Changes In Attentional Demands Research Articles

Neuroergonomic Attention Assessment in Safety-Critical Tasks: EEG Indices and Subjective Metrics Validation in a Novel Task-Embedded Reaction Time Paradigm

Background/Objectives: This study addresses the gap in methodological guidelines for neuroergonomic attention assessment in safety-critical tasks, focusing on validating EEG indices, including the engagement index (EI) and beta/alpha ratio, alongside subjective ratings. Methods: A novel task-embedded reaction time paradigm was developed to evaluate the sensitivity of these metrics to dynamic attentional demands in a more naturalistic multitasking context. By manipulating attention levels through varying secondary tasks in the NASA MATB-II task while maintaining a consistent primary reaction-time task, this study successfully demonstrated the effectiveness of the paradigm. Results: Results indicate that both the beta/alpha ratio and EI are sensitive to changes in attentional demands, with beta/alpha being more responsive to dynamic variations in attention, and EI reflecting more the overall effort required to sustain performance, especially in conditions where maintaining attention is challenging. Conclusions: The potential for predicting the attention lapses through integration of performance metrics, EEG measures, and subjective assessments was demonstrated, providing a more nuanced understanding of dynamic fluctuations of attention in multitasking scenarios, mimicking those in real-world safety-critical tasks. These findings provide a foundation for advancing methods to monitor attention fluctuations accurately and mitigate risks in critical scenarios, such as train-driving or automated vehicle operation, where maintaining a high attention level is crucial.

Uncharacteristic Task-Evoked Pupillary Responses Implicate Atypical Locus Ceruleus Activity in Autism.

Autism spectrum disorder (ASD) is characterized partly by atypical attentional engagement, reflected in exaggerated and variable responses to sensory stimuli. Attentional engagement is known to be regulated by the locus ceruleus (LC). Moderate baseline LC activity globally dampens neural responsivity and is associated with adaptive deployment and narrowing of attention to task-relevant stimuli. In contrast, increased baseline LC activity enhances neural responsivity across cortex and widening of attention to environmental stimuli regardless of their task relevance. Given attentional atypicalities in ASD, this study is the first to evaluate whether, under different attentional task demands, individuals with ASD exhibit a different profile of LC activity compared with typically developing controls. Males and females with ASD and age- and gender-matched controls participated in a one-back letter detection test while task-evoked pupillary responses, an established correlate for LC activity, were recorded. Participants completed this task in two conditions, either in the absence or presence of distractor auditory tones. Compared with controls, individuals with ASD evinced atypical pupillary responses in the presence versus absence of distractors. Notably, this atypical pupillary profile was evident despite the fact that both groups exhibited equivalent task performance. Moreover, between-group differences in pupillary responses were observed specifically in response to task-relevant events, providing confirmation that the group differences most likely were specifically associated with distinctions in LC activity. These findings suggest that individuals with ASD show atypical modulation of LC activity with changes in attentional demands, offering a possible mechanistic and neurobiological account for attentional atypicalities in ASD.SIGNIFICANCE STATEMENT Individuals with autism spectrum disorder (ASD) exhibit atypical attentional behaviors, including altered sensory responses and atypical fixedness, but the neural mechanism underlying these behaviors remains elusive. One candidate mechanism is atypical locus ceruleus (LC) activity, as the LC plays a critical role in attentional modulation. Specifically, LC activity is involved in regulating the trade-off between environmental exploration and focused attention. This study shows that, under tightly controlled conditions, task-evoked pupil responses, an LC activity proxy, are lower in individuals with ASD than in controls, but only in the presence of task-irrelevant stimuli. This suggests that individuals with ASD evince atypical modulation of LC activity in accordance with changes in attentional demands, offering a mechanistic account for attentional atypicalities in ASD.

Do postural constraints affect eye, head, and arm coordination?

If a whole body reaching task is produced when standing or adopting challenging postures, it is unclear whether changes in attentional demands or the sensorimotor integration necessary for balance control influence the interaction between visuomotor and postural components of the movement. Is gaze control prioritized by the central nervous system (CNS) to produce coordinated eye movements with the head and whole body regardless of movement context? Considering the coupled nature of visuomotor and whole body postural control during action, this study aimed to understand how changing equilibrium constraints (in the form of different postural configurations) influenced the initiation of eye, head, and arm movements. We quantified the eye-head metrics and segmental kinematics as participants executed either isolated gaze shifts or whole body reaching movements to visual targets. In total, four postural configurations were compared: seated, natural stance, with the feet together (narrow stance), or while balancing on a wooden beam. Contrary to our initial predictions, the lack of distinct changes in eye-head metrics; timing of eye, head, and arm movement initiation; and gaze accuracy, in spite of kinematic differences, suggests that the CNS integrates postural constraints into the control necessary to initiate gaze shifts. This may be achieved by adopting a whole body gaze strategy that allows for the successful completion of both gaze and reaching goals. NEW & NOTEWORTHY Differences in sequence of movement among the eye, head, and arm have been shown across various paradigms during reaching. Here we show that distinct changes in eye characteristics and movement sequence, coupled with stereotyped profiles of head and gaze movement, are not observed when adopting postures requiring changes to balance constraints. This suggests that a whole body gaze strategy is prioritized by the central nervous system with postural control subservient to gaze stability requirements.

The Effects of Changing Attention and Context in an Awake Offline Processing Period on Visual Long-Term Memory

There is accumulating evidence that sleep as well as awake offline processing is important for the transformation of new experiences into long-term memory (LTM). Yet much remains to be understood about how various cognitive factors influence the efficiency of awake offline processing. In the present study we investigated how changes in attention and context in the immediate period after exposure to new visual information influences LTM consolidation. After presentation of multiple naturalistic scenes within a working memory paradigm, recognition was assessed 30 min and 24 h later in three groups of subjects. One group of subjects engaged in a focused attention task [the Revised Attentional Network Task (R-ANT)] in the 30 min after exposure to the scenes. Another group of subjects remained in the testing room during the 30 min after scene exposure and engaged in no goal- or task-directed activities. A third group of subjects left the testing room and returned 30 min later. A signal detection analysis revealed no significant differences among the three groups in hits, false alarms, or sensitivity on the 30-min recognition task. At the 24-h recognition test, the group that performed the R-ANT made significantly fewer hits compared to the group that left the testing room and did not perform the attention ask. The group that performed the R-ANT and the group that remained in the testing room during the 30-min post-exposure interval made significantly fewer false alarms on the 24-h recognition test compared to the group that left the testing room. The group that stayed in the testing room and engaged in no goal- or task-directed activities exhibited significantly higher sensitivity (d′) compared to the group that left the testing room and the group that performed the R-ANT task. Staying in the same context after exposure to new information and resting quietly with minimal engagement of attention results in the best ability to distinguish old from novel visual stimuli after 24 h. These findings suggest that changes in attentional demands and context during an immediate post-exposure offline processing interval modulate visual memory consolidation in a subtle but significant manner.

Changes in Standing and Walking Performance Under Dual-Task Conditions Across the Lifespan.

Simultaneous performance of a postural and a concurrent task is rather unproblematic as long as the postural task is executed in an automatic way. However, in situations where postural control requires more central processing, cognitive resources may be exceeded by the addition of an attentionally demanding task. This may lead to interference between the two tasks, manifested in a decreased performance in one or both tasks (dual-task costs). Owing to changes in attentional demands of postural tasks as well as processing capacities across the lifespan, it might be assumed that dual-task costs are particularly pronounced in children and older adults probably leading to a U-shaped pattern for dual-task costs as a function of age. However, these changes in the ability of dual-tasking posture from childhood to old age have not yet been systematically reviewed. Therefore, Web of Science and PubMed databases were searched for studies comparing dual-task performance with one task being standing or walking in healthy groups of young adults and either children or older adults. Seventy-nine studies met inclusion criteria. For older adults, the expected increase in dual-task costs could be confirmed. In contrast, in children there was only feeble evidence for a trend towards enlarged dual-task costs. More good-quality studies comparing dual-task ability in children, young, and, ideally, also older adults within the same paradigm are needed to draw unambiguous conclusions about lifespan development of dual-task performance in postural tasks. There is evidence that, in older adults, dual-task performance can be improved by training. For the other age groups, these effects have yet to be investigated.

Priming to promote fluent motor skill execution: exploring attentional demands.

The effect of priming on the speed and accuracy of skilled performance and on a probe-reaction time task designed to measure residual attentional capacity, was assessed. Twenty-four skilled soccer players completed a dribbling task under three prime conditions (fluency, skill-focus, and neutral) and a control condition. Results revealed changes in trial completion time and secondary task performance in line with successfully priming autonomous and skill-focused attention. Retention test data for task completion time and probe-reaction time indicated a linear decrease in the priming effect such that the effect was nonsignificant after 30 min. Results provide further support for the efficacy of priming and provide the first evidence of concurrent changes in attentional demands, consistent with promoting or disrupting automatic skill execution.

Evaluation of Attentional Demands During Motor Learning: Validity of a Dual-Task Probe Paradigm

ABSTRACT The aim of this study was to examine the validity of a 2-choice audio-vocal reaction time (RT) probe task for measuring the changes in attentional demand during practice and learning of a discrete motor task. Twenty participants practiced the motor task across 3 days and were probed with the RT task during either the preparation or execution phase of the primary task. As practice progressed, participants improved in the primary task performance and shortened the RTs to the probe task. This indicated that less attention was required to plan and execute the movement and suggested that the RT probe task was a sensitive and valid tool to measure changes in attentional demands across practice. The authors implemented several additional experimental controls to address possible confounders including unintentional learning of the probe task, primary-secondary task trade-off effects, and compliance with task priority instructions. These experimental controls further ensured the validity of the probe paradigm and interpretability of the dual-task cost findings. Our experimental methods provided confirmatory evidence for the validity of the 2-choice RT task as a means to assess attentional demands during motor learning.

Attentional demands of cued walking in healthy young and elderly adults

Acoustic and visual cues are frequently used in gait rehabilitation. Attuning the steps to the cues is attentionally demanding. We examined the attentional demands of walking to two types of cues using a probe reaction time (RT) task. The steps were cued by either metronome beeps or visual stepping stones projected on a treadmill. The coupling between gait and these cues was assessed using a perturbation paradigm. In view of age-related changes in attentional demands of motor control, both elderly and young adults were tested. RTs were determined for walking to the two types of cues, as well as for three control conditions, viz. uncued walking, standing, and sitting. For all conditions, RTs were higher for elderly adults. However, the difference between elderly and young adults did not vary over conditions. Uncued walking required more attention than did standing and sitting. The attentional demands were further elevated during cued walking, with larger RTs for walking to visual stepping stones than to metronome beeps. Because the coupling to the cues was superior in the stepping stones condition, this type of cues seems to aid cued walking by allocating higher levels of attention to task-relevant information (viz. future footfall positions). Hence, the observed differences between the two cueing types may be associated with the natural dependence of gait on visual information.

Age Affects the Attentional Demands of Stair Ambulation: Evidence From a Dual-Task Approach

Approximately 75% of all injury-producing falls on steps for people of all ages occur in people 65 years of age and older. Diminished attentional capacity contributes to fall risk in older adults, particularly when task demands are high. The purpose of this study was to compare the attentional demands of ascending and descending a set of stairs (stair ambulation) in older adults and younger adults. This was a nonblinded, prospective, single-site, observational cohort study. Ten older (>65 years of age) and 10 younger (21-33 years of age) adults without disabilities were recruited. A dual-task approach was used for 2 task conditions: the first task was standing and responding verbally to an unanticipated auditory tone as quickly as possible (probe task), and the second task was ascending or descending a set of stairs with the same probe task. A 2-factor (group x task) analysis of variance with repeated measures on task (standing and stair ambulation) was performed for voice response time (VRT). Significance for the analysis was set at P<.05. The group x task interaction was significant for VRT. Post hoc analyses indicated that during stair ambulation, the VRT for older adults was significantly longer than that for younger adults. For the standing task, the VRTs (X+/-SD) were similar for younger (322+/-65 milliseconds) and older (306+/-22 milliseconds) participants. For stair ascent and descent, the average VRTs were more than 100 milliseconds longer for older participants (493+/-113 and 470+/-127 milliseconds, respectively) than for younger participants (365+/-56 and 356+/-67 milliseconds, respectively). Because of the small sample size and generally fit older group, generalization of findings to older people at risk for falls is not recommended until further research is done. The results demonstrated that although both older and younger adults required similar attentional resources for the standing task, older adults required significantly more resources during stair ambulation. The findings suggested that the dual-task method used here provided a clinically useful measure for detecting important changes in attentional demands in older adults who are healthy.

Declarative and Procedural Knowledge in Skill Acquisition: An Aptitude — Treatment Interaction Framework for Training

This paper focuses on the interactions among four constructs during skill acquisition: (1) the dynamic changes in attentional demands of the task to be acquired, (2) individual differences in cognitive and intellectual abilities, (3) conative (motivational), metacognitive processes involved in changes of attentional focus, and (4) knowledge structures acquired through part-task training. An attentional model is reviewed that describes how these variables interact during three phases of skill acquisition (i.e., during declarative knowledge, knowledge compilation, and at the level of proceduralized knowledge). Empirical demonstration of the framework is provided in the context of complex skill acquisition. Supportive results from a series of empirical studies are reviewed.

Neurological Pathophysiology

<b>Background:</b> Approximately 75% of all injury-producing falls on steps for people of all ages occur in people 65 years of age and older. Diminished attentional capacity contributes to fall risk in older adults, particularly when task demands are high. <b>Objective:</b> The purpose of this study was to compare the attentional demands of ascending and descending a set of stairs (stair ambulation) in older adults and younger adults. <b>Design:</b> This was a nonblinded, prospective, single-site, observational cohort study. <b>Methods:</b> Ten older (&gt;65 years of age) and 10 younger (21–33 years of age) adults without disabilities were recruited. A dual-task approach was used for 2 task conditions: the first task was standing and responding verbally to an unanticipated auditory tone as quickly as possible (probe task), and the second task was ascending or descending a set of stairs with the same probe task. A 2-factor (group × task) analysis of variance with repeated measures on task (standing and stair ambulation) was performed for voice response time (VRT). Significance for the analysis was set at <i>P</i>&lt;.05. <b>Results:</b> The group × task interaction was significant for VRT. <i>Post hoc</i> analyses indicated that during stair ambulation, the VRT for older adults was significantly longer than that for younger adults. For the standing task, the VRTs (X̄±SD) were similar for younger (322±65 milliseconds) and older (306±22 milliseconds) participants. For stair ascent and descent, the average VRTs were more than 100 milliseconds longer for older participants (493±113 and 470±127 milliseconds, respectively) than for younger participants (365±56 and 356±67 milliseconds, respectively). <b>Limitations:</b> Because of the small sample size and generally fit older group, generalization of findings to older people at risk for falls is not recommended until further research is done. <b>Conclusions:</b> The results demonstrated that although both older and younger adults required similar attentional resources for the standing task, older adults required significantly more resources during stair ambulation. The findings suggested that the dual-task method used here provided a clinically useful measure for detecting important changes in attentional demands in older adults who are healthy.