording of impedance and phase angle is developed. This enables tonic values of both parameters to be offset in order to sufficiently amplify small changes. An AC frequency of 100 Hz was used in recording electrodermal activity in 10 subjects during an habituation series of 80dB 1000 Hz tones. Comparison of transformed curves showed that the main component of electrical changes accompanying electrodermal response is a shift in conductance while susceptance shows only small fluctuations. According to a widely accepted simple electrical model of skin, these results indicate that electrodermal responses take place mainly in the resistive element which parallels the capacitance associated with the stratum corneum, but that other components may be involved too.
Adult↗
Experimental investigation of psychophysiological stress-reactions induced by different system response times in human-computer interaction.
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Adult↗
Effects of a warning signal on reactions to aversive white noise stimulation: does warning "short-circuit" habituation?
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Acoustic Stimulation↗
Dependence of skin conductance reactions and skin resistance reactions upon previous level.
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Acoustic Stimulation↗
[Psychological and physiological effects of cloxazolam and diazepam under anxiety-evoking and control conditions on healthy subjects (author's transl)].
The physical and psychophysiological effects of an orally administered single dose of 3 mg cloxazolam as compared to 5 mg diazepam and a placebo were investigated for 144 healthy male subjects using a double blind technique. In a pre-experimental test, the Ss were classified as either emotional stabiles or labiles, and in the experimental program of one four and half hour period were tested under either stress or control conditions. In order to create appropriate conditions for testing the tranquilizers, three stress situations that would induce anxiety were used: anticipation of an electric shock, preparation of a public speech and one due to failure in an achievement test. By combining these methods it was possible to sustain for 30 minutes in healthy Ss a state of anxiety or emotional activation which seemed suitable as a model for clinical anxiety. Under 5 mg diazepam rather week, but tranquilizer-typical effects were registered in both subjective and objective measures: an increase in self-confidence in emotional labiles, mood improvement, lower electrodermal responses and tranquilizer-typical EEG-pattern, but also subjective deactivating effects. The HR-increase elicited by anxiety induction was not influenced by Diazepam. Under 3 mg cloxazolam very similar effects to those under diazepam were apparent in the subjective measures; there was however, no mood improvement. Cloxazolam was judged as more strongly deactivating and fatigue inducing than diazepam. Cloxazolam was clearly different from diazepam with respect to its physiological effects, especially showing an obvious heart rate increase in the control group, which requires further investigation.
Adult↗