Monitoring Task Performance Research Articles

Experimental Investigation of Task Performance and Human Vigilance in Different Noise Environments

Twelve healthy male college-age students were recruited to investigate the effects of different noise exposure conditions on complex task performance and vigilance. During each noise exposure, the Multi-Attribute Task Battery (MATB) with low, medium, and high mental workloads were conducted in the order designated by the Latin square method. Meanwhile, a psychomotor vigilance test (PVT) was used to evaluate human vigilance. Heart rate variability (HRV) signals were also collected while participants performed the tasks. The generalized additive mixed-effect model (GAMM) results showed that the increased mental workload had an inverted U-shaped effect on MATB task performance. Noise exposure had no significant impact on the overall performance of MATB tasks. However, when exposed to increased noise sharpness at low mental workloads, Tracking Task (TRA) performance significantly decreased, whereas the System Monitoring Task (SYS) performance was significantly improved. In addition, higher noise sound pressure level and sharpness would impair human vigilance, which was reflected in a lower mean sample entropy of HRV and worse performance on the PVT. The results indicated that noise control in the workplace should consider both sound pressure level and sharpness.

Functional organisation for verb generation in children with developmental language disorder

Developmental language disorder (DLD) is characterised by difficulties in learning one's native language for no apparent reason. These language difficulties occur in 7% of children and are known to limit future academic and social achievement. Our understanding of the brain abnormalities associated with DLD is limited. Here, we used a simple four-minute verb generation task (children saw a picture of an object and were instructed to say an action that goes with that object) to test children between the ages of 10–15 years (DLD N = 50, typically developing N = 67). We also tested 26 children with poor language ability who did not meet our criteria for DLD. Contrary to our registered predictions, we found that children with DLD did not have (i) reduced activity in language relevant regions such as the left inferior frontal cortex; (ii) dysfunctional striatal activity during overt production; or (iii) a reduction in left-lateralised activity in frontal cortex. Indeed, performance of this simple language task evoked activity in children with DLD in the same regions and to a similar level as in typically developing children. Consistent with previous reports, we found sub-threshold group differences in the left inferior frontal gyrus and caudate nuclei, but only when analysis was limited to a subsample of the DLD group (N = 14) who had the poorest performance on the task. Additionally, we used a two-factor model to capture variation in all children studied (N = 143) on a range of neuropsychological tests and found that these language and verbal memory factors correlated with activity in different brain regions. Our findings indicate a lack of support for some neurological models of atypical language learning, such as the procedural deficit hypothesis or the atypical lateralization hypothesis, at least when using simple language tasks that children can perform. These results also emphasise the importance of controlling for and monitoring task performance.

Shoulder Muscular Fatigue From Static Posture Concurrently Reduces Cognitive Attentional Resources.

The goal of this work is to determine whether muscular fatigue concurrently reduces cognitive attentional resources in technical tasks for healthy adults. Muscular fatigue is common in the workplace but often dissociated with cognitive performance. A corpus of literature demonstrates a link between muscular fatigue and cognitive function, but few investigations demonstrate that the instigation of the former degrades the latter in a way that may affect technical task completion. For example, laparoscopic surgery increases muscular fatigue, which may risk attentional capacity reduction and undermine surgical outcomes. A total of 26 healthy participants completed a dual-task cognitive assessment of attentional resources while concurrently statically fatiguing their shoulder musculature until volitional failure, in a similar loading pattern observed in laparoscopic procedures. Continuous and discrete monitoring task performance was recorded to reflect attentional resources. Electromyography of the anterior deltoid and descending trapezius, as well as self-assessment surveys indicated fatigue occurrence; continuous tracking error, tracking velocity, and response time significantly increased with muscular fatigue. Muscular fatigue concurrently degrades cognitive attentional resources. Complex tasks that rely on muscular and cognitive performance should consider interventions to reduce muscular fatigue to also preserve cognitive performance.

Retention of a standard operating procedure under the influence of social stress and refresher training in a simulated process control task

In a simulated process control task, we investigated the effects of refresher training and acute social stress on performing a standard operating procedure (SOP) containing a production and monitoring task and knowledge recall after a retention interval of two weeks. In a 2 × 2 between-group design (Factor 1: induced social stress, Factor 2: refresher training), 76 engineering students performed an SOP at t1 in week 1 and at t2 in week 3. A MANOVA in week three (t2) indicated a main effect of the refresher training for the SOP execution containing a production and a monitoring task and an impairing effect of stress on the monitoring task. That means that after a retention interval, stress mainly affects the SOP’s monitoring task. An additional correlational analysis showed that knowledge test performance is negatively associated with cortisol level and that retentivity is a strong predictor for knowledge test performance and production task performance, too.Practitioner Summary: We investigated effects of social stress and refresher training on performing a standard operating procedure (SOP) after a retention interval of two weeks. The impact of social stress reduced the monitoring task performance as part of the SOP, but not the production outcome. Without refresher training, performance is significantly worse.Abbreviation: SOP: Standard Operating Procedure; MANOVA: Multivariate Analysis of Variance; CSB: Chemical Safety and Hazard Investigation Board; TSST: Trierer Social Stress Test; P-TSST: Placebo Trierer Social Stress Test; WaTrSim: Water Treatment Simulation; HPA axis: hypothalamic pituitary adrenal axis; WIT-2: Wilde Intelligenztest – 2; SPSS: Statistical Package for the Social Sciences; ANOVA: Analysis of Variance.

Temporally sensitive neural measures of inhibition in preschool children across a spectrum of irritability.

Irritability is a prominent feature of chronic mental disorders and a developmental marker of their early emergence. The most salient feature of irritability in early childhood is temper tantrums. While temper tantrums are normative in young children, they can be clinically concerning when they are dysregulated, very frequent, and/or occur in unexpected contexts. The present study uses behavioral and event-related brain potential (ERP) measures to characterize the relationship between irritability and neural markers of response inhibition in very young children. Forty-six children (ages 4-7years) completed a go/no-go task under nonfrustrating and frustrating conditions. ERPs elicited by go and no-go stimuli were examined as a function of frustration condition and irritability, operationalized via the well-validated Temper Loss scale of the Multidimensional Assessment Profile of Disruptive Behavior (MAP-DB). Higher Temper Loss scores were associated with larger N2no-go amplitudes and reduced no-go accuracy during frustration. This suggests that higher levels of irritability corresponded with increased conflict monitoring and poorer task performance during frustration. These findings add to a developing literature identifying the neurocognitive markers of varying levels of irritability in young children.

Investigating the roles of medial prefrontal and superior temporal cortex in source monitoring

Source monitoring, or the ability to recall the origin of information, is a crucial aspect of remembering past experience. One facet of this, reality monitoring, refers to the ability to distinguish between internally generated and externally generated information, biases in which have previously been associated with auditory verbal hallucinations in schizophrenia. Neuroimaging evidence suggests that medial prefrontal and superior temporal (STG) regions may play a role in reality monitoring for auditory verbal information, with evidence from a previous neurostimulation experiment also suggesting that modulation of excitability in STG may affect reality monitoring task performance. Here, two experiments are reported that used transcranial direct current stimulation (tDCS) to modulate excitability in medial prefrontal and superior temporal cortex, to further investigate the role of these brain regions in reality monitoring. In the first experiment (N = 36), tDCS was applied during the encoding stage of the task, while in the second experiment, in a separate sample (N = 36), it was applied during the test stage. There was no effect of tDCS compared to a sham condition in either experiment, with Bayesian analysis providing evidence for the null hypothesis in both cases. This suggests that tDCS applied to superior temporal or medial prefrontal regions may not affect reality monitoring performance, and has implications for theoretical models that link reality monitoring to the therapeutic effect of tDCS on auditory verbal hallucinations.

A Sequential Sampling Algorithm for Multistage Static Coverage Problems

In many system-engineering problems, such as surveillance, environmental monitoring, and cooperative task performance, it is critical to allocate limited resources within a restricted area optimally. Static coverage problem (SCP) is an important class of the resource allocation problem. SCP focuses on covering an area of interest so that the activities in that area can be detected with high probabilities. In many practical settings, primarily due to financial constraints, a system designer has to allocate resources in multiple stages. In each stage, the system designer can assign a fixed number of resources, i.e., agents. In the multistage formulation, agent locations for the next stage are dependent on previous-stage agent locations. Such multistage static coverage problems are nontrivial to solve. In this paper, we propose an efficient sequential sampling algorithm to solve the multistage static coverage problem (MSCP) in the presence of resource intensity allocation maps (RIAMs) distribution functions that abstract the event that we want to detect/monitor in a given area. The agent's location in the successive stage is determined by formulating it as an optimization problem. Three different objective functions have been developed and proposed in this paper: (1) L2 difference, (2) sequential minimum energy design (SMED), and (3) the weighted L2 and SMED. Pattern search (PS), an efficient heuristic algorithm has been used as optimization algorithm to arrive at the solutions for the formulated optimization problems. The developed approach has been tested on two- and higher dimensional functions. The results analyzing real-life applications of windmill placement inside a wind farm in multiple stages are also presented.

부정적 자기 도식 수준에 따른 출처감찰과제 수행

본 연구는 우울 성향 집단에서 부정적 자기관련 진술문의 출처기억의 판단에 편향이 있는지를 확인하고, 출처감찰과제의 수행이 우울관련 설문지와 어떤 관계를 갖고 있는지를 검토하였다. 실험 참가자는 모두 73명의 대학생으로, 부정적 자동적 사고 척도(ATQ-N) 점수 1표준편차를 기준으로 높은 집단과 낮은 집단을 구분하였다. 실험실에서 참가자들은 먼저 부정적 자기관련 진술문과 잡학상식 문항을 남녀목소리로 듣는데, 이때 여자는 참을 말하고 남자는 거짓을 말한다는 출처정보를 연합한다. 그 후 시각적으로 제시된 문장을 읽고 참인지거짓인지 들은 적이 없는 것인지를 판단해야 한다. 연구 결과, ATQ-N 점수가 높은 집단은 부정적 자기관련 진술문을 참으로 판단하는 반응률과 참으로 분류해야 하는 경우의 정답률이 더 높았고, 거짓 범주에 대한 출처감찰은 반추 및 부정적 사고를 믿는 정도(ATQ-NB)와 부적 상관이 있었다. 반면, 반추와 부정적 사고를 믿는 정도는 거짓 범주에 대한 반응과 상관이 높았다. 본 연구의 결과는 부적응적 도식의 출처정보에 대한 자동적 처리 과정이 우울증의 인지에 중요한 역할을 한다는 시사점을 주었다. 마지막으로 본 연구의 한계점과 후속 연구를위한 제언이 논의되었다.

A Novel Sampling Technique for Probabilistic Static Coverage Problems

Resource allocation in the presence of constraints is an important activity in many systems engineering problems such as surveillance, infrastructure planning, environmental monitoring, and cooperative task performance. The resources in many important problems are agents such as a person, machine, unmanned aerial vehicles (UAVs), infrastructures, and software. Effective execution of a given task is highly correlated with effective allocation of resources to execute the task. An important class of resource allocation problem in the presence of limited resources is static coverage problem. In static coverage problems, it is necessary to allocate resources (stationary configuration of agents) to cover an area of interest so that an event or spatial property of the area can be detected or monitored with high probability. In this paper, we outline a novel sampling algorithm for the static coverage problem in presence of probabilistic resource intensity allocation maps (RIAMs). The key intuition behind our sampling approach is to use the finite number of samples to generate an accurate representation of RIAM. The outlined sampling technique is based on an optimization framework that approximates the RIAM with piecewise linear surfaces on the Delaunay triangles and optimizes the sample placement locations to decrease the difference between the probability distribution and Delaunay triangle surface. Numerical results demonstrate that the algorithm is robust to the initial sample point locations and has superior performance in a wide range of theoretical problems and real-life applications. In a real-life application setting, we demonstrate the efficacy of the proposed algorithm to predict the position of wind stations for monitoring wind speeds across the U.S. The algorithm is also used to give recommendations on the placement of police cars in San Francisco and weather buoys in Pacific Ocean.

Formant Frequencies under Cognitive Load: Effects and Classification

Cognitive load measurement systems measure the mental demand experienced by human while performing a cognitive task, which is useful in monitoring and enhancing task performance. Various speech-based systems have been proposed for cognitive load classification, but the effect of cognitive load on the speech production system is still not well understood. In this work, we study formant frequencies under different load conditions and utilize formant frequency-based features for automatic cognitive load classification. We find that the slope, dispersion, and duration of vowel formant trajectories exhibit changes under different load conditions; slope and duration are found to be useful features in vowel-based classification. Additionally, 2-class and 3-class utterance-based classification results, evaluated on two different databases, show that the performance of frame-based formant features was comparable, if not better than, baseline MFCC features.

Encoding problem‐solving strategies in prefrontal cortex: activity during strategic errors

The primate prefrontal cortex (PF) plays a central role in choosing goals and strategies. To better understand its mechanisms, we recorded from PF neurons as monkeys used abstract response strategies to select a spatial goal. A visual cue, selected randomly from a set of three cues, appeared on each trial. All three cues were novel when neuronal recording commenced. From trial to trial, the cue could have either been repeated or changed from the previous trial; these were called repeat trials and change trials, respectively. On repeat trials, the monkeys used a Repeat-stay strategy to gain a reward by choosing the same spatial goal as on the previous trial; on change trials, they used a Change-shift strategy to reject the previous goal in favour of an alternative. We reported previously that when monkeys performed the task correctly, many PF neurons had activity encoding one of these two strategies. The monkeys sometimes chose the incorrect strategy, however. Strategy coding was weak or absent during the cue period of error trials which was, for correct trials, the time when the monkeys used a strategy to choose a future goal. By contrast, later in the trial, after the chosen goal had been attained and the monkeys awaited feedback, strategy coding was present and it reflected the strategy used, whether correct or incorrect. The weak cue-period strategy signal could, whatever its cause, have contributed to the errors made, whereas the activity prior to feedback suggests a role in monitoring task performance.

Cerebral compensation during motor imagery in Parkinson's disease

In neurodegenerative disorders, neural damage can trigger compensatory mechanisms that minimize behavioural impairments. Here, we aimed at characterizing cerebral compensation during motor imagery in Parkinson's disease (PD), while controlling for altered motor execution and sensory feedback. We used a within-patient design to compare the most and least affected hand in 19 right-handed PD patients with markedly right-lateralized symptoms. We used a motor imagery (MI) task in which the patients were required to judge the laterality of hand images, rotated either in a lateral or in a medial orientation with respect to the body sagittal plane. This design allowed us to compare cerebral activity (using fMRI) evoked by MI of each hand separately, while objectively monitoring task performance. Reaction times and parieto-premotor activity increased in a similar manner as a function of stimulus rotation during motor imagery of left and right hands. However, patients were markedly slower when judging images of the affected hand in lateral orientations, and there was a corresponding increase in activity in the right extrastriate body area (EBA) and occipito-parietal cortex during mental rotation of the affected hand. Furthermore, these regions increased their connectivity towards the left PMd for right (affected) hands in a lateral orientation. We infer that, in strongly lateralized PD patients, motor imagery of the most-affected hand exploits additional resources in extrastriate visual areas. These findings characterize the cerebral bases of the increased dependence on visual information processing during the generation of motor plans in PD, pointing to its compensatory role.

Implementing Adaptive Function Allocation

Adaptive function allocation, in which the control of tasks dynamically shifts between humans and machines, has been proposed as an alternative to traditional static allocation, in which task control is assigned during system design and remains unchanged during operations. Understanding adaptive allocation and its effects on operator performance and workload is limited by sparse systematic research and an underdeveloped theoretical framework for implementation. The purpose of this research was to determine the efficacy of adaptive allocation by implementing adaptive allocation in a multiple task aviation simulation based on a taxonomy with facets of invocation philosophy and allocation strategy. Pilot performance was evaluated to determine benefits and costs for the implementation of adaptive allocation in a multitask aviation simulation with tracking, system monitoring, and target identification tasks. The results provide support for the implementation of adaptive allocation based on a hybrid model comprising elements of operator performance and mission relevant variables. Implementation of adaptive allocation was an effective countermeasure to the predictable decrease in tracking performance associated with the initial presentation of a surface target. Benefits were also identified for monitoring task performance despite the fact that the monitoring task was not modified by the implementation of automation. Secondary benefits included improved time estimates. Potential costs of adaptive allocation included performance variability in the tracking when task partitioning was the adaptive strategy. Implications of results for design, philosophy, and theory are presented.

EEG, heart rate and reaction time in humans: Effect of variable vs. fixed interval repetitive stimuli

Visual motor reaction time (RT) change was measured in 12 normal adults exposed to iterative, prolonged, photic stimulation of two kinds: (a) isochronous (IS) and (b) stochastic (SS). EEG, EKG, eye and palpebral movements were continuously recorded. The mean RT for all subjects was shorter for the IS situation. Stochastic stimulation produced an increase in RT variability. A facilitation of the monitoring task performance during the first 2 min of IS stimulation was observed. It was found that monitoring task performance was positively correlated with the amount of alpha rhythm in the EEG record. A “predictive”, brief, attenuation of alpha rhythm appeared when the subject's monitoring task was maintained at a good performance level. It is assumed that this is a sign of expectancy. Deterioration of the monitoring task performance was accompanied by a decrement of the EEG photic driving response and slowing of hear rate. These results are discussed in relation to sensory habituation and to the internal appreciation of time.