Varying Task Demands Research Articles

Mental Workload as a Predictor of ATCO’s Performance: Lessons Learnt from ATM Task-Related Experiments

Air Traffic Controllers’ (ATCos) mental workload is likely to remain the specific greatest functional limitation on the capacity of the Air Traffic Management (ATM) system. Developing computational models to monitor mental workload and task complexity is essential for enabling ATCOs and ATM systems to adapt to varying task demands. Most methodologies have computed task complexity based on basic parameters such as air-traffic density; however, literature research has shown that it also depends on many other factors. In this paper, we present a study in which we explored the possibility of predicting task complexity and performance through mental workload measurements of participants performing an ATM task in an air-traffic control simulator. Our findings suggest that mental workload measurements better predict poor performance and high task complexity peaks than other established factors. This underscores their potential for research into how different ATM factors affect task complexity. Understanding the role and the weight of these factors in the overall task complexity confronted by ATCos constitutes one of the biggest challenges currently faced by the ATM sphere and would significantly contribute to the safety of our sky.

Optimization of Predefined-Time Agent-Scheduling Strategy Based on PPO

In this paper, we introduce an agent rescue scheduling approach grounded in proximal policy optimization, coupled with a singularity-free predefined-time control strategy. The primary objective of this methodology is to bolster the efficiency and precision of rescue missions. Firstly, we have designed an evaluation function closely related to the average flying distance of agents, which provides a quantitative benchmark for assessing different scheduling schemes and assists in optimizing the allocation of rescue resources. Secondly, we have developed a scheduling strategy optimization method using the Proximal Policy Optimization (PPO) algorithm. This method can automatically learn and adjust scheduling strategies to adapt to complex rescue environments and varying task demands. The evaluation function provides crucial feedback signals for the PPO algorithm, ensuring that the algorithm can precisely adjust the scheduling strategies to achieve optimal results. Thirdly, aiming to attain stability and precision in agent navigation to designated positions, we formulate a singularity-free predefined-time fuzzy adaptive tracking control strategy. This approach dynamically modulates control parameters in reaction to external disturbances and uncertainties, thus ensuring the precise arrival of agents at their destinations within the predefined time. Finally, to substantiate the validity of our proposed approach, we crafted a simulation environment in Python 3.7, engaging in a comparative analysis between the PPO and the other optimization method, Deep Q-network (DQN), utilizing the variation in reward values as the benchmark for evaluation.

Unveiling the dynamics and impact of emotional presence in collaborative learning

This study aims to understand the dynamics and impact of emotional presence in a collaborative learning environment and its effects on the learning process and outcomes. Emotional presence, defined as the experience of emotion arising from cognitive appraisals in learner-environment interactions, encompasses four dimensions: interest-curiosity, emotional regulation, expression management, and emotional awareness. Using a mixed-methods approach, we surveyed 33 Japanese college students engaged in collaborative learning activities and conducted in-depth interviews with 10 participants to gather qualitative insights. The study revealed that emotional presence evolves throughout the collaborative process, with increased emotional regulation in response to complex tasks, reflecting learners’ adaptations to varying task demands. It highlighted the importance of emotional regulation in shaping the learning process and improving outcomes in collaborative learning. Our findings suggest that heightened emotional presence, with increased emotional awareness and regulation, fosters cognitive development and learner well-being, supporting more effective and fulfilling collaborative learning experiences. The study also emphasizes the crucial role of cognitive appraisal in shaping emotional experiences, significantly influencing outcomes in technology-enhanced environments. The study concludes by proposing future research directions, such as examining the longitudinal impacts of emotional presence and exploring interventions to enhance emotional regulation skills in diverse learning contexts.

Facial emotion recognition in children of parents with a mental illness

ObjectiveFacial emotion recognition (FER) is a fundamental social skill essential for adaptive social behaviors, emotional development, and overall well-being. FER impairments have been linked to various mental disorders, making it a critical transdiagnostic mechanism influencing the development and trajectory of mental disorders. FER has also been found to play a role in the transgenerational transmission of mental disorders, with the majority of research suggesting FER impairments in children of parents with a mental illness (COPMI). Previous research primarily concentrated on COPMI of parents with internalizing disorders, which does not cover the full spectrum of outpatient mental health service populations. Furthermore, research focuses on varying components of FER by using different assessment paradigms, making it challenging to compare study results. To address these gaps, we comprehensively investigated FER abilities in COPMI using multiple tasks varying in task characteristics.MethodsWe included 189 children, 77 COPMI and 112 children of parents without a diagnosed mental illness (COPWMI), aged 6 to 16 years. We assessed FER using three tasks with varying task demands: an emotional Go/NoGo task, a morphing task, and a task presenting short video sequences depicting different emotions. We fitted separate two-level hierarchical Bayesian models (to account for sibling pairs in our sample) for reaction times and accuracy rates for each task. Good model fit was assured by comparing models using varying priors.ResultsContrary to our expectations, our results revealed no general FER deficit in COPMI compared to COPWMI. The Bayesian models fitted for accuracy in the morphing task and Go/NoGo task yielded small yet significant effects. However, Bayes factors fitted for the models suggested that these effects could be due to random variations or noise in the data.ConclusionsOur study does not support FER impairments as a general feature of COPMI. Instead, individual factors, such as the type of parental disorder and the timing of its onset, may play a crucial role in influencing FER development. Future research should consider these factors, taking into account the diverse landscape of parental mental disorders.

Rectified Latent Variable Model-Based EMG Factorization of Inhibitory Muscle Synergy Components Related to Aging, Expertise and Force-Tempo Variations.

Muscle synergy has been widely acknowledged as a possible strategy of neuromotor control, but current research has ignored the potential inhibitory components in muscle synergies. Our study aims to identify and characterize the inhibitory components within motor modules derived from electromyography (EMG), investigate the impact of aging and motor expertise on these components, and better understand the nervous system's adaptions to varying task demands. We utilized a rectified latent variable model (RLVM) to factorize motor modules with inhibitory components from EMG signals recorded from ten expert pianists when they played scales and pieces at different tempo-force combinations. We found that older participants showed a higher proportion of inhibitory components compared with the younger group. Senior experts had a higher proportion of inhibitory components on the left hand, and most inhibitory components became less negative with increased tempo or decreased force. Our results demonstrated that the inhibitory components in muscle synergies could be shaped by aging and expertise, and also took part in motor control for adapting to different conditions in complex tasks.

The adaptive flexibility of rhythmic attentional sampling in attending to multiple targets.

Recent behavioral and neural imaging studies revealed a rhythmic sampling in the theta-band (3-8 Hz) of attention. Such observation indicates that visual attention sequentially visits attended locations rapidly and periodically to cover multiple spatial locations, which is believed driven by a general sampling mechanism with a sampling rate invariant to the number of targets. However, a general sampling mechanism with a fixed rate would lead to the consequence that it would take longer time for attention to revisit the same item when attention needs to cover more items, which could impair perceptual continuity. It is unclear whether and how the attentional sampling mechanism can flexibly adapt to varying task demand to balance between covering more items and maintaining stable perception. Here with five behavioral experiments, we investigated how the sequential sampling mechanism adapts to the need of attending to from one to four locations. With state-of-the-art analysis methods, results show clear evidence of sequential sampling in attending to multiple locations, that both theta-band oscillations and phase-shift among different locations were observed in the behavioral performance. At each location, the oscillation period increased when the attended locations increased from one to three, maintaining a relatively stable attention-dwelling time at each location. Critically, oscillation period remained essentially the same from three to four, suggesting a flexible task-driven acceleration of attentional sampling to keep the revisiting duration within a reasonable range. Thus, our results reveal that the generally stable rhythmic attention mechanism could flexibly adjust its sampling rate to accommodate increased attentional demands. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Lateralized Functional Connectivity of the Sensorimotor Cortex and its Variations During Complex Visuomotor Tasks.

Previous studies have shown that the left hemisphere dominates motor function, often observed through homotopic activation measurements. Using a functional connectivity approach, this study investigated the lateralization of the sensorimotor cortex during handwriting and drawing, two complex visuomotor tasks with varying contextual demands. We found that both left- and right-lateralized connectivity in the primary motor cortex (M1), dorsal premotor cortex (PMd), somatosensory cortex, and visual regions were evident in adults (males and females), primarily in an interhemispheric integrative fashion. Critically, these lateralization tendencies remained highly invariant across task contexts, representing a task-invariant neural architecture for encoding fundamental motor programs consistently implemented in different task contexts. Additionally, the PMd exhibited a slight variation in lateralization degree between task contexts, reflecting the ability of the high-order motor system to adapt to varying task demands. However, connectivity-based lateralization of the sensorimotor cortex was not detected in 10-year-old children (males and females), suggesting that the maturation of connectivity-based lateralization requires prolonged development. In summary, this study demonstrates both task-invariant and task-sensitive connectivity lateralization in sensorimotor cortices that support the resilience and adaptability of skilled visuomotor performance. These findings align with the hierarchical organization of the motor system and underscore the significance of the functional connectivity-based approach in studying functional lateralization.

Scanpath Regularity as an Index of Reading Comprehension

ABSTRACT Purpose Recent research on the potential of using eye-tracking to measure reading comprehension ability suggests that the relationship between standard eye-tracking measures and reading comprehension is influenced by differences in task demands between comprehension assessments. We compared standard eye-tracking measures and scanpath regularity as predictors of reading comprehension scores. Method We used a dataset in which 79 participants (mean age: 22 years, 82% females, 76% monolingual English speakers) were administered three widely-used reading comprehension assessments with varying task demands while their eye movements were monitored: the York Assessment of Reading for Comprehension; (YARC), the Gray Oral Reading Test; (GORT-5), and the sentence comprehension subtest of the Wide Range Achievement Test; (WRAT-4). Results Results showed that scanpath regularity measures, similarly to standard eye-tracking measures, were influenced by differences in task demands between the three tests. Nevertheless, both types of eye-tracking measures made unique contributions as predictors of comprehension and the best set of predictors included both standard eye-tracking measures and at least one scanpath measure across tests. Conclusion The results provide evidence that scanpaths capture differences in eye-movement patterns missed by standard eye-tracking measures. Overall, the results highlight the effect of task demands on eye-movement behavior and suggest that reading goals and task demands need to be considered when interpreting eye-tracking data.

Adaptive coding of stimulus information in human frontoparietal cortex during visual classification

The neural mechanisms of how frontal and parietal brain regions support flexible adaptation of behavior remain poorly understood. Here, we used functional magnetic resonance imaging (fMRI) and representational similarity analysis (RSA) to investigate frontoparietal representations of stimulus information during visual classification under varying task demands. Based on prior research, we predicted that increasing perceptual task difficulty should lead to adaptive changes in stimulus coding: task-relevant category information should be stronger, while task-irrelevant exemplar-level stimulus information should become weaker, reflecting a focus on the behaviorally relevant category information. Counter to our expectations, however, we found no evidence for adaptive changes in category coding. We did find weakened coding at the exemplar-level within categories however, demonstrating that task-irrelevant information is de-emphasized in frontoparietal cortex. These findings reveal adaptive coding of stimulus information at the exemplar-level, highlighting how frontoparietal regions might support behavior even under challenging conditions.

Using Eye‐Tracking Measures to Predict Reading Comprehension

ABSTRACTThis study examined the potential of eye‐tracking as a tool for assessing reading comprehension. We administered three widely used reading comprehension tests with varying task demands to 79 typical adult readers while monitoring their eye movements. In the York Assessment of Reading for Comprehension (YARC), participants were given passages of text to read silently, followed by comprehension questions. In the Gray Oral Reading Test (GORT‐5), participants were given passages of text to read aloud, followed by comprehension questions. In the sentence comprehension subtest of the Wide Range Achievement Test (WRAT‐4), participants were asked to provide a missing word in sentences that they read silently (i.e., a cloze task). Linear models predicting comprehension scores from eye‐tracking measures yielded different results for the three tests. Eye‐tracking measures explained significantly more variance than reading‐speed data for the YARC (four times better), GORT (three times better), and the WRAT (1.3 time better). Importantly, there was no common strong predictor for all three tests. These results support growing recognition that reading comprehension tests do not measure the same cognitive processes, and that participants adapt their reading strategies to the tests' varying task demands. This study also suggests that eye‐tracking may provide a useful alternative for measuring reading comprehension.

Scene hierarchy structures object representations while flexibly adapting to varying task demands

Objects are arranged in the environment following certain rules which we have termed “scene grammar”, that we exploit to perceive and interact with objects in an efficient way. We have recently proposed that this organization is hierarchical: objects are grouped together based on the scene they typically appear in (e.g., bathroom); based on the different spatial clusters of objects within a scene (“phrases”, e.g., the sink phrase); and based on the status they have within a phrase, where one object (“anchor”, e.g., the sink) typically holds strong predictions about the identity and position of other objects (“local objects”, e.g., a toothbrush). Here we investigate if mental representations of objects reflect this hierarchy and which behavioural goal strengthens this organization. To do so, we collected pairwise similarity judgments for triplets of everyday objects, using an odd-one-out task with different task instructions: in one case, similarity had to be judged based on action goals performed with these objects; in another case, similarity was judged based on visual appearance of objects; finally, similarity ratings were collected without explicit instructions. Results showed that measures of scene hierarchy had stronger impact on similarity judgments for the “action goal” task and the “no instructions” task than for the “visual appearance” task; some aspects of the hierarchy, like “phrase” organization, were even more important to make similarity judgments based on action goals than without explicit instructions. Moreover, measures that estimate visual features of objects had a stronger effect on similarity when judged based on visual appearance than in the other tasks. To conclude, our study shows that scene hierarchy shapes mental representation of objects and that this cognitive organization can flexibly change according to behavioural goals. Besides, it suggests that scene hierarchy is exploited with the purpose of efficient interaction with objects in the environment.

Emotional Valence in the Eye Region Modulates the Attentional Blink in a Task-Dependent Manner: Evidence from Event-Related Potentials.

Although emotional expressions conveyed by the eye regions are processed efficiently, little is known regarding the relationship between emotional processing of isolated eye regions and temporal attention. In this study, we conducted three rapid serial visual presentation (RSVP) experiments with varying task demands (emotion discrimination, eye detection, eyes ignored) related to the first target (T1) to investigate how the perception of emotional valence in the eye region (T1: happy, neutral, fearful) impacts the identification of a second target (T2: neutral houses). Event-related potential (ERP) findings indicated that fearful stimuli reliably increased N170 amplitude regardless of the emotional relevance of task demands. The P3 component exhibited enhanced responses to happy and fearful stimuli in the emotion discrimination task and to happy eye regions in the eye detection task. Analysis of T2-related ERPs within the attentional blink period revealed that T2 houses preceded by fearful and happy stimuli elicited larger N2 and P3 amplitudes than those preceded by neutral stimuli only in the emotion discrimination task. Together, these findings indicate that attention to affective content conveyed by the eyes can not only amplify the perceptual analysis of emotional eye regions but also facilitate the processing of a subsequent target.

Accuracy and effort costs together lead to temporal asynchrony of multiple motor commands.

The timing of motor commands is critical for task performance. A well-known example is rapidly raising the arm while standing upright. Here, reaction forces from the arm movement to the body are countered by leg and trunk muscle activity starting before any sensory feedback from the perturbation and often before the onset of arm muscle activity. Despite decades of research on the patterns, modifiability, and neural basis of these "anticipatory postural adjustments," it remains unclear why asynchronous motor commands occur. Simple accuracy considerations appear unlikely since temporally advanced motor commands displace the body from its initial position. Effort is a credible and overlooked factor that has successfully explained coordination patterns of many behaviors including gait and reaching. We provide the first use of optimal control to address this question. Feedforward commands were applied to a body mass mechanically linked to a rapidly moving limb mass. We determined the feedforward actions with the lowest cost according to an explicit criterion, accuracy alone versus accuracy + effort. Accuracy costs alone led to synchronous activation of the body and limb controllers. Adding effort to the cost resulted in body commands preceding limb commands. This sequence takes advantage of the body's momentum in one direction to counter the limb's reaction force in the opposite direction, allowing a lower peak command and lower integral. With a combined accuracy + effort cost, temporal advancement was further impacted by various task goals and plant dynamics, replicating previous findings and suggesting further studies using optimal control principles.NEW & NOTEWORTHY An important goal in the fields of sensorimotor neuroscience and biomechanics is to explain the timing of different muscles during behavior. Here, we propose that energy and accuracy considerations underlie the asynchronous onset of postural and arm muscles during rapid movement. Our novel model-based framework replicates a broad range of observations across varying task demands and plant dynamics and offers a new perspective to study motor timing.

The role of conscious perception in semantic processing: Testing the action trigger hypothesis

Finding that invisible primes affect categorization of visible targets (response priming) is held to demonstrate that semantic processing does not require conscious perception. However, the effects are typically very small, they do not indicate whether conscious perception enhances response priming and they often reflect visuo-motor rather than semantic processing. Here, we compared response priming elicited by liminal words when these were clearly seen vs missed, while participants categorized target animals’ names. We varied task demands to induce visuo-motor vs semantic processing. Conscious perception strongly enhanced both visuo-motor and semantic response priming. In line with the Action Trigger Hypothesis, task demands modulated processing of both missed and consciously perceived primes. Finally, conscious and unconscious response priming showed diverging patterns on fast and on slow trials, a dissociation suggesting that priming was not contaminated by conscious priming. We conclude that the impact of unconscious stimuli is small and task-dependent.

Natural vs forced language switching: Free selection and consistent language use eliminate significant performance costs and cognitive demands in the brain

Bilinguals are known to switch language spontaneously in everyday conversations, even if there are no external requirements to do so. However, in the laboratory setting, language control is often investigated using forced switching tasks, which result in significant performance costs. The present study assessed whether switching would be less costly when performed in a more natural fashion, and what factors might account for this. Mandarin-English bilinguals engaged in language switching under three different contexts with varied task demands. We examined two factors which may be characteristic of natural switching: (i) freedom of language selection; (ii) consistency of language used to name each item. Participants’ brain activities were recorded using magnetoencephalography (MEG), along with behavioural measures of reaction speed and accuracy. The natural context (with both free selection and consistent language use for each item) produced better performance overall, showing reduced mixing cost and no significant switch cost. The neural effect of language mixing was also reversed in this context, suggesting that freely mixing two languages was easier than staying in a single language. Further, while switching in the forced context elicited increased brain activity in the right inferior frontal gyrus, this switch effect disappeared when the language used to name each item was consistent. Together, these findings demonstrate that the two factors above conjointly contribute to eliminating significant performance costs and cognitive demands associated with language switching and mixing. Such evidence aligns with lexical selection models which do not assume bilingual production to be inherently effortful.

Does What We See Shape History? Examining Workload History as a Function of Performance and Ambient/Focal Visual Attention

Changes in task demands can have delayed adverse impacts on performance. This phenomenon, known as the workload history effect, is especially of concern in dynamic work domains where operators manage fluctuating task demands. The existing workload history literature does not depict a consistent picture regarding how these effects manifest, prompting research to consider measures that are informative on the operator's process. One promising measure is visual attention patterns, due to its informativeness on various cognitive processes. To explore its ability to explain workload history effects, participants completed a task in an unmanned aerial vehicle command and control testbed where workload transitioned gradually and suddenly. The participants’ performance and visual attention patterns were studied over time to identify workload history effects. The eye-tracking analysis consisted of using a recently developed eye-tracking metric called coefficient K , as it indicates whether visual attention is more focal or ambient. The performance results found workload history effects, but it depended on the workload level, time elapsed, and performance measure. The eye-tracking analysis suggested performance suffered when focal attention was deployed during low workload, which was an unexpected finding. When synthesizing these results, they suggest unexpected visual attention patterns can impact performance immediately over time. Further research is needed; however, this work shows the value of including a real-time visual attention measure, such as coefficient K , as a means to understand how the operator manages varying task demands in complex work environments.

Very preterm infants engage in an intervention to train their control of attention: results from the feasibility study of the Attention Control Training (ACT) randomised trial

BackgroundVery premature birth (gestational age between 28 and 31 + 6 weeks) is associated with increased risk of cognitive delay and attention deficit disorder, which have been linked to anomalies in the development of executive functions (EFs) and their precursors. In particular, very preterm (VP) infants display anomalies in controlling attention and gathering task-relevant information. Early interventions that support attention control may be pivotal in providing a secure base for VP children’s later attainments. The Attention Control Training (ACT) is a cognitive training intervention that targets infants’ abilities to select visual information according to varying task demands but had not been tested in VP infants. We conducted a feasibility study to test the processes we intend to use in a trial delivering the ACT to VP infants.Methods and designWe tested recruitment and retention of VP infants and their families in a randomised trial, as well as acceptability and completion of baseline and outcome measures. To evaluate these aims, we used descriptive quantitative statistics and qualitative methods to analyse feedback from infants’ caregivers. We also investigated the quality of eye-tracking data collected and indicators of infants’ engagement in the training, using descriptive statistics.ResultsTwelve VP infants were recruited, and 10 (83%) completed the study. Participants’ parents had high education attainment. The rate of completion of baseline and outcome measures was optimal. VP infants demonstrated engagement in the training, completing on average 84 min of training over three visits, and displaying improved performance during this training. Eye-tracking data quality was moderate, but this did not interfere with infants’ engagement in the training.DiscussionThe results suggest the ACT can be delivered to VP infants. However, challenges remain in recruitment of numerous and diverse samples. We discuss strategies to overcome these challenges informed by results of this study.Trial registrationRegistered Registration ID: NCT03896490. Retrospectively registered at Clinical Trials Protocol Registration and Results System (clinicaltrials.gov).

A novel single-leg squat test with speed and accuracy requirements: Reliability and validity in anterior cruciate ligament reconstructed individuals

BackgroundSome traditional single-leg squat tests focused on number of repetitions may not demand precise control of lower limb dynamic alignment, especially in the frontal and transverse planes. The primary objective of this study was to evaluate test–retest reliability and construct validity of a novel single-leg squat test – the ‘precision-squat test’ (PST) – designed to assess performance under varying task demands that can impact the execution of lower limb movements. A secondary objective was to investigate whether musculoskeletal factors predict performance in the PST in healthy individuals. MethodsThirty healthy participants were assessed to verify test–retest reliability. To verify the test’s construct validity, we compared the performance of 21 anterior cruciate ligament reconstructed (ACLR) individuals and 21 matched controls. Finally, 36 healthy individuals were assessed to verify the musculoskeletal factors related to PST performance. All participants performed the PST: they executed single-leg squats while moving a laser pointer (attached to the thigh) between two targets. We varied target size and distance between targets to manipulate the task difficulty. ResultsReliability of the PST was excellent at all demand levels (intraclass correlation coefficient (ICC)(3,2) > 0.93). Squat time increased under test conditions involving higher task difficulty (P < 0.001) and in ACLR individuals compared with age-matched controls (P < 0.05). Regression analyses revealed that reduced knee extensors and hip external rotators torques are related to increased squat time (P < 0.05). ConclusionsPST is a valid and reliable tool to assess performance of healthy and ACLR individuals. In addition, hip and knee strength are associated with performance during the test.

Trunk-pelvic coordination during unstable sitting with varying task demand: A methodological study

Unstable sitting is used commonly to evaluate trunk postural control (TPC), typically via measures based on center-of-pressure (CoP) time series. However, these measures do not directly reflect underlying control/movement strategies. We quantified trunk-pelvis coordination during unstable sitting using vector coding (VC) and correlated such coordination with CoP-based outcomes across varying task demands. Thirteen uninjured individuals (11 male/2 female) sat on an unstable chair at four instability levels, in a random order, defined relative to the individual gravitational gradient (∇G): 100, 75, 60, and 45%∇G. VC assessed trunk-pelvic coordination, and coupling angles classified movements as: 1) anti-phase, 2) in-phase, 3) trunk-phase, or 4) pelvic-phase. With decreasing %∇G (i.e., increasing instability), we found: increased anti-phase movement in the sagittal and frontal planes; decreased in-phase movement in the sagittal and frontal planes; and increased in-phase and pelvic-phase movement in the transverse plane. In the sagittal and frontal planes, we observed significant weak-to-moderate correlations between anti-phase and in-phase movements (0.288 < |ρ| < 0.549). Correlations between CoP-based measures and pelvic-phase and trunk-phase movements were typically weak and/or non-significant (|ρ| < 0.318). VC techniques discriminated between levels of instability during unstable sitting, identifying in-phase coordination (stiffening strategy) at lower instability levels and anti-phase coordination at higher instability levels. Compared to CoP-based measures, trunk coordination outcomes during unstable sitting provide measures of TPC that more directly quantify underlying movement strategies. These results can also serve as a baseline for future work investigating populations with impaired TPC (e.g., individuals with low back pain or limb loss).

Detecting Dynamic Community Structure in Functional Brain Networks Across Individuals: A Multilayer Approach.

We present a unified statistical framework for characterizing community structure of brain functional networks that captures variation across individuals and evolution over time. Existing methods for community detection focus only on single-subject analysis of dynamic networks; while recent extensions to multiple-subjects analysis are limited to static networks. To overcome these limitations, we propose a multi-subject, Markov-switching stochastic block model (MSS-SBM) to identify state-related changes in brain community organization over a group of individuals. We first formulate a multilayer extension of SBM to describe the time-dependent, multi-subject brain networks. We develop a novel procedure for fitting the multilayer SBM that builds on multislice modularity maximization which can uncover a common community partition of all layers (subjects) simultaneously. By augmenting with a dynamic Markov switching process, our proposed method is able to capture a set of distinct, recurring temporal states with respect to inter-community interactions over subjects and the change points between them. Simulation shows accurate community recovery and tracking of dynamic community regimes over multilayer networks by the MSS-SBM. Application to task fMRI reveals meaningful non-assortative brain community motifs, e.g., core-periphery structure at the group level, that are associated with language comprehension and motor functions suggesting their putative role in complex information integration. Our approach detected dynamic reconfiguration of modular connectivity elicited by varying task demands and identified unique profiles of intra and inter-community connectivity across different task conditions. The proposed multilayer network representation provides a principled way of detecting synchronous, dynamic modularity in brain networks across subjects.