Effects of sensory modality and task duration on performance, workload, and stress in sustained attention

Self-control enhances vigilance performance in temporally irregular tasks: an fNIRS frontoparietal investigation

The present study investigated whether trait self-control impacted operators' behavior and associated neural resource strategies during a temporally irregular vigilance task. Functional near-infrared spectroscopy (fNIRS) readings of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (HbR) from 29 participants were recorded fromthe prefrontal and parietal cortices. Self-control was associated with better perceptual sensitivity (A') in the task with the irregular event schedule. A left-lateralized effect of HbO2 was found for temporal irregularity within the dorsomedial prefrontal cortex, in accordance with functional transcranial doppler (fTCD) studies. Self-control increased HbR (decreasing activation) at right superior parietal lobule (rSPL; supporting vigilance utilization) and right inferior parietal lobule (rIPL; supporting resource reallocation). However, only rSPL was associated with the vigilance decrement-where decreases in activation led to better perceptual sensitivity in the temporally irregular task. Additionally, short stress-state measures suggest decreases in task engagement in individuals with higher self-control in the irregular task. The authors suggest a trait-state-brain-behavior relationship for self-control during difficult vigilance tasks. Implications for the study include steps toward rectifying the resource utilization vs. allocation debate in vigilance-as well as validating HbO2 and HbR as effective constructs for predicting operators' mental resources through fNIRS.

Boring But Demanding: Using Secondary Tasks to Counter the Driver Vigilance Decrement for Partially Automated Driving

OBJECTIVE

We investigated secondary-task-based countermeasures to the vigilance decrement during a simulated partially automated driving (PAD) task, with the goal of understanding the underlying mechanism of the vigilance decrement and maintaining driver vigilance in PAD.

BACKGROUND

Partial driving automation requires a human driver to monitor the roadway, but humans are notoriously bad at monitoring tasks over long periods of time, demonstrating the vigilance decrement in such tasks. The overload explanations of the vigilance decrement predict the decrement to be worse with added secondary tasks due to increased task demands and depleted attentional resources, whereas the underload explanations predict the vigilance decrement to be alleviated with secondary tasks due to increased task engagement.

METHOD

Participants watched a driving video simulating PAD and were required to identify hazardous vehicles throughout the 45-min drive. A total of 117 participants were assigned to three different vigilance-intervention conditions including a driving-related secondary task (DR) condition, a non-driving-related secondary task (NDR) condition, and a control condition with no secondary tasks.

RESULTS

Overall, the vigilance decrement was shown over time, reflected in increased response times, reduced hazard detection rates, reduced response sensitivity, shifted response criterion, and subjective reports on task-induced stress. Compared to the DR and the control conditions, the NDR displayed a mitigated vigilance decrement.

CONCLUSION

This study provided convergent evidence for both resource depletion and disengagement as sources of the vigilance decrement.

APPLICATION

The practical implication is that infrequent and intermittent breaks using a non-driving related task may help alleviate the vigilance decrement in PAD systems.

HD-tDCS mitigates the executive vigilance decrement only under high cognitive demands

Maintaining vigilance is essential for many everyday tasks, but over time, our ability to sustain it inevitably decreases, potentially entailing severe consequences. High-definition transcranial direct current stimulation (HD-tDCS) has proven to be useful for studying and improving vigilance. This study explores if/how cognitive load affects the mitigatory effects of HD-tDCS on the vigilance decrement. Participants (N = 120) completed a modified ANTI-Vea task (single or dual load) while receiving either sham or anodal HD-tDCS over the right posterior parietal cortex (rPPC). This data was compared with data from prior studies (N = 120), where participants completed the standard ANTI-Vea task (triple load task), combined with the same HD-tDCS protocol. Against our hypotheses, both the single and dual load conditions showed a significant executive vigilance (EV) decrement, which was not affected by the application of rPPC HD-tDCS. On the contrary, the most cognitively demanding task (triple task) showed the greatest EV decrement; importantly, it was also with the triple task that a significant mitigatory effect of the HD-tDCS intervention was observed. The present study contributes to a more nuanced understanding of the specific effects of HD-tDCS on the vigilance decrement considering cognitive demands. This can ultimately contribute to reconciling heterogeneous effects observed in past research and fine-tuning its future clinical application.

Visual perceptual processing is unaffected by cognitive fatigue

Cognitive fatigue (CF) can lead to an increase in the latency of simple reaction time, although the processes involved in this delay are unknown. One potential explanation is that a longer time may be required for sensory processing of relevant stimuli. To investigate this possibility, the current study used a visual inspection time task to measure perceptual processing speed before and after a CF (math and memory) or non-fatiguing (documentary film) intervention. Subjective fatigue and simple reaction time significantly increased following the CF, but not the non-fatiguing intervention, confirming that CF was induced. Conversely, there was no effect of CF on inspection time task performance. It was therefore concluded that the speed of perceptual processing is not significantly impacted by CF, and thus is unlikely to underlie CF-related reaction time increases. Instead, increases in simple reaction time latency in CF may be due to delays in response preparation or initiation.

Modality Changes in Vigilance Displays: Further Evidence of Supramodal Resource Depletion in Vigilance

OBJECTIVE

This study was designed to evaluate the effects of a modality change on vigilance performance to determine whether depletion of modality-specific resources contributes to the vigilance decrement.

BACKGROUND

Resource theory accounts for the vigilance decrement by arguing that the demands of vigilance deplete limited information processing resources. Research indicates that both supramodal and modality-specific resources are involved in vigilance, but it is unclear whether the vigilance decrement is due to depletion of supramodal resources, modality-specific resources, or both. If depletion of modality-specific resources contributes to the decrement, changing the modality of a vigilance display should improve vigilance performance after a decrement.

METHOD

Participants completed a 50-min vigilance task beginning in either the visual modality or the auditory modality. After 40-min, half of the participants experienced a sudden transition to the other modality; the remaining participants did not experience a modality change.

RESULTS

Performance declined over time and was generally superior in the auditory modality. Changing modality from visual to auditory increased correct detections, whereas changing from auditory to visual decreased correct detections. Both types of modality change were associated with an increase in false alarms, and neither had an effect on workload or stress.

CONCLUSION

Supramodal resource depletion, rather than modality-specific resource depletion, is the most likely explanation for the vigilance decrement that can be derived from resource theory.

APPLICATION

Modality changes are not likely to counteract the vigilance decrement and may actually increase false alarm errors. Countermeasure development should involve identification of depleted supramodal resources.

An Attentional Bias Modification Task, through Virtual Reality and Eye-Tracking Technologies, to Enhance the Treatment of Anorexia Nervosa

Mirror exposure therapies (METs) have been shown to be effective in reducing body image disturbances through the habituation process. Virtual reality (VR) combined with eye-tracking techniques can provide innovative solutions to some of METs’ limitations reported with patients with anorexia nervosa (AN), especially the negative influence of body-related attentional bias (AB). This pilot study aimed to assess the preliminary efficacy of a new VR-based AB modification task (ABMT) among healthy women and the procedure’s user experience. AB levels towards weight- and non-weight-related body parts, using complete fixation time (CFT) and number of fixations (NF), were assessed throughout the ABMT procedure (300 trials). The user experience was evaluated at the end of the procedure. The results showed that VR-based ABMT was effective in reducing AB significantly after 150 trials for both CFT- and NF-based measures, although 225 trials were necessary to get the same result for women with an NF initially more oriented towards weight-related body parts. Overall, the software received a “C-rating” on a scale from “A” (most usable) to “F” (least usable). These results provide evidence of the opportunity to use a VR-based ABMT procedure to reduce AB and improve existing treatments for AN.

A multimodal approach for the ecological investigation of sustained attention: A pilot study

Natural fluctuations in sustained attention can lead to attentional failures in everyday tasks and even dangerous incidences. These fluctuations depend on personal factors, as well as task characteristics. So far, our understanding of sustained attention is partly due to the common usage of laboratory setups and tasks, and the complex interplay between behavior and brain activity. The focus of the current study was thus to test the feasibility of applying a single-channel wireless EEG to monitor patterns of sustained attention during a set of ecological tasks. An EEG marker of attention (BEI—Brain Engagement Index) was continuously recorded from 42 healthy volunteers during auditory and visual tasks from the Test of Everyday Attention (TEA) and Trail Making Test (TMT). We found a descending pattern of both performance and BEI in the auditory tasks as task complexity increases, while the increase in performance and decrease in BEI on the visual task. In addition, patterns of BEI in the complex tasks were used to detect outliers and the optimal range of attention through exploratory models. The current study supports the feasibility of combined electrophysiological and neurocognitive investigation of sustained attention in ecological tasks yielding unique insights on patterns of sustained attention as a function of task modality and task complexity.

Effects of Auditory Pre-Stimulation on Cognitive Task Performance in a Noisy Environment

The accident rate due to human errors in industrial fields has been consistently high over the past few decades, and noise has been emerging as one of the main causes of human errors. In recent years, auditory pre-stimulation has been considered as a means of preventing human errors by improving workers’ cognitive task performance. However, most previous studies demonstrated the effectiveness of the auditory pre-stimulation in a quiet environment. Accordingly, studies on the effects of pre-stimulation in a noisy environment are still lacking. Therefore, this study aimed to empirically investigate: (1) the effects of noisy environments on the performances of cognitive tasks related to different functions of working memory and (2) the effects of auditory pre-stimulation on the performances of cognitive tasks in a field-noise environment. To accomplish these research objectives, two major experiments were conducted. In the first experiment, a total of 24 participants performed each of three basic short-term/working memory (STM/WM) tasks under two different experimental conditions (quiet-noise environment and field-noise environment) depending on the presence or absence of field noise. In the second experiment, the participants performed each of the three basic STM/WM tasks in a field-noise environment after they were provided with one of four different auditory pre-stimulations (quiet noise, white noise, field noise, and mixed (white and field) noise). The three STM/WM tasks were the Corsi block-tapping, Digit span, and 3-back tasks, corresponding to the visuospatial sketchpad, the phonological loop, and the central executive of WM, respectively. The major findings were that: (1) the field-noise environment did not affect the scores of the Corsi block-tapping and 3-back tasks, significantly affecting only the Digit span task score (decreased by 15.2%, p < 0.01); and (2) the Digit span task performance in the field-noise environment was improved by 17.9% (p < 0.05) when mixed noise was provided as a type of auditory pre-stimulation. These findings may be useful for the work-space designs that prevent/minimize human errors and industrial accidents by improving the cognitive task performance of workers in field-noise environments.

Tactile Vigilance Is Stressful and Demanding

OBJECTIVE

The primary aims of the study were to replicate the vigilance decrement in the tactile modality, examine whether a decrease in sensitivity is associated with the decrement, and determine whether tactile vigilance is stressful and demanding.

BACKGROUND

When people monitor occasional and unpredictable signals for sustained durations, they experience a decline in performance known as the vigilance decrement, which has important practical consequences. Prior studies of the vigilance decrement focused primarily on visual vigilance and, to a lesser degree, on auditory vigilance. There are relatively few studies of tactile vigilance.

METHOD

Participants monitored vibrotactile stimuli that were created from a tactor, for 40 min.

RESULTS

Sensitivity declined, self-report ratings of distress increased, and ratings of task engagement decreased, during the vigil, and perceived workload was moderately high.

CONCLUSION

Monitoring tactile signals is demanding and stressful and results in a decrement in signal detection.

APPLICATION

Monitoring tactile signals may result in a decrement in tasks requiring discrimination, such as monitoring lane position with the use of rumble strips; these require discrimination between current road vibration and increased vibration when the car drifts out of its lane and crosses over the strip.

Auditory spatial attention gradients and cognitive control as a function of vigilance

Selection and effort are central to attention, yet it is unclear whether they draw on a common pool of cognitive resources, and if so, whether there are differences for early versus later stages of cognitive processing. This study assessed effort by quantifying the vigilance decrement, and spatial processing at early and later stages as a function of time-on-task. Participants performed an auditory spatial attention task, with occasional "catch" trials requiring no response. Psychophysiological measures included bilateral cerebral blood flow (transcranial Doppler), pupil dilation, and blink rate. The shape of attention gradients using reaction time indexed early processing, and did not significantly vary over time. Later stimulus-response conflict was comparable over time, except for a reduction to left hemispace stimuli. Target and catch trial accuracy decreased with time, with a more abrupt decrease for catch versus target trials. Diffusion decision modeling found progressive decreases in information accumulation rate and non-decision time, and the adoption of more liberal response criteria. Cerebral blood flow increased from baseline and then decreased over time, particularly in the left hemisphere. Blink rate steadily increased over time, while pupil dilation increased only at the beginning and then returned towards baseline. The findings suggest dissociations between resources for selectivity and effort. Measures of high subjective effort and temporal declines in catch trial accuracy and cerebral blood flow velocity suggest a standard vigilance decrement was evident in parallel with preserved selection. Different attentional systems and classes of computations that may account for dissociations between selectivity versus effort are discussed.

Joint effect of defocus blur and spatial attention

Defocus blur and spatial attention both act on our ability to see clearly over time. However, it is currently unknown how these two factors interact because studies on spatial resolution only focused on the separate effects of attention and defocus blurs. In this study, eleven participants performed a resolution acuity task along the diagonal 135˚/315˚ with horizontal, at 8˚ eccentricity for clear and blurred Landolt C images under various manipulations of covert endogenous attention. All the conditions were interleaved and viewed binocularly on a visual display. We observed that attention not just improves the resolution of clear stimuli, but also modulates the resolution of defocused stimuli for compensating the loss of resolution caused by retinal blur. Our results show, however, that as the degree of attention decreases, the differences between clear and blurred images largely diminish, thus limiting the benefit of an image quality enhancement. It also appeared that attention tends to enhance the resolution of clear targets more than blurred targets, suggesting potential variations in the gain of vision correction with the level of attention. This demonstrates that the interaction between spatial attention and defocus blur can play a role in the way we see things. In view of these findings, the development of adaptive interventions, which adjust the eye's defocus to attention, may hold promise.

Common principles underlie the fluctuation of auditory and visual sustained attention

Sustained attention plays an important role in adaptive behaviours in everyday activities. As previous studies have mostly focused on vision, and attentional resources have been thought to be specific to sensory modalities, it is still unclear how mechanisms of attentional fluctuations overlap between visual and auditory modalities. To reduce the effects of sudden stimulus onsets, we developed a new gradual-onset continuous performance task (gradCPT) in the auditory domain and compared dynamic fluctuation of sustained attention in vision and audition. In the auditory gradCPT, participants were instructed to listen to a stream of narrations and judge the gender of each narration. In the visual gradCPT, they were asked to observe a stream of scenery images and indicate whether the scene was a city or mountain. Our within-individual comparison revealed that auditory and visual attention are similar in terms of the false alarm rate and dynamic properties including fluctuation frequency. Absolute timescales of the fluctuation in the two modalities were comparable, notwithstanding the difference in stimulus onset asynchrony. The results suggest that fluctuations of visual and auditory attention are underpinned by common principles and support models with a more central, modality-general controller.

Sitting with it: An investigation of the relationship between trait mindfulness and sustained attention

BACKGROUND

Sustaining attention for extended periods of time is associated with negative affect and this increase in negative affect is related to poorer task performance. Trait mindfulness has been shown to be associated with better sustained attention performance. This may be because trait mindfulness is associated with better attention ability or better emotion regulation ability.

AIMS

The present research aims to replicate previous findings and better understand why trait mindfulness is associated with better sustained attention performance.

METHOD

Participants responded to self-report questionnaires assessing their trait mindfulness, attentional control, and experiential avoidance. Next, participants performed a sustained attention task, during which they also reported their subjective feelings of discomfort and boredom. Finally, participants reported their retrospective discomfort and boredom after the task.

RESULTS

We replicated and extended previous findings by showing that the relationship between trait mindfulness and sustained attention performance was mediated by negative affect experienced during the task. Moreover, the correlation between trait mindfulness and sustained attention disappeared when controlling for experiential avoidance, but remined when controlling for attention control.

CONCLUSION

Our results suggest that trait mindfulness is associated with sustained attention because of enhanced emotion regulation and that enhancing affective regulation would be an effective strategy for improving sustained attention performance.

The metronome response task for measuring mind wandering: Replication attempt and extension of three studies by Seli et al

Science requires replicable tools to measure its intended constructs. Attention research has developed tools that have been used in mind-wandering research, but mind-wandering measures often rely on response-inhibition, which introduces speed-accuracy trade-offs that may conflate errors for mind-wandering. We sought to replicate three studies that used an improved mind-wandering measure: the Metronome Response Task (MRT). In a large (N=300) multisite sample, the primary MRT finding was replicated, showing that continuous rhythmic response time variability reliably predicted self-reported mind-wandering. Our findings also show previously undetected differences between intentional and unintentional mind-wandering. While previously reported mediators (motivation) and moderators (confidence) did not replicate, additional covariates add predictive value and additional constructs (e.g., boredom, effort) demonstrate convergent validity. The MRT is useful for inducing and measuring mind-wandering and provides an especially replicable tool. The MRT's measurement of attention could support future models of the complete cycle of sustained attention.

Understanding individualistic response patterns when assessing expert operators on nuclear power plant control tasks

We evaluated the performance of three highly practiced participants on three task types that comprised a simulated nuclear power plant control operation. Multiple subjective, physiological, and objective performance measures were collected on these three highly-practiced individuals. Results indicated ceiling effects in terms of performance accuracy, yet each individual adopted a unique response strategy across the respective sub-tasks. Their maximised accuracy was achieved at the expense of longer response times across differing sub-tasks. The measures which proved diagnostic and predictive of performance capacity were explored. The current conclusion presents us with an invidious problem in that performance and workload associations, insensitivities, and dissociations may be unique to each individual operator, and may well depend also upon the overall task in context. Such findings push our science away from seeking nomothetic assertions and toward individuated concerns. In consequence, the age of the idiographic may well be upon us. Practitioner summary: The importance and relevance of nuclear power control is self-evident. Concerns here have centred around the safety of the technology and its operators. Our work informs practitioners in this industry, and in Ergonomics in general, of the response of highly trained individuals in these safety-critical, operational domains. We show that even experts engage in personal and individual strategies, an observation critical to the assessment of this specific workplace, and potentially all others. Abbreviations: NPP: nuclear power plant; ROs: reactor operators; MCR: main control room; LOA: levels of automation; EOP: emergency operating procedure; OP: operating procedures; ISA: instantaneous self-assessment; DSSQ: Dundee stres state questionnaire.

Stress Linked to Reports of Simulator Sickness in Vigilance: A Factor Analysis of the SSSQ and the SSQ

The current study investigated the relationship between stress and simulator sickness within vigilance tasks. The Simulator Sickness Questionnaire and the Short Stress State Questionnaire were employed. Data were aggregated from seven different visual vigilance tasks. Correlational relationships were investigated using an exploratory factor analysis, which revealed two factors. The first factor was represented by Distress, a stress measure, and all three simulator sickness subscales: Nausea, Disorientation, and Oculomotor symptoms. The second factor consisted only of Worry, a stress measure. These results suggest that the distress associated with vigilance is intertwined with reports of simulator sickness. One possible explanation is that the stress of vigilance effectively inflates reports of simulator sickness, a potential concern for the validity of simulator sickness assessments within tasks that require vigilance.

Minilaparoscopic Total Hysterectomy in Current Practice Feasibility and Benefits: A Unicentric, Randomized Controlled Trial

STUDY OBJECTIVE

To investigate whether mini-instrumentation may be used for hysterectomy (HT) by all surgeons (assistants and seniors) without increasing the operative time or altering surgeon working conditions.

DESIGN

A unicenter, randomized controlled, single blind, parallel, noninferiority trial comparing 2 surgical techniques.

SETTING

A tertiary referral center.

PATIENTS

Thirty-two patients undergoing HT for a benign gynecologic disease were enrolled in this study in our center between April 2, 2015, and June 1, 2018. Sixteen patients were randomized in group A and 16 patients in group B.

INTERVENTIONS

HT with bilateral annexectomy or ovarian conservation using 3-mm instruments (group A) or conventional 5-mm instruments (group B).

MEASUREMENTS AND MAIN RESULTS

Concerning the primary outcome, the operative time for the HT 3-mm group was 128 minutes (range, 122-150 minutes) versus 111 minutes (range, 92-143 minutes) for the HT 5-mm group (i.e., δ = 17 [90% confidence interval, -6 to 39]), with rejection of the noninferiority threshold at 35 minutes. Thirty-one percent of HTs initially performed using 3-mm instruments were completed with conventional instruments. HTs performed with mini-instruments required more concentration (p = .02) with surgeons reporting higher levels of frustration (p = .009) and sense of failure (p = .006). Patients tend to experience greater satisfaction regarding scars with a significant difference noted during the postoperative visit both for scar pain (1 vs 4 patients with moderate pain [30-50 mm on the Patient Scar Assessment Scale) in the HT 3-mm group and the HT 5-mm group, respectively) and scar firmness (p = .021; 3 vs 7 patients with moderate firmness [30-50 mm on the Patient Scar Assessment Scale] in the HT 3-mm group and the HT 5-mm group, respectively).

CONCLUSION

Total minilaparoscopic HT appears inferior to standard laparoscopy in terms of operative time and surgeon working conditions; only the short-term cosmetic appearance was in favor of the 3-mm approach.

The Effects of Event Rate on a Cognitive Vigilance Task

OBJECTIVE

The present experiment sought to examine the effects of event rate on a cognitive vigilance task.

BACKGROUND

Vigilance, or the ability to sustain attention, is an integral component of human factors research. Vigilance task difficulty has previously been manipulated through increasing event rate. However, most research in this paradigm has utilized a sensory-based task, whereas little work has focused on these effects in relation to a cognitive-based task.

METHOD

In sum, 84 participants completed a cognitive vigilance task that contained either 24 events per minute (low event rate condition) or 40 events per minute (high event rate condition). Performance was measured through the proportion of hits, false alarms, mean response time, and signal detection analyses (i.e., sensitivity and response bias). Additionally, measures of perceived workload and stress were collected.

RESULTS

The results indicated that event rate significantly affected performance, such that participants who completed the low event rate task achieved significantly better performance in terms of correction detections and false alarms. Furthermore, the cognitive vigil utilized in the present study produced performance decrements comparable to traditional sensory vigilance tasks.

CONCLUSION

Event rate affects cognitive vigilance tasks in a similar manner as traditional sensory vigilance tasks, such that a direct relation between performance and level of event rate was established.

APPLICATION

Cognitive researchers wishing to manipulate task difficulty in their experiments may use event rate presentation as one avenue to achieve this result.

Sustained Attention to Science: A Tribute to the Life and Scholarship of Joel Warm

OBJECTIVE

To provide an evaluative synthesis of the life and scientific contributions of the late Joel Warm.

BACKGROUND

As the doyen of vigilance research, Joel Warm expanded our understanding and horizons concerning this critical response capacity. However, he also made widespread and profound contributions to many other areas of perception and applied psychology, as we elucidate here.

METHOD

Using archival sources, personal histories, and analysis of extant literature documenting Warm's own productivity, we articulate his life in science.

RESULTS

Our synthesis illustrates the continued, broad, influential, and expanding impact that one individual can exert on diverse fields of study. Whole bodies of understanding of human behavior have been illuminated by his exemplary career.

APPLICATION

By understanding his path to success in applied experimental psychology, we anticipate that others will be motivated, inspired, and guided to replicate and even outstrip a lifetime of such seminal and influential contributions. The presence of individuals such as Warm serves as a primary motive in enhancing Humans Factors/Ergonomics Science.

Is Semantic Vigilance Impaired by Narrative Memory Demands? Theory and Applications

OBJECTIVE

Two verbal tasks were utilized in a dual-task paradigm to explore performance theories and prior dual-tasking results.

BACKGROUND

Both the decline in vigilance performance over time, or vigilance decrement, and limited dual-tasking ability may be explained by limited mental resources. Resource theorists would recommend removing task demands to avoid cognitive overload, while mindlessness theorists may recommend adding engaging task demands to prevent boredom. Prior research demonstrated interference between a verbal free recall and semantic vigilance task, but exploring tasks with greater ecological validity is necessary.

METHOD

A narrative memory task and semantic vigilance task were performed individually and simultaneously. Relative performance impairments were compared to a previous dual-task pairing.

RESULTS

The semantic vigilance task caused performance degradation to the narrative memory task and vice versa. A vigilance decrement was not observed, and the interference was to a lesser extent than when the semantic vigilance task was paired with a free recall task.

CONCLUSION

Resource theory was supported, though passive learning effects during a semantic vigilance task with novel stimuli may prevent a vigilance decrement. The interference was less than that of a previous similar dual-task pairing, but even tasks as routine as listening to a conversation or story can impair other task performance.

APPLICATION

A better understanding of resource theory and dual-task performance outcomes can help inform feasible task loads and improve efficiency and safety of operators in high-risk and other professions.

Individual differences in sustained attention are associated with cortical thickness

Several studies have examined how individual differences in sustained attention relate to functional brain measures (e.g., functional connectivity), but far fewer studies relate sustained attention ability, or cognition in general, to individual differences in cortical structure. Functional magnetic resonance imaging meta-analyses and patient work have highlighted that frontoparietal regions, lateralized to the right hemisphere, are critical for sustained attention, though recent work implicates a broader expanse of brain regions. The current study sought to determine if and where variation in cortical thickness is significantly associated with sustained attention performance. Sustained attention was measured using the gradual onset continuous performance task and the Test of Variables of Attention in 125 adult Veteran participants after acquiring two high-resolution structural MRI scans. Whole-brain vertex-wise analyses of the cortex demonstrated that better sustained attention was associated with increased thickness in visual, somatomotor, frontal, and parietal cortices, especially in the right hemisphere. Network-based analyses revealed relationships between sustained attention and cortical thickness in the dorsal attention, ventral attention, somatomotor, and visual networks. These results indicate cortical thickness in multiple regions and networks is associated with sustained attention, and add to the growing knowledge of how structural MRI can help explain individual differences in cognition.

Vigilance Tasks: Unpleasant, Mentally Demanding, and Stressful Even When Time Flies

OBJECTIVE

To determine whether perceived time progression (PTP) moderates participants' negative reactions to vigilance tasks.

BACKGROUND

Vigilance tasks are rated by participants to be unenjoyable and as having high levels of workload and stress. Based on the adage, "You are having fun when time flies," we tested the possibility that accelerating PTP might reduce these negative experiences.

METHOD

Two studies were performed, involving a long 30-min and a short 12-min vigil. We manipulated participants' PTP by creating a mismatch between their expectations about how long they would perform the task and the actual time that they were engaged.

RESULTS

PTP was significantly faster for participants who were led to expect that the vigilance task would last longer than it did relative to those led to expect that task duration would be shorter than it actually was and for controls for whom task duration was equal to the expected duration. However, accelerating PTP had no effect in either experiment on undesirable reactions to the vigilance tasks. Participants uniformly rated both tasks as unenjoyable, as having a high level of workload, and as stressful. Apparently, vigilance isn't fun even when time flies.

CONCLUSION

Our findings greatly underscore the depth to which negative subjective reactions are embedded in the nature of vigilance tasks and therefore that these tasks can have potentially serious costs to participants in terms of health, safety, and productivity.

APPLICATION

These costs must be considered at the operational level.

Training for vigilance on the move: a video game-based paradigm for sustained attention

The capacity for superior vigilance can be trained by using knowledge of results (KR). Our present experiments demonstrate the efficacy of such training using a first-person perspective movement videogame-based platform in samples of students and Soldiers. Effectiveness was assessed by manipulating KR during a training phase and withdrawing it in a subsequent transfer phase. Relative to a no KR control condition, KR systematically improved performance for both Soldiers and students. These results build upon our previous findings that demonstrated that a video game-based platform can be used to create a movement-centred sustained attention task with important elements of traditional vigilance. The results indicate that KR effects in sustained attention extend to a first person perspective movement based paradigm, and that these effects occur in professional military as well as a more general population. Such sustained attention training can save lives and the present findings demonstrate one particular avenue to achieve this goal. Practitioner Summary: Sustained attention can be trained by means of knowledge of results using a videogame-based platform with samples of students and Soldiers. Four experiments demonstrate that a dynamic, first-person perspective video game environment can serve to support effective sustained attention training in professional military as well as a more general population.

Examining social facilitation in vigilance: a hit and a miss

Vigilance is the ability of an observer to maintain attention for extended periods of time; however, performance tends to decline with time on watch, a pattern referred to as the vigilance decrement. Previous research has focused on factors that attenuate the decrement; however, one factor rarely studied is the effect of social facilitation. The purpose for the present investigation was to determine how different types of social presence affected the performance, workload and stress of vigilance. It was hypothesised that the presence of a supervisory figure would increase overall performance, but may occur at the cost of increased workload and stress. Results indicated that the per cent of false alarm and response times decreased in the presence of a supervisory figure. Using social facilitation in vigilance tasks may thus have positive, as well as, negative effects depending on the dependent measure of interest and the role of the observer. Practitioner Summary: Social facilitation has rarely been examined in the context of vigilance, even though it may improve performance. Vigilance task performance was examined under social presence. The results of the present study indicated that false alarms and response times decreased in the social presence of a supervisory figure, thus improving performance.

Analysts issuing forecasts on weekends

Purpose

This study aims to investigate the motivation of financial analysts issuing forecasts on weekends and the impact of such behavior on forecast accuracy and analysts’ careers.

Design/methodology/approach

Logistic regression and ordinary least squares models with Huber–White standard errors were used in this study.

Findings

This paper first documented the emerging trends of the weekend forecasts after 2000. Longitudinal data from 2002 to 2011 validated that analysts’ conscientious timing of information release in line with their workload and confidence level gives more accurate forecasts. Further, given the same accuracy, analysts exhibiting diffident behaviors (analysts who are predicted to work on weekdays but in fact work on weekends) are not fired or demoted by brokerage houses, but those exhibiting inactive behaviors (analysts who are predicted to work on weekends but did not do so) are more likely to be dismissed or demoted by brokerage houses, indicating that brokerage houses are aware of the negative effect of both behaviors, but treat them differently.

Research limitations/implications

Weekend versus weekday proxies for an analyst’s timing of information release consider only one of many timing options. Other timing proxies, the nature and the composition of the information release of analysts are not examined in this study.

Practical implications

For practitioners, the results indicate that depending on the alignment, capital market can predict analysts’ future forecast accuracy, and hence, respond accordingly. For example, in addition to analyst forecast level or change, investors could pay attention to when the information is released to the market and possible reasons behind the choice of timing. Investors can thus better assess the forecast accuracy of one specific forecast and respond with the right action. Furthermore, analysts can better project their own forecast accuracy and career potential by assessing to what extent their forecasts are released conscientiously.

Social implications

This study examines analysts’ forecast behavior, but generate some insights on linking the analysts and investors in the capital market.

Originality/value

This study is the author’s original work.

Effects of platooning on signal-detection performance, workload, and stress: A driving simulator study

Platooning, whereby automated vehicles travel closely together in a group, is attractive in terms of safety and efficiency. However, concerns exist about the psychological state of the platooning driver, who is exempted from direct control, yet remains responsible for monitoring the outside environment to detect potential threats. By means of a driving simulator experiment, we investigated the effects on recorded and self-reported measures of workload and stress for three task-instruction conditions: (1) No Task, in which participants had to monitor the road, (2) Voluntary Task, in which participants could do whatever they wanted, and (3) Detection Task, in which participants had to detect red cars. Twenty-two participants performed three 40-min runs in a constant-speed platoon, one condition per run in counterbalanced order. Contrary to some classic literature suggesting that humans are poor monitors, in the Detection Task condition participants attained a high mean detection rate (94.7%) and a low mean false alarm rate (0.8%). Results of the Dundee Stress State Questionnaire indicated that automated platooning was less distressing in the Voluntary Task than in the Detection Task and No Task conditions. In terms of heart rate variability, the Voluntary Task condition yielded a lower power in the low-frequency range relative to the high-frequency range (LF/HF ratio) than the Detection Task condition. Moreover, a strong time-on-task effect was found, whereby the mean heart rate dropped from the first to the third run. In conclusion, participants are able to remain attentive for a prolonged platooning drive, and the type of monitoring task has effects on the driver's psychological state.

Reaction Times to Consecutive Automation Failures: A Function of Working Memory and Sustained Attention

OBJECTIVE

This study explored whether working memory and sustained attention influence cognitive lock-up, which is a delay in the response to consecutive automation failures.

BACKGROUND

Previous research has demonstrated that the information that automation provides about failures and the time pressure that is associated with a task influence cognitive lock-up. Previous research has also demonstrated considerable variability in cognitive lock-up between participants. This is why individual differences might influence cognitive lock-up. The present study tested whether working memory-including flexibility in executive functioning-and sustained attention might be crucial in this regard.

METHOD

Eighty-five participants were asked to monitor automated aircraft functions. The experimental manipulation consisted of whether or not an initial automation failure was followed by a consecutive failure. Reaction times to the failures were recorded. Participants' working-memory and sustained-attention abilities were assessed with standardized tests.

RESULTS

As expected, participants' reactions to consecutive failures were slower than their reactions to initial failures. In addition, working-memory and sustained-attention abilities enhanced the speed with which participants reacted to failures, more so with regard to consecutive than to initial failures.

CONCLUSION

The findings highlight that operators with better working memory and sustained attention have small advantages when initial failures occur, but their advantages increase across consecutive failures.

APPLICATION

The results stress the need to consider personnel selection strategies to mitigate cognitive lock-up in general and training procedures to enhance the performance of low ability operators.

Detection-Action Linkage in Vigilance: Effects on Workload and Stress

Using a simulated UAV control task in which a vigilance display warned observers of the presence of enemy threats, Gunn et al. (2005) reported that perceived mental workload in relation to the vigilance task was unexpectedly low. The present study did not confirm that finding. It did show, however, that vigilance performance was greater and task induced stress was less among observers who had the opportunity to act upon vigilance signal detections by destroying the enemy threats than among those who detected threats but had no opportunity to counter them. Accordingly, the results point to the importance of a detection-action linkage to enhance signal detection and reduce stress in the performance of vigilance tasks.

Performance, Workload, and Stress in Vigilance: The Power of Choice

Observers were provided the illusion of choice by permitting them to ‘choose’ an easy or a hard version of a vigilance task. Participants were then assigned at random to either the condition they expressed preference for or their non-preferred condition. Participants in the comparison control condition were not offered the opportunity to choose. Task demand was manipulated using event rate variation, divided into high and low event rates. Results indicated that permitting participants a choice regarding ‘difficulty level’ and subsequently assigning them to that level enhanced signal detections but did not reduce their perceived workload and stress. In contrast, offering a choice and then assigning observers to their non-preferred condition impaired performance relative to a condition in which no choice was provided. This pattern of effects was more pronounced at the low compared to the high event rate. These results confirm the importance of motivational effects in vigilance and the impact choice has on performance in tasks requiring sustained attention.

Effects of Sensory Modality on Vigilance Performance and Cerebral Hemovelocity

Using Transcranial Doppler sonography, cerebral blood flow velocity (hemovelocity, CBFV) was recorded from the middle cerebral arteries during the performance of 40-min auditory and visual vigilance tasks. Reductions in stimulus duration were the critical signals for detection in both tasks, which were equated for stimulus salience and discrimination difficulty. Signal detection responses (correct detections and false alarms) and CBFV declined linearly over time in both modalities. In addition, the overall level of CBFV and the temporal decline in this measure were greater in the right than the left cerebral hemisphere. The results support the view that a right hemispheric system is involved in the functional control of vigilance and that this system operates in a similar manner in the auditory and visual channels.

Measuring the Workload of Sustained Attention

The utility of a new measure of perceived mental workload in vigilance, The Multiple Resources Questionnaire (MRQ), was evaluated by comparing its sensitivity against that of the standard measure in this area, the NASA-TLX. Sensitivity was assessed in regard to the effects of a factor previously shown by the NASA-TLX to affect task demand, detecting stimulus presence/absence. Performance efficiency was significantly greater when critical signals for detection were defined by the presence of a target feature than by the absence of that feature. This effect was echoed in higher global workload scores for absence than presence when workload was measured by the NASA-TLX and by a modified version of the MRQ involving an increase in the response range for each item in the scale. Additionally, the MRQ identified resources utilized in the vigilance task that are not reflected in the standard measure. The results indicate that the new scale could be a useful adjunct to the older one.

When and Why Threats Go Undetected: Impacts of Event Rate and Shift Length on Threat Detection Accuracy During Airport Baggage Screening

OBJECTIVE

We aimed to assess the impact of task demands and individual characteristics on threat detection in baggage screeners.

BACKGROUND

Airport security staff work under time constraints to ensure optimal threat detection. Understanding the impact of individual characteristics and task demands on performance is vital to ensure accurate threat detection.

METHOD

We examined threat detection in baggage screeners as a function of event rate (i.e., number of bags per minute) and time on task across 4 months. We measured performance in terms of the accuracy of detection of Fictitious Threat Items (FTIs) randomly superimposed on X-ray images of real passenger bags.

RESULTS

Analyses of the percentage of correct FTI identifications (hits) show that longer shifts with high baggage throughput result in worse threat detection. Importantly, these significant performance decrements emerge within the first 10 min of these busy screening shifts only.

CONCLUSION

Longer shift lengths, especially when combined with high baggage throughput, increase the likelihood that threats go undetected.

APPLICATION

Shorter shift rotations, although perhaps difficult to implement during busy screening periods, would ensure more consistently high vigilance in baggage screeners and, therefore, optimal threat detection and passenger safety.

Sustained Attention in Auditory and Visual Monitoring Tasks: Evaluation of the Administration of a Rest Break or Exogenous Vibrotactile Signals

OBJECTIVE

Performance and mental workload were observed for the administration of a rest break or exogenous vibrotactile signals in auditory and visual monitoring tasks.

BACKGROUND

Sustained attention is mentally demanding. Techniques are required to improve observer performance in vigilance tasks.

METHOD

Participants (N = 150) monitored an auditory or a visual display for changes in signal duration in a 40-min watch. During the watch, participants were administered a rest break or exogenous vibrotactile signals.

RESULTS

Detection accuracy was significantly greater in the auditory than in the visual modality. A short rest break restored detection accuracy in both sensory modalities following deterioration in performance. Participants experienced significantly lower mental workload when monitoring auditory than visual signals, and a rest break significantly reduced mental workload in both sensory modalities. Exogenous vibrotactile signals had no beneficial effects on performance, or mental workload.

CONCLUSION

A rest break can restore performance in auditory and visual vigilance tasks. Although sensory differences in vigilance tasks have been studied, this study is the initial effort to investigate the effects of a rest break countermeasure in both auditory and visual vigilance tasks, and it is also the initial effort to explore the effects of the intervention of a rest break on the perceived mental workload of auditory and visual vigilance tasks. Further research is warranted to determine exact characteristics of effective exogenous vibrotactile signals in vigilance tasks.

APPLICATION

Potential applications of this research include procedures for decreasing the temporal decline in observer performance and the high mental workload imposed by vigilance tasks.

Sherlock: A Semi-automatic Framework for Quiz Generation Using a Hybrid Semantic Similarity Measure

In this paper, we present a semi-automatic system (Sherlock) for quiz generation using linked data and textual descriptions of RDF resources. Sherlock is distinguished from existing quiz generation systems in its generic framework for domain-independent quiz generation as well as in the ability of controlling the difficulty level of the generated quizzes. Difficulty scaling is non-trivial, and it is fundamentally related to cognitive science. We approach the problem with a new angle by perceiving the level of knowledge difficulty as a similarity measure problem and propose a novel hybrid semantic similarity measure using linked data. Extensive experiments show that the proposed semantic similarity measure outperforms four strong baselines with more than 47 % gain in clustering accuracy. In addition, we discovered in the human quiz test that the model accuracy indeed shows a strong correlation with the pairwise quiz similarity.

The configural properties of task stimuli do influence vigilance performance

Sixty-one participants performed a sustained attention task in which they were required to respond to a critical signal requiring feature discrimination. Three separate groups performed the task with different global display configurations. The local feature elements (directional arrow shapes) were displayed on either a circle, a circle broken apart or a reconnected figure. For two of the groups, the entire display consisted of a clear global shape (circle and reconnected), and for one of the groups, the display had no discernible global element (broken circle) despite the critical signal being the same for all the groups. Analyses of hit rate and A' scores indicated that the broken circle group had impaired performance compared to the global figure groups. A configural superiority effect was found in which performance was improved by having a global shape property to the entire display. These results provide a behavioural base for further research utilizing measures of cerebral activation, as cerebral activity during vigilance tasks may be dependent on both task difficulty and hierarchical aspects of the display. The configurable or hierarchical aspects of vigilance displays may be critical in understanding sustained attention performance and its hemispheric lateralization.

Short Stress State Questionnaire

Conscious appraisals of stress, or stress states, are an important aspect of human performance. This article presents evidence supporting the validity and measurement characteristics of a short multidimensional self-report measure of stress state, the Short Stress State Questionnaire (SSSQ; Helton, 2004 ). The SSSQ measures task engagement, distress, and worry. A confirmatory factor analysis of the SSSQ using data pooled from multiple samples suggests the SSSQ does have a three factor structure and post-task changes are not due to changes in factor structure, but to mean level changes (state changes). In addition, the SSSQ demonstrates sensitivity to task stressors in line with hypotheses. Different task conditions elicited unique patterns of stress state on the three factors of the SSSQ in line with prior predictions. The 24-item SSSQ is a valid measure of stress state which may be useful to researchers interested in conscious appraisals of task-related stress.

Vigilance impossible: Diligence, distraction, and daydreaming all lead to failures in a practical monitoring task

In laboratory studies of vigilance, participants watch for unusual events in a "sit and stare" fashion as their performance typically declines over time. But watch keepers in practical settings seldom approach monitoring in such simplistic ways and controlled environments. We observed airline pilots performing routine monitoring duties in the cockpit. Unlike laboratory studies, pilots' monitoring did not deteriorate amidst prolonged vigils. Monitoring was frequently interrupted by other pop-up tasks and misses followed. However, when free from these distractions, pilots reported copious mind wandering. Pilots often confined their mind wandering to times in which their monitoring performance would not conspicuously suffer. But when no convenient times were available, pilots mind wandered anyway and misses ensued. Real-world monitors may be caught between a continuous vigilance approach that is doomed to fail, a dynamic environment that cannot be fully controlled, and what may be an irresistible urge to let one's thoughts drift.

Need for achievement moderates the effect of motive-relevant challenge on salivary cortisol changes

The hypothalamic-pituitary-adrenal (HPA) axis plays a key role in the physiological response to stress, preparing the organism for appropriate action. While some research has examined universally relevant threats, other research has suggested that individual differences may moderate the relationship between stress and cortisol release, such that some individuals exhibit modified reactivity to personally relevant stressors or challenges. In the present study we investigated whether one individual difference-the implicit need for achievement-moderates the effect of motive-relevant challenge on salivary cortisol. Participants' salivary cortisol and felt affect were measured before and after engagement in an achievement task. In the positive- and no-feedback conditions, individuals high in implicit achievement motivation demonstrated increased cortisol response to the task, whereas in the negative feedback condition, individuals high in implicit achievement motivation demonstrated a dampened cortisol response. Furthermore, changes in cortisol were accompanied by changes in felt affect in the same direction, specifically hedonic tone. These results suggest that the HPA axis also responds to non-social-evaluative challenge in a personality-contingent manner.

The impact of heat stress on operative performance and cognitive function during simulated laparoscopic operative tasks

BACKGROUND

Increasing ambient temperature to prevent intraoperative patient hypothermia remains widely advocated despite unconvincing evidence of efficacy. Heat stress is associated with decreased cognitive and psychomotor performance across multiple tasks but remains unexamined in an operative context. We assessed the impact of increased ambient temperature on laparoscopic operative performance and surgeon cognitive stress.

STUDY DESIGN

Forty-two performance measures were obtained from 21 surgery trainees participating in the counter-balanced, within-subjects study protocol. Operative performance was evaluated with adaptations of the validated, peg-transfer, and intracorporeal knot-tying tasks from the Fundamentals of Laparoscopic Surgery program. Participants trained to proficiency before enrollment. Task performance was measured at two ambient temperatures, 19 and 26°C (66 and 79°F). Participants were randomly counterbalanced to initial hot or cold exposure before crossing over to the alternate environment. Cognitive stress was measured using the validated Surgical Task Load Index (SURG-TLX).

RESULTS

No differences in performance of the peg-transfer and intracorporeal knot-tying tasks were seen across ambient conditions. Assessed via use of the six bipolar scales of the SURG-TLX, we found differences in task workload between the hot and cold conditions in the areas of physical demands (hot 10 [3-12], cold 5 [2.5-9], P = .013) and distractions (hot 8 [3.5-15.5], cold 3 [1.5-5.5], P = .001). Participant perception of distraction remained greater in the hot condition on full scoring of the SURG-TLX.

CONCLUSION

Increasing ambient temperature to levels advocated for prevention of intraoperative hypothermia does not greatly decrease technical performance in short operative tasks. Surgeons, however, do report increased perceptions of distraction and physical demand. The impact of these findings on performance and outcomes during longer operative procedures remains unclear.

Psychophysical workload in the operating room: primary surgeon versus assistant

BACKGROUND

Working in the operating room is characterized by high demands and overall workload of the surgical team. Surgeons often report that they feel more stressed when operating as a primary surgeon than in the function as an assistant which has been confirmed in recent studies. In this study, intra-individual workload was assessed in both intraoperative functions using a multidimensional approach that combined objective and subjective measures in a realistic work setting.

METHODS

Surgeons' intraoperative psychophysiologic workload was assessed through a mobile health system. 25 surgeons agreed to take part in the 24-hour monitoring by giving their written informed consent. The mobile health system contained a sensor electronic module integrated in a chest belt and measuring physiological parameters such as heart rate (HR), breathing rate (BR), and skin temperature. Subjective workload was assessed pre- and postoperatively using an electronic version of the NASA-TLX on a smartphone. The smartphone served as a communication unit and transferred objective and subjective measures to a communication server where data were stored and analyzed.

RESULTS

Working as a primary surgeon did not result in higher workload. Neither NASA-TLX ratings nor physiological workload indicators were related to intraoperative function. In contrast, length of surgeries had a significant impact on intraoperative physical demands (p < 0.05; η(2) = 0.283), temporal demands (p < 0.05; η(2) = 0.260), effort (p < 0.05; η(2) = 0.287), and NASA-TLX sum score (p < 0.01; η(2) = 0.287).

CONCLUSIONS

Intra-individual workload differences do not relate to intraoperative role of surgeons when length of surgery is considered as covariate. An intelligent operating management that considers the length of surgeries by implementing short breaks could contribute to the optimization of intraoperative workload and the preservation of surgeons' health, respectively. The value of mobile health systems for continuous psychophysiologic workload assessment was shown.

Vigilance on the move: video game-based measurement of sustained attention

Vigilance represents the capacity to sustain attention to any environmental source of information over prolonged periods on watch. Most stimuli used in vigilance research over the previous six decades have been relatively simple and often purport to represent important aspects of detection and discrimination tasks in real-world settings. Such displays are most frequently composed of single stimulus presentations in discrete trials against a uniform, often uncluttered background. The present experiment establishes a dynamic, first-person perspective vigilance task in motion using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the study of sustained attention. We conclude that the stress of vigilance extends to the new paradigm, but whether the performance decrement emerges depends upon specific task parameters. The development of the task, the issues to be resolved and the pattern of performance, perceived workload and stress associated with performing such dynamic vigilance are reported.

PRACTITIONER SUMMARY

The present experiment establishes a dynamic, first-person perspective movement-based vigilance task using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the evaluation of sustained attention in operational environments in which individuals move as they monitor their environment. Issues addressed in task development are described.

Measuring perceived mental workload in children

Little is known about the mental workload, or psychological costs, associated with information processing tasks in children. We adapted the highly regarded NASA Task Load Index (NASA-TLX) multidimensional workload scale (Hart & Staveland, 1988) to test its efficacy for use with elementary school children. We developed 2 types of tasks, each with 2 levels of demand, to draw differentially on resources from the separate subscales of workload. In Experiment 1, our participants were both typical and school-labeled gifted children recruited from 4th and 5th grades. Results revealed that task type elicited different workload profiles, and task demand directly affected the children's experience of workload. In general, gifted children experienced less workload than typical children. Objective response time and accuracy measures provide evidence for the criterion validity of the workload ratings. In Experiment 2, we applied the same method with 1st- and 2nd-grade children. Findings from Experiment 2 paralleled those of Experiment 1 and support the use of NASA-TLX with even the youngest elementary school children. These findings contribute to the fledgling field of educational ergonomics and attest to the innovative application of workload research. Such research may optimize instructional techniques and identify children at risk for experiencing overload.