Toward a tactile language for human-robot interaction: two studies of tacton learning and performance

OBJECTIVE

Two experiments were performed to investigate the feasibility for robot-to-human communication of a tactile language using a lexicon of standardized tactons (tactile icons) within a sentence.

BACKGROUND

Improvements in autonomous systems technology and a growing demand within military operations are spurring interest in communication via vibrotactile displays. Tactile communication may become an important element of human-robot interaction (HRI), but it requires the development of messaging capabilities approaching the communication power of the speech and visual signals used in the military.

METHOD

In Experiment 1 (N = 38), we trained participants to identify sets of directional, dynamic, and static tactons and tested performance and workload following training. In Experiment 2 (N = 76), we introduced an extended training procedure and tested participants' ability to correctly identify two-tacton phrases. We also investigated the impact of multitasking on performance and workload. Individual difference factors were assessed.

RESULTS

Experiment 1 showed that participants found dynamic and static tactons difficult to learn, but the enhanced training procedure in Experiment 2 produced competency in performance for all tacton categories. Participants in the latter study also performed well on two-tacton phrases and when multitasking. However, some deficits in performance and elevation of workload were observed. Spatial ability predicted some aspects of performance in both studies.

CONCLUSIONS

Participants may be trained to identify both single tactons and tacton phrases, demonstrating the feasibility of developing a tactile language for HRI.

APPLICATION

Tactile communication may be incorporated into multi-modal communication systems for HRI. It also has potential for human-human communication in challenging environments.

The psychometrics of mental workload: multiple measures are sensitive but divergent

OBJECTIVE

A study was run to test the sensitivity of multiple workload indices to the differing cognitive demands of four military monitoring task scenarios and to investigate relationships between indices.

BACKGROUND

Various psychophysiological indices of mental workload exhibit sensitivity to task factors. However, the psychometric properties of multiple indices, including the extent to which they intercorrelate, have not been adequately investigated.

METHOD

One hundred fifty participants performed in four task scenarios based on a simulation of unmanned ground vehicle operation. Scenarios required threat detection and/or change detection. Both single- and dual-task scenarios were used. Workload metrics for each scenario were derived from the electroencephalogram (EEG), electrocardiogram, transcranial Doppler sonography, functional near infrared, and eye tracking. Subjective workload was also assessed.

RESULTS

Several metrics showed sensitivity to the differing demands of the four scenarios. Eye fixation duration and the Task Load Index metric derived from EEG were diagnostic of single-versus dual-task performance. Several other metrics differentiated the two single tasks but were less effective in differentiating single- from dual-task performance. Psychometric analyses confirmed the reliability of individual metrics but failed to identify any general workload factor. An analysis of difference scores between low- and high-workload conditions suggested an effort factor defined by heart rate variability and frontal cortex oxygenation.

CONCLUSIONS

General workload is not well defined psychometrically, although various individual metrics may satisfy conventional criteria for workload assessment.

APPLICATION

Practitioners should exercise caution in using multiple metrics that may not correspond well, especially at the level of the individual operator.

HOSPEX in the antipodes

The Australian Army recently adopted the British concept of hospital exercise (HOSPEX) as a means of evaluating the capabilities of its deployable NATO Role 2E hospital, the 2nd General Health Battalion. The Australian approach to HOSPEX differs from the original UK model. This article describes the reasons why the Australian Army needed to adopt the HOSPEX concept, how it was adapted to suit local circumstances and how the concept may evolve to meet the needs of the wider Australian Defence Force and our allies.

The sustained attention to response task (SART) does not promote mindlessness during vigilance performance

OBJECTIVE

In this study, we evaluated the validity of the Sustained Attention to Response Task (SART) as a means for promoting mindlessness in vigilance performance.

BACKGROUND

Vigilance tasks typically require observers to respond to critical signals and to withhold responding to neutral events. The SART features the opposite response requirements, which supposedly leads it to promote a mindless, non-thoughtful approach to the vigilance task To test that notion, we compared the SART to the traditional vigilance format (TVF) in terms of diagnostic accuracy assessed through decision theory measures of positive and negative predictive power (PPP and NPP), perceived mental workload indexed by the Multiple Resource Questionnaire, and oculomotor activity reflected in the Nearest Neighbor Index and fixation dwell times.

METHOD

Observers in TVF and SART conditions monitored a video display for collision flight paths in a simulated air traffic control task.

RESULTS

Diagnostic accuracy in terms of NPP was high in both format conditions. While PPP was poorer in the SART than in the TVF, that result could be accounted for by a loss of motor control rather than a lack of mindfulness. Identical high levels of workload were generated by the TVF and SART tasks, and observers in both conditions showed similar dynamic scanning of the visual scene.

CONCLUSION

The data indicate that the SART is not an engine of mindlessness.

APPLICATION

The results challenge the widespread use of the SART to support a model in which mindlessness is considered to be the principal root of detection failures in vigilance.

Cyber Vigilance

Cyber security operators in the military and civilian sector face a lengthy repetitive work assignment with few critical signal occurrences under conditions in which they have little control over what transpires. In this sense, their task is similar to vigilance tasks that have received considerable attention from human factors specialists in regard to other operational assignments such as air traffic control, industrial process control, and medical monitoring. Accordingly, this study was designed to determine if cyber security tasks can be linked to more traditional vigilance tasks in regard to several factors known to influence vigilance performance and perceived mental workload including time on task, the probability of critical signal occurrence, and event rate (the number of stimulus events that must be monitored in order to detect critical signals). Consistent with the results obtained in traditional vigilance experiments, signal detection on a 40-minute simulated cyber security task declined significantly over time, was directly related to signal probability, and inversely related to event rate. In addition, as in traditional vigilance tasks, perceived mental workload in the cyber task, as reflected by the NASA Task Load Index, was high. The results of this study have potential meaning for designers of cyber security systems in regard to psychophysical factors that might influence task performance and the need to keep the workload of such systems from exceeding the information processing bounds of security operators.

Psychophysiological Metrics for Workload are Demand-Sensitive but Multifactorial

Various psychophysiological indices of mental workload exhibit sensitivity to task demand factors, but the psychometrics of indices has been neglected. In particular, the extent to which different metrics converge on a common latent factor is unclear. In the present study, 150 participants performed in four task scenarios based on a simulation of unmanned vehicle operation. Scenarios required threat detection and/or change detection. Both single- and dual-task scenarios were used. Workload metrics were derived from the electroencephalogram (EEG), electrocardiogram (ECG), transcranial Doppler sonography (TCD), functional Near Infra-Red (fNIR) and eyetracking. Subjective workload was also assessed. Several metrics were appropriately sensitive to the differing levels of task load presented by the four scenarios. However, factor analysis identified multiple factors, each of which was associated with a single response system only, with no general factor. Caution should be used in assessing workload in the individual operator.

Fatigue in the Automated Vehicle

As vehicle operation becomes increasingly automated, driver fatigue appears to be an increasingly pressing safety issue. Trivia games have been suggested as a fatigue countermeasure, but, like cell phone use, games may be distracting. The present study investigated whether secondary media devices impacted subjective responses and driver performance, during fatiguing drives. A manipulation of full and partial vehicle automation was used to induce fatigue during simulated driving. Participants were also assigned to one of three media device conditions (control, cell phone or trivia). Subjective state response, vehicle control and reaction time to a sudden event were recorded. The media devices did help minimize the loss of task engagement and elevated distress produced by vehicle automation. We also extended findings that the media devices helped improve concurrent driver performance. However, media usage was not associated with faster response time to subsequent events, suggesting that such devices may not lastingly enhance alertness.

Executive Functioning Protects Against Stress in UAV Simulation

Increased use of unmanned aerial vehicles (UAVs) results in a demand for suitable operators, however current selection methods may be inadequate. Transitioning to multiple UAV operation highlights attentional control ability as a criterion for selection. The current study examined the role of executive functioning (EF) in performance of a UAV simulation where high task load and evaluative stress are present. EF task performance was related more strongly to subjective stress than to performance. Specifically, high inhibitory ability may protect operators from experiencing stress processes such as worry, distress, appraisal of threat and situational uncontrollability. The findings presented add to the understanding of how EF may preserve operator’s mental well-being and protect against stress, although replication of the present findings is required.

Individual Differences in Facial Emotion Processing

This study tested whether trait emotional intelligence (TEI) measures of narrow bandwidth predict perception of facial emotion, using two tasks: identification of microexpressions of emotion and controlled visual search for target emotions. A total of 129 undergraduates completed multiple scales for TEI, as well as cognitive ability, personality, and stress measures. TEI was associated with a reduced stress response, but failed to predict performance on either task, contrary to the initial hypothesis. However, performance related significantly to higher cognitive intelligence, subjective task engagement, and use of task-focused coping. Individual differences in attentional resources may support processing of both emotive and non-emotive stimuli.

Use of EEG workload indices for diagnostic monitoring of vigilance decrement

OBJECTIVE

A study was run to test which of five electroencephalographic (EEG) indices was most diagnostic of loss of vigilance at two levels of workload.

BACKGROUND

EEG indices of alertness include conventional spectral power measures as well as indices combining measures from multiple frequency bands, such as the Task Load Index (TLI) and the Engagement Index (El). However, it is unclear which indices are optimal for early detection of loss of vigilance.

METHOD

Ninety-two participants were assigned to one of two experimental conditions, cued (lower workload) and uncued (higher workload), and then performed a 40-min visual vigilance task. Performance on this task is believed to be limited by attentional resource availability. EEG was recorded continuously. Performance, subjective state, and workload were also assessed.

RESULTS

The task showed a vigilance decrement in performance; cuing improved performance and reduced subjective workload. Lower-frequency alpha (8 to 10.9 Hz) and TLI were most sensitive to the task parameters. The magnitude of temporal change was larger for lower-frequency alpha. Surprisingly, higher TLI was associated with superior performance. Frontal theta and El were influenced by task workload only in the final period of work. Correlational data also suggested that the indices are distinct from one another.

CONCLUSIONS

Lower-frequency alpha appears to be the optimal index for monitoring vigilance on the task used here, but further work is needed to test how diagnosticity of EEG indices varies with task demands.

APPLICATION

Lower-frequency alpha may be used to diagnose loss of operator alertness on tasks requiring vigilance.

Predicting battlefield vigilance: a multivariate approach to assessment of attentional resources

Technological innovation increasingly requires operators in various applied settings to maintain vigilance for extended periods. However, standard psychometric tests typically predict less than 10% of performance variance. The present study (N = 462) aimed to apply the resource theory of sustained attention to construct a multivariate test battery for predicting battlefield vigilance. The battery included cognitive ability tests, a high-workload short vigilance task and subjective measures of stress response. Four versions of a 60- min simulated military battlefield monitoring task were constructed to represent different operational requirements. The test battery predicted 24-44% of criterion variance, depending on task version, suggesting that it may identify vigilant operators in military and other applied contexts. A multiple-groups path analysis showed that relationships between ability and vigilance were moderated by working memory demands. Findings are consistent with a diffuse theoretical concept of 'resources' in which performance energisation depends on multiple, loosely coupled processes.

Emotional intelligence and mismatching expressive and verbal messages: a contribution to detection of deception

Processing facial emotion, especially mismatches between facial and verbal messages, is believed to be important in the detection of deception. For example, emotional leakage may accompany lying. Individuals with superior emotion perception abilities may then be more adept in detecting deception by identifying mismatch between facial and verbal messages. Two personal factors that may predict such abilities are female gender and high emotional intelligence (EI). However, evidence on the role of gender and EI in detection of deception is mixed. A key issue is that the facial processing skills required to detect deception may not be the same as those required to identify facial emotion. To test this possibility, we developed a novel facial processing task, the FDT (Face Decoding Test) that requires detection of inconsistencies between facial and verbal cues to emotion. We hypothesized that gender and ability EI would be related to performance when cues were inconsistent. We also hypothesized that gender effects would be mediated by EI, because women tend to score as more emotionally intelligent on ability tests. Data were collected from 210 participants. Analyses of the FDT suggested that EI was correlated with superior face decoding in all conditions. We also confirmed the expected gender difference, the superiority of high EI individuals, and the mediation hypothesis. Also, EI was more strongly associated with facial decoding performance in women than in men, implying there may be gender differences in strategies for processing affective cues. It is concluded that integration of emotional and cognitive cues may be a core attribute of EI that contributes to the detection of deception.

Viewing the workload of vigilance through the lenses of the NASA-TLX and the MRQ

OBJECTIVE

The aim of this study was to compare the effectiveness of a new index of perceived mental workload, the Multiple Resource Questionnaire (MRQ), with the standard measure of workload used in the study of vigilance, the NASA Task Load Index (NASA-TLX).

BACKGROUND

The NASA-TLX has been used extensively to demonstrate that vigilance tasks impose a high level of workload on observers. However, this instrument does not specify the information-processing resources needed for task performance. The MRQ offers a tool to measure the workload associated with vigilance assignments in which such resources can be identified.

METHOD

Two experiments were performed in which factors known to influence task demand were varied. Included were the detection of stimulus presence or absence, detecting critical signals by means of successive-type (absolute judgment) and simultaneous-type (comparative judgment) discriminations, and operating under multitask vs. single-task conditions.

RESULTS

The MRQ paralleled the NASA-TLX in showing that vigilance tasks generally induce high levels of workload and that workload scores are greater in detecting stimulus absence than presence and in making successive as compared to simultaneous-type discriminations. Additionally, the MRQ was more effective than the NASA-TLX in reflecting higher workload in the context of multitask than in single-task conditions. The resource profiles obtained with MRQ fit well with the nature of the vigilance tasks employed, testifying to the scale's content validity.

CONCLUSION

The MRQ may be a meaningful addition to the NASA-TLX for measuring the workload of vigilance assignments.

APPLICATION

By uncovering knowledge representation associated with different tasks, the MRQ may aid in designing operational vigilance displays.

Cochlear function in patients with chronic kidney disease

OBJECTIVE

To evaluate cochlear functioning in patients (18-45 years old) with varying stages of chronic kidney disease (CKD). Using purposive sampling, 50 participants, 10 in each of the 5 stages of CKD, were selected and underwent pure tone audiometric testing and distortion product otoacoustic emissions (DPOAEs).

RESULTS

Significant differences (p < 0.05) were found between pure tone audiometry and DPOAEs in detecting early cochlear dysfunction in the high-frequency range in stages 3 (6,000/5,000 Hz; p = 0.00), 4 (6,000/5,000 Hz; p < 0.03) and 5 (4,000/3,333 Hz; p < 0.01, 8,000/6,667 Hz: p < 0.05) with DPOAEs being more sensitive in identifying early cochlear dysfunction. Patients in stages 1 and 2 presented with normal puretone thresholds and DPOAEs, suggesting that cochlear functioning in these patients was normal. Early cochlear dysfunction, thereby indicating a subclinical hearing loss, was identified in stages 3, 4 and 5 by DPOAE testing. In addition, blood test results, drug intake and concomitant conditions were recorded and analysed which suggested a relationship between reduced cochlear functioning and increased electrolyte levels, treatment regimens and concomitant conditions.

CONCLUSION

Participants in the later stages of CKD presented with early cochlear dysfunction, presenting with subclinical hearing loss. It was postulated that this subclinical hearing loss resulted from a combination of electrolytic, urea and creatinine imbalances, together with concomitant medical conditions and ototoxic drug intake. It was concluded that audiological monitoring be included in the management of patients with CKD and that DPOAEs be introduced as part of the test battery to monitor cochlear function in patients with varying degrees of CKD.

Impact of distraction on the driving performance of adolescents with and without attention-deficit/hyperactivity disorder

IMPORTANCE

This study extends the literature regarding attention-deficit/hyperactivity disorder (ADHD)-related driving impairments to a newly licensed, adolescent population.

OBJECTIVE

To investigate the combined risks of adolescence, ADHD, and distracted driving (cell phone conversation and text messaging) on driving performance.

DESIGN, SETTING, AND PARTICIPANTS

Adolescents aged 16 to 17 years with (n = 28) and without (n = 33) ADHD engaged in a simulated drive under 3 conditions (no distraction, cell phone conversation, and texting). During each condition, one unexpected event (eg, another car suddenly merging into driver's lane) was introduced.

INTERVENTIONS

Cell phone conversation, texting, and no distraction while driving.

MAIN OUTCOMES AND MEASURES

Self-report of driving history, average speed, standard deviation of speed, standard deviation of lateral position, and braking reaction time during driving simulation.

RESULTS

Adolescents with ADHD reported fewer months of driving experience and a higher proportion of driving violations than control subjects. After controlling for months of driving history, adolescents with ADHD demonstrated more variability in speed and lane position than control subjects. There were no group differences for braking reaction time. Furthermore, texting negatively impacted the driving performance of all participants as evidenced by increased variability in speed and lane position.

CONCLUSIONS

To our knowledge, this study is one of the first to investigate distracted driving in adolescents with ADHD and adds to a growing body of literature documenting that individuals with ADHD are at increased risk for negative driving outcomes. Furthermore, texting significantly impairs the driving performance of all adolescents and increases existing driving-related impairment in adolescents with ADHD, highlighting the need for education and enforcement of regulations against texting for this age group.