Volitional Running and Tone Counting: The Impact of Cognitive Load on Running Over Natural Terrain

Swimming with a head-mounted display: dual-task costs

Head-up displays (HUDs) have the potential to change work in operation environments by providing hands-free information to wearers. However, these benefits may be accompanied by trade-offs, primarily by increasing cognitive load due to dividing attention. Previous studies have attempted to understand the trade-offs of HUD usage; however, all of which were focused on land-based tasks. A gap in understanding exists when examining HUD use in aquatic environments as immersion introduces unique environmental and physiological factors that could affect multitasking. In this study, we investigated multitasking performance associated with swimming with a HUD. Eighteen participants completed three tasks: swimming only, a HUD-administered word recall task, and a dual-task combining both tasks. Results revealed significant dual-task interference in both tasks, though possibly less pronounced than in land-based tasks. These findings enhance not only help characterise dual-task performance, but also offer valuable insights for HUD design for aquatic settings.

Response uncertainty influences response bias in the sustained attention to response task: a signal detection theory perspective

In the current investigation, we modified the high Go, low No-Go Sustained Attention to Response Task (SART) by replacing the single response on Go trials with a dual response to increase response uncertainty. In three experiments, a total of 80 participants completed either the original SART with no response uncertainty regarding the Go stimuli, or versions of the dual response SART in which response probabilities for the two possible responses to the Go stimuli varied from 0.9-0.1, 0.7-0.3, to 0.5-0.5. This resulted in a scale of increasing response uncertainty based on information theory to the Go stimuli. The probability of No-Go withhold stimuli was kept.11 in all experiments. Using the Signal Detection Theory perspective proposed by Bedi et al. (Psychological Research: 1-10, 2022), we predicted that increasing response uncertainty would result in a conservative response bias shift, noted by decreased errors of commission and slower response times to both Go and No-Go stimuli. These predictions were verified. The errors of commission in the SART may not be a measures of conscious awareness per se, but instead indicative of the level of participant trigger happiness-the willingness to respond quickly.

Mind over body: Interfering with the inner voice is detrimental to endurance performance

In two preregistered experiments, we investigated whether covert language is involved in sustained physical efforts, specifically if people are less able to push themselves physically when distracted from using inner speech. In both experiments, participants performed 12 cycling trials (Experiment 1: N = 49; Experiment 2: N = 50), each lasting 1 min where participants were required to cycle as fast as possible while simultaneously engaging in either a visuospatial task, a verbal task or no interference. Experiment 1: Participants performed worse in the verbal interference condition compared with the control condition (d = 0.29) and verbal interference performance was numerically but not significantly worse than visuospatial interference (d = 0.22). Experiment 2: A more demanding interference task yielded significant slower cycling with verbal interference compared to both control (d = 1) and visuospatial interference (d = 0.43). These results indicate that inner speech plays a causal role in control of sustained physical efforts.

Assessing Cognitive-Motor Interference in Military Contexts: Validity and Reliability of Two Dual-tasking Tests

INTRODUCTION

Cognitive-motor interference is the decrease in cognitive performance and/or physical performance occurring when a cognitive task and a physical task are performed concurrently (dual task) compared to when they are performed in isolation (single task). The aim of this study was to investigate the construct validity and test-retest reliability of two cognitive-motor interference tests in military contexts.

MATERIALS AND METHODS

Twenty-two soldiers, officers, and cadets performed a 10-min loaded marching, a 10-min Psychomotor Vigilance Task, and the two tasks combined (visit 1). During visit 2, a 5-min running time trial, a 5-min Word Recall Task, and the two tasks combined. These tests were repeated by 20 participants after 2 weeks (visits 3 and 4).

RESULTS

Significant impairments were shown on both running distance (P < .001) and number of words recalled (P = .004) in the dual-task condition compared to the single-task condition. Significantly shorter step length (P < .001) and higher step frequency (P < .001) were found during the loaded marching in the dual-task condition compared to the single-task condition. No significant differences were observed in mean reaction time (P = .402) and number of lapses (P = .479) during the Psychomotor Vigilance Task. Good-to-excellent reliability was found for all the cognitive and physical variables in both single- and dual-task conditions, except for the number of lapses.

CONCLUSION

These findings suggest that the Running + Word Recall Task test is a valid and reliable dual-tasking test that could be used to assess cognitive-motor interference in military contexts.

Task-related and task-unrelated thoughts in runners and equestrians: Measurement issues in evaluations of thought content

Much of the thought content and mind-wandering literature examines self-reported thought content's relationship with performance criteria in limited ways. Furthermore, retrospective reports about thought content may be influenced by the quality of one's performance. We explored these method issues in a cross-sectional study of individuals competing in a trail race and an equestrian event. Our results demonstrated that self-reports of thought content differed based on the performance context: whereas runners' task-related and task-unrelated thoughts were negatively correlated, equestrians' thought content showed no relationship. Moreover, equestrians in general reported fewer task-related and task-unrelated thoughts than runners. Finally, objective performance predicted task-unrelated thought (but not task-related thought) among runners, and an exploratory mediation test suggested the effect was partially mediated by performance awareness. We discuss the applied implications of this research for human performance practitioners.

Dual-task effects between tone counting and mathematical calculations

We examined the impact of performing a tone counting task of varying cognitive loads and mathematical calculations simultaneously, compared to performance on the same tasks done individually. Participants performed continuous mathematical calculations, performed a high and a low cognitive load tone counting task, and also performed the math and counting tasks simultaneously. Performing the two tasks together resulted in significant dual-task interference. We also compared these results to previous studies employing the tone counting tasks with physically demanding tasks (climbing, kayaking and running). The interference between tone counting and mathematical calculations was worse than the interference between tone counting and running and kayaking. For climbing, the difference in interference was more nuanced with evidence indicating climbing uniquely asserts task prioritization. These findings have implications for operations requiring dual or multi-tasking.

Evaluating the dual-task decrement within a simulated environment: Word recall and visual search

Simulated environments have become better able to replicate the real world and can be used for a variety of purposes, such as testing new technology without any of the costs or risks associated with working in the real world. Because of this, it is now possible to gain a better understanding of cognitive demands when working in operational environments, where individuals are often required to multitask. Multitasking often results in performance decrements, where adding more tasks can cause a decrease in performance in each of the individual tasks. However, little research investigated multitasking performance in simulated environments. In the current study we examined how multitasking affects performance in simulated environments. Forty-eight participants performed a dual visual search and word memory task where participants were navigated through a simulated environment while being presented with words. Performance was then compared to single-task performance (visual search and word memory alone). Results showed that participants experienced significant dual-task interference when comparing the dual-tasks to the single-tasks and subjective measures confirmed these findings. These results could provide useful insight for the design of technology in operational environments, but also serve as an evaluation of MRT in simulated environments.

The effects of dual-task interference on visual search and verbal memory

The operational costs of multitasking are more pressing given the increase in wearable technologies (head-up displays; HUDs) that facilitate multitasking. Often multitasking comes with performance costs, where the addition of more tasks impairs the performance of the tasks. The current study explored the extent to which multitasking interference can be characterised in simulated environments, as opposed to risky and harsh environments in real operational contexts. Forty-eight participants completed several trials where they performed a visual search task while navigating a simulated environment. There were three conditions: a standalone memory task, a standalone search task, and both tasks simultaneously. Results revealed significant dual-task interference when comparing the dual-task to each of the single-tasks. Results were corroborated by subjective workload and stress metrics. The results could prove useful for designing systems for individuals who routinely multitask in operational environments. Specifically, by furthering the understanding of their performance capabilities and trade-offs due to multitasking.Practitioner summary: Due to the demands of multitasking in operational environments, quantifying the degree of information lost on each task individually will aid in the understanding of the deficits of multitasking performance. This study shows that deficits in multi-tasking (via a HUD) can be understood in simulated environments to a similar degree as real-world tasks.

The impact of cognitive load on kayaking and kayaking on cognitive performance

OBJECTIVE

We examined the impact of performing a cognitive task of varying loads and kayaking simultaneously, compared to performance on the same tasks individually.

BACKGROUND

When two tasks are performed together, performance often suffers compared to performance on either task alone. Interference not only occurs in competing cognitive tasks, but has also been found with certain physically demanding activities, such as climbing.

METHOD

Skilled kayakers performed a kayak course on open water, performed a high and a low cognitive load tone counting task, and also performed the kayak and counting tasks simultaneously.

RESULTS

Despite some past research finding dual task facilitation with laboratory aerobic activities, simultaneous kayaking and tone counting led to dual-task interference.

CONCLUSION

Concurrent counting and kayaking led to performance impairments in both tasks, relative to single task performance.

APPLICATION

The present results are applicable to occupations involving concurrent demanding physical activity and cognitive task performance, such as the work of first responders and military operators. PRéCIS: Kayaking, like climbing, appears to hinder cognitive performance more than the low-risk physical tasks carried out in laboratory conditions.

Dual-task interference while receiving information on a head mounted display and manual tracking with and without auditory warnings

BACKGROUND

Dual-task interference is a concern when users attempt to use head mounted displays (HMD) while performing seated manual control tasks. Auditory warnings of information displayed on the HMD may or may not assist users while multi-tasking.

OBJECTIVE

In this study, we investigated the dual-task interference of words, to be remembered later, presented on a HMD and motor control in a manual tracking task. The word presentations were warned or not warned with auditory signals and the impact of audio warnings were examined.

METHODS

Participants were required to perform five tasks: (1) a compensatory tracking task performed alone, (2) a word memory task performed alone, (3) a tracking and word memory task, (4) a word memory task with words preceded by audial signals, and (5) a tracking and word memory task with words preceded by audial signals. In addition, in the dual-tasks, half of the word presentations were paired with directions changes in the tracking task to test for immediate perceptual interference.

RESULTS

There were significant dual task costs for both mean tracking error and later word recall. Additionally, participants took significantly longer to respond to motion changes paired with word presentations than motion changes not paired with word presentations. However, the impact of auditory warnings on tracking performance was nuanced.

CONCLUSION

Even with an in field of view transparent HMD momentary and sustained cognitive dual-task interference remains. Reaction times are affected most in the worst case scenario, when task critical events occur at the same time as a text message.

APPLICATION

The use of HMDs in time critical manual control tasks (such as operating machinery) should be limited. The use of audial warnings to alert operators to information displayed on an HMD requires further research; it may disrupt appropriate or natural task ordering.

A Framework to Explore Proximate Human-Robot Coordination

Proximate human-robot teaming (pxHRT) is a complex subspace within human-robot interaction. Studies in this space involve a range of equipment and methods, including the ability to sense people and robots precisely. Research in this area draws from a wide variety of other fields, from human-human interaction to control theory, making study design complex, particularly for those outside the field of HRI. In this paper, we introduce a framework that helps researchers consider tradeoffs across various task contexts, platforms, sensors, and analysis methods; metrics frequently used in the field; and common challenges researchers may face. We demonstrate the use of the framework via a case study which employs an autonomous mobile manipulator continuously engaging in shared workspace, handover, and co-manipulation tasks with people, and explores the effect of cognitive workload on pxHRT dynamics. We also demonstrate the utility of the framework in a case study with two groups of researchers new to pxHRT. With this framework, we hope to enable researchers, especially those outside HRI, to more thoroughly consider these complex components within their studies, more easily design experiments, and more fully explore research questions within the space of pxHRT.

The impact of cognitive load on climbing and climbing on cognitive performance

OBJECTIVE

We examined the impact of increasing cognitive load on climbing performance and the impact of climbing on concurrent cognitive task performance.

BACKGROUND

Generally when two tasks are performed simultaneously performance of one or both suffers relative to performance of each alone. Such dual task decrement is not confined to competing cognitive tasks, but has also been found when one task involves demanding physical activity.

METHOD

Skilled climbers performed a traverse climb alone and in combination with low and high cognitive load counting tasks, which were also performed alone.

RESULTS

In more realistic physical settings, physical and cognitive tasks will interfere, unlike what some literature using laboratory physical tasks may indicate.

CONCLUSION

Compared to single task (climb only) performance concurrent counting and climbing resulted in impaired performance. However, climbers appeared to prioritize climbing over cognitive task performance.

APPLICATION

The results and this program of research have implications for occupations that involve concurrent demanding physical activity and cognitive task performance. PRéCIS: High risk, physical tasks in real world conditions appear to hinder cognitive performance more so than low-risk physical tasks carried out in laboratory conditions.

Dual-Task Interference Between Swimming and Verbal Memory

OBJECTIVE

A dual-task study was performed to explore the performance effects for swimming, word recall, and the combination of the two tasks performed simultaneously.

BACKGROUND

Dual-task interference studies have been performed for a variety of tasks; however, there has not been much dual-task interference research where one of the tasks is a naturalistic physically strenuous task. Swimming is a unique physical task that requires spatial orientation on three dimensional axes, similar to that of flying, but has no risk of falling. Previous studies have been conducted in other activity combinations with word-free recall, such as running and climbing, but swimming has yet to be explored.

METHOD

A verbal memory recall task and swimming task were performed in isolated (single-task) and simultaneous conditions. A comparison of effects across these different activities was also explored.

RESULTS

Swimming and the word-recall task resulted in significant dual-task interference: almost as much as when word recall was paired with another verbal task, but more than running and less than climbing.

CONCLUSION

Consistent with other dual-task studies, this study observed dual-task interference between the physical swimming task and the cognitive verbal memory task.

APPLICATION

Future technologies and training for personnel who engage in water rescue or commercial diving, such as underwater welding and fiber optic cable, may be improved by these findings.

No evidence of the effect of cognitive load on self-paced cycling performance

Objectives

To test the hypothesis that cognitive load (low vs. high load) during a 20 min self-paced cycling exercise affects physical performance.

Design

A pre-registered (https://osf.io/qept5/), randomized, within-subject design experiment.

Methods

28 trained and experienced male cyclists completed a 20 min self-paced cycling time-trial exercise in two separate sessions, corresponding to two working memory load conditions: 1-back or 2-back. We measured power output, heart rate, RPE and mental fatigue.

Results

Bayes analyses revealed extreme evidence for the 2-back task being more demanding than the 1-back task, both in terms of accuracy (BF₁₀ = 4490) and reaction time (BF = 1316). The data only showed anecdotal evidence for the alternative hypothesis for the power output (BF₁₀ = 1.52), moderate evidence for the null hypothesis for the heart rate (BF₁₀ = 0.172), anecdotal evidence for RPE (BF₁₀ = 0.72) and anecdotal evidence for mental fatigue (BF₁₀ = 0.588).

Conclusions

Our data seem to challenge the idea that self-paced exercise is regulated by top-down processing, given that we did not show clear evidence of exercise impairment (at the physical, physiological and subjective levels) in the high cognitive load condition task with respect to the low working memory load condition. The involvement of top-down processing in self-pacing the physical effort, however, cannot be totally discarded. Factors like the duration of the physical and cognitive tasks, the potential influence of dual-tasking, and the participants’ level of expertise, should be taken into account in future attempts to investigate the role of top-down processing in self-paced exercise.

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.

Dual-task Interference: Swimming and Verbal Free Recall

Dual-task interference studies have been performed using a variety of different tasks, however, there has been limited research examining dual-tasks interference where one of the tasks is an ecologically realistic physically demanding task. Swimming is a task that involves three spatial axes, similar to flying, but is also physically demanding for the entire body as all four limbs are used to propel the swimmer through the water. A dual-task case study was conducted to compare repeated performance in a swimming task, a verbal free recall task and a dual-task where swimming and free recall were combined. While previous research has examined running and climbing when combined with the verbal free recall task, these studies were one-off studies, whereas the present study was conducted longitudinally with repeated sessions. The current study was performed in a single individual across several weeks to investigate the longitudinal change of dual-task interference.

Prefrontal Hemodynamics of Physical Activity and Environmental Complexity During Cognitive Work

OBJECTIVE

The aim of this study was to assess performance and cognitive states during cognitive work in the presence of physical work and in natural settings.

BACKGROUND

Authors of previous studies have examined the interaction between cognitive and physical work, finding performance decrements in working memory. Neuroimaging has revealed increases and decreases in prefrontal oxygenated hemoglobin during the interaction of cognitive and physical work. The effect of environment on cognitive-physical dual tasking has not been previously considered.

METHOD

Thirteen participants were monitored with wireless functional near-infrared spectroscopy (fNIRS) as they performed an auditory 1-back task while sitting, walking indoors, and walking outdoors.

RESULTS

Relative to sitting and walking indoors, auditory working memory performance declined when participants were walking outdoors. Sitting during the auditory 1-back task increased oxygenated hemoglobin and decreased deoxygenated hemoglobin in bilateral prefrontal cortex. Walking reduced the total hemoglobin available to bilateral prefrontal cortex. An increase in environmental complexity reduced oxygenated hemoglobin and increased deoxygenated hemoglobin in bilateral prefrontal cortex.

CONCLUSION

Wireless fNIRS is capable of monitoring cognitive states in naturalistic environments. Selective attention and physical work compete with executive processing. During executive processing loading of selective attention and physical work results in deactivation of bilateral prefrontal cortex and degraded working memory performance, indicating that physical work and concomitant selective attention may supersede executive processing in the distribution of mental resources.

APPLICATION

This research informs decision-making procedures in work where working memory, physical activity, and attention interact. Where working memory is paramount, precautions should be taken to eliminate competition from physical work and selective attention.

Rest Is Still Best

OBJECTIVE

We examined the impact task interruptions of differing qualitative and quantitative load have on visuospatial vigilance sensitivity.

BACKGROUND

The vigilance decrement and attempts to develop countermeasures to the decrement is one of the most important human factors issues. There is an ongoing debate between those who interpret the increase in the rate of failures to detect signals over time as being due to objective task monotony or task underload and those who interpret this increased failure proneness as being predominately due to cognitive-resource depletion and task overload.

METHOD

Participants were assigned at random to one of six interruptions: Participants were given a complete rest (rest); participants completed a 1-back verbal working-memory (WM) task, a 3-back verbal WM task, a 1-back spatial WM task, or a 3-back spatial WM task; or participants performed the primary vigilance task (continuous).

RESULTS

Postinterruption performance was best for rest and worst for continuous. A resource theory perspective led us to make two possible predictions of relative interruption effect orders of the six conditions out of 720 possible orderings. We found one of the two orders.

CONCLUSION

Overall, the vigilance sensitivity decrement appears to be due to the recurring use of particular cognitive resources, and resource theorists should explore this more extensively in the future.

APPLICATION

Countermeasures for the vigilance decrement should be based on clear cognitive-resource considerations. Rest is the best countermeasure. Intervening tasks should be chosen that minimize resource-demand overlap with the vigilance task.

Transforming Life: A Broad View of the Developmental Origins of Health and Disease Concept from an Ecological Justice Perspective

The influential scientist Rene J. Dubos (1901–1982) conducted groundbreaking studies concerning early-life environmental exposures (e.g., diet, social interactions, commensal microbiota, housing conditions) and adult disease. However, Dubos looked beyond the scientific focus on disease, arguing that “mere survival is not enough”. He defined mental health as fulfilling human potential, and expressed concerns about urbanization occurring in tandem with disappearing access to natural environments (and elements found within them); thus modernity could interfere with health via “missing exposures”. With the advantage of emerging research involving green space, the microbiome, biodiversity and positive psychology, we discuss ecological justice in the dysbiosphere and the forces—financial inequity, voids in public policy, marketing and otherwise—that interfere with the fundamental rights of children to thrive in a healthy urban ecosystem and learn respect for the natural environment. We emphasize health within the developmental origins of health and disease (DOHaD) rubric and suggest that greater focus on positive exposures might uncover mechanisms of resiliency that contribute to maximizing human potential. We will entrain our perspective to socioeconomic disadvantage in developed nations and what we have described as “grey space”; this is a mental as much as a physical environment, a space that serves to insidiously reinforce unhealthy behavior, compromise positive psychological outlook and, ultimately, trans-generational health. It is a dwelling place that cannot be fixed with encephalobiotics or the drug-class known as psychobiotics.