Decrements In Task Performance Research Articles

Did you even see that? visual sensory processing of single stimuli under different locomotor loads.

Modern living and working environments are more and more interspersed with the concurrent execution of locomotion and sensory processing, most often in the visual domain. Many job profiles involve the presentation of visual information while walking, for example in warehouse logistics work, where a worker has to manage walking to the correct aisle to pick up a package while being presented with visual information over data-glasses concerning the next order. Similar use-cases can be found in manufacturing jobs, for example in car montage assembly lines where next steps are presented via augmented reality headsets while walking at a slow pace. Considering the overall scarcity of cognitive resources available to be deployed to either the cognitive or motor processes, task performance decrements were found when increasing load in either domain. Interestingly, the walking motion also had beneficial effects on peripheral contrast detection and the inhibition of visual stream information. Taking these findings into account, we conducted a study that comprised the detection of single visual targets (Landolt Cs) within a broad range of the visual field (-40° to +40° visual angle) while either standing, walking, or walking with concurrent perturbations. We used questionnaire (NASA-TLX), behavioral (response times and accuracy), and neurophysiological data (ERPs and ERSPs) to quantify the effects of cognitive-motor interference. The study was conducted in a Gait Real-time Analysis Interactive Laboratory (GRAIL), using a 180° projection screen and a swayable and tiltable dual-belt treadmill. Questionnaire and behavioral measures showed common patterns. We found increasing subjective physical workload and behavioral decrements with increasing stimulus eccentricity and motor complexity. Electrophysiological results also indicated decrements in stimulus processing with higher stimulus eccentricity and movement complexity (P3, Theta), but highlighted a beneficial role when walking without perturbations and processing more peripheral stimuli regarding earlier sensory components (N1pc/N2pc, N2). These findings suggest that walking without impediments can enhance the visual processing of peripheral information and therefore help with perceiving non-foveal sensory content. Also, our results could help with re-evaluating previous findings in the context of cognitive-motor interference, as increased motor complexity might not always impede cognitive processing and performance.

Decreased automaticity contributes to dual task decrements in older compared to younger adults.

To contrast older and younger adults' prefrontal cortex (PFC) neural activity (through changes in oxygenated hemoglobin) during single and dual tasks, and to compare decrements in task performance. Changes in oxygenated hemoglobin of dorsolateral PFC were monitored using functional near-infrared spectroscopy during single tasks of spelling backwards (cognitive task) and 30m preferred paced walk; and a dual task combining both. Gait velocity was measured by a pressure sensitive mat. Twenty sex-matched younger (27.6 ± 3.5years) and 17 older adults (71.2 ± 4.9years) were recruited. The left PFC oxygenated hemoglobin decreased from start (1st quintile) to the end (5th quintile) of the walking task in younger adults ( - 0.03 ± 0.03 to - 0.72 ± 0.20µM; p < .05) unlike the non-significant change in older adults (0.03 ± 0.06 to - 0.41 ± 0.32µM, p > .05). Overall, oxygenation increased bilaterally during dual versus single walk task in older adults (Left PFC: 0.22 ± 0.16 vs. - 0.23 ± 0.21µM, respectively; Right PFC: 0.17 ± 0.18 vs. - 0.33 ± 0.22µM, respectively), but only in right PFC in younger adults ( - 0.02 ± 0.15 vs. - 0.47 ± 0.13µM). Older adults exhibited lower velocity during the dual task compared to younger adults (1.03 ± 0.16 vs. 1.20 ± 0.17m/s, respectively). Older age was associated with dual task cost on velocity during walking after adjusting for confounding variables. Age-related cognitive decline in older adults may increase neural activity for cognitive tasks and diminish walking automaticity that may lead to decrements during dual tasking; the greater PFC increases in the oxygenated hemoglobin and lower velocity may be due to increased cognitive load and limited attentional resources.

Narrative video scene description task discriminates between levels of cognitive impairment in Alzheimer's disease.

Because the ND task draws heavily on semantic and working memory ability in addition to basic visual perception, we aimed to assess the discriminative performance of this task across levels of cognitive impairment. We recruited 56 participants with cognitive status ranging from normal cognition to mild dementia (median age 82, range 66 to 99 years) to watch 20 30-s video clips and describe the visual content without time constraints. These verbal responses were transcribed and processed to generate ND shared word scores using a "wisdom of the crowd," natural-language processing approach. We compared ND scores across diagnostic groups, and used linear mixed models to examine decrements in task performance. There was a stepwise decline of ND scores with increasing levels of cognitive impairment. Additional analyses showed that ND performance was highly related to performance on the Montreal Cognitive Assessment (MoCA) and domain-specific neuropsychological tests for semantic fluency and set shifting. Other models demonstrated differences in ND performance related video content between cognitively normal and impaired participants. The ND test was able to detect decrements in task performance between levels of cognitive impairment and was related to other global neuropsychological measures. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Dual Task Effects on Visual Attention Capacity in Normal Aging.

Older adults show higher dual task performance decrements than younger adults. While this is assumed to be related to attentional capacity reductions, the precise affected functions are not specified. Such specification is, however, possible based on the “theory of visual attention” (TVA) which allows for modeling of distinct attentional capacity parameters. Furthermore, it is unclear whether older adults show qualitatively different attentional effects or whether they show the same effects as younger adults experience under more challenging conditions. By varying the complexity of the secondary task, it is possible to address this question. In our study, participants performed a verbal whole report of briefly presented letter arrays. TVA-based fitting of report performance delivered parameters of visual threshold t0, processing speed C, and visual short-term memory (VSTM) storage capacity K. Furthermore, participants performed a concurrent motor task consisting of continuous tapping of a (simple or complex) sequence. Both TVA and tapping tasks were performed under single and dual task conditions. Two groups of 30 younger adults each performed either the simple or complex tapping, and a group of 30 older adults performed the simple tapping condition. In older participants, VSTM storage capacity declined under dual task conditions. While no such effect was found in younger subjects performing the simple tapping sequence under dual task conditions, the younger group performing the complex tapping task under dual task conditions also showed a significant VSTM capacity reduction. Generally, no significant effect on other TVA parameters or on tapping accuracy was found. Comparable goodness-of-fit measures were obtained for the TVA modeling data in single and dual tasks, indicating that tasks were executed in a qualitatively similar, continuous manner, although quantitatively less efficiently under dual- compared to single-task conditions. Taken together, our results show that the age-specific effects of motor-cognitive dual task interference are reflected by a stronger decline of VSTM storage capacity. They support an interpretation of VSTM as central attentional capacity, which is shared across visual uptake and concurrent motor performance. Capacity limits are reached earlier, and already under lower motor task complexity, in older compared to younger adults.

The Grass Might Be Greener: Medical Marijuana Patients Exhibit Altered Brain Activity and Improved Executive Function after 3 Months of Treatment.

The vast majority of states have enacted full or partial medical marijuana (MMJ) programs, causing the number of patients seeking certification for MMJ use to increase dramatically in recent years. Despite increased use of MMJ across the nation, no studies thus far have examined the specific impact of MMJ on cognitive function and related brain activation. In the present study, MMJ patients seeking treatment for a variety of documented medical conditions were assessed prior to initiating MMJ treatment and after 3 months of treatment as part of a larger longitudinal study. In order to examine the effect of MMJ treatment on task-related brain activation, MMJ patients completed the Multi-Source Interference Test (MSIT) while undergoing functional magnetic resonance imaging (fMRI). We also collected data regarding conventional medication use, clinical state, and health-related measures at each visit. Following 3 months of treatment, MMJ patients demonstrated improved task performance accompanied by changes in brain activation patterns within the cingulate cortex and frontal regions. Interestingly, after MMJ treatment, brain activation patterns appeared more similar to those exhibited by healthy controls from previous studies than at pre-treatment, suggestive of a potential normalization of brain function relative to baseline. These findings suggest that MMJ use may result in different effects relative to recreational marijuana (MJ) use, as recreational consumers have been shown to exhibit decrements in task performance accompanied by altered brain activation. Moreover, patients in the current study also reported improvements in clinical state and health-related measures as well as notable decreases in prescription medication use, particularly opioids and benzodiapezines after 3 months of treatment. Further research is needed to clarify the specific neurobiologic impact, clinical efficacy, and unique effects of MMJ for a range of indications and how it compares to recreational MJ use.

Vigilance and Fatigue

Many everyday tasks, such as driving and reading technical reports, require sustained attention. These tasks may deplete attentional resources and/or lead to mind wandering, boredom and fatigue – cognitive states that result in impaired performance. Numerous competing theories exist to explain these performance decrements. In this panel, we will examine perspectives from both the fatigue and vigilance literatures, identifying points of common ground and differences in an attempt to further understand the underpinnings of performance decrements in tasks that require sustained attention. Experts in the interrelated yet frequently viewed as disparate areas of fatigue and vigilance are brought together to forge new theoretical ground.

Working memory, optimism and pain: An elusive link

In this issue of the Scandinavian Journal of Pain, Boselie and oworkers [1] report on evoked pain, positive reflection on selfmage, and how manipulation of these two factors could influence articipants’ performance on a working memory test. It is well ocumented that pain has a negative influence on working memry, but little is known about how we can counteract this effect. oselie and coworkers present data from two experimental studies n their article. The first study had a hypothesis about evoked pain aving a residual effect on working memory, and that optimism ould influence this effect. However, problems with demonstratng a residual effect from cold pressor pain on working memory ade thehypothesis difficult to test. The second study lookedat the nfluence optimistic self-reflection had on working memory perormance during heat induced pain. The results did, however, not upport the hypothesis of a protective effect of induced optimism n pain-related task performance decrements.

Contribution of binocular vision to the performance of complex manipulation tasks in 5–13 years old visually-normal children

Individual studies have shown that visuomotor coordination and aspects of binocular vision, such as stereoacuity and dynamic vergence control, continue to improve in normally developing children between birth and early teenage years. However, no study has systematically addressed the relationship between the development of binocular vision and fine manipulation skills. Thus, the aim of this cross-sectional study was to characterize performance of complex manipulation tasks during binocular and monocular viewing. Fifty-two children, between 5 and 13years old, performed 2 manipulation tasks: peg-board and bead-threading under randomized viewing conditions. Results showed that binocular viewing was associated with a significantly greater improvement in performance on the bead-threading task in comparison to the peg-board task and the youngest children showed the greatest decrement in task performance under the monocular viewing condition when performing the bead-threading task. Thus, the role of binocular vision in performance of fine manipulation skills is both task- and age-dependent. These findings have implications for assessment of visuomotor skills in children with abnormal binocular vision, which occurs in 2–3% of otherwise typically developing children.

Central adiposity and the functional magnetic resonance imaging response to cognitive challenge

BackgroundExcessive adipose tissue, particularly with a centralized distribution, propagates hormonal and metabolic disturbance. The detrimental effects of adiposity may extend beyond the periphery and target the central nervous system, increasing vulnerability to cognitive decline. The aim of current study was to determine how central adiposity impacts the brain at midlife by examining the blood oxygen level-dependent (BOLD) response to a challenging cognitive task.MethodsSeventy-three adults, aged 40-60 years, completed a 2-Back verbal working memory task during functional magnetic resonance imaging (fMRI). Central adiposity was assessed with waist circumference. The association between waist circumference and task-related activation in a priori regions of interest was modeled using bootstrapping regression models corrected for multiple-comparisons.ResultsLarger waist circumference was associated with diminished working-memory-related BOLD response in the right superior frontal gyrus (β=-0.008, p=0.001, 95% CI: -0.012 - -0.004) and left middle frontal gyrus (β=-0.009, p=0.002, 95% CI: -0.015 - -0.003), statistically adjusting for age, sex, systolic blood pressure, and total cholesterol. Reduced task-related activation in the right superior frontal gyrus (r=-0.369, p=0.002) and left middle frontal gyrus (r=-0.266, p=0.025) were related to slower reaction time on the task, controlling for age and education.ConclusionsLarger waist circumference predicted alterations in the BOLD response that coupled with decrements in task performance. While future studies are necessary, the results suggest that similar to its role in the periphery, central adiposity may be a robust predictor of metabolic and hormonal alterations that impinge upon central nervous system functioning.

The Effect of Continuous Wakefulness on Complex Cognitive Task Performance

In support of NASA’s modeling and simulation goals to predict the effects of operator fatigue on performance, research findings from the literature on the effect of acute sleep deprivation on performance of complex cognitive tasks were quantitatively synthesized. Regression models of performance over continuous hours of wakefulness demonstrated complex cognitive task performance decrements for both speed and accuracy, with the greater performance decrement on speed over continuous hours of wakefulness. Circadian effects were also examined and reveal a greater decrement to both speed and accuracy performance over continuous hours of wakefulness during the circadian night than circadian day.

Age, clutter, and competitive selection.

Modern theory explains visual selective attention as a competition for receptive fields in the extrastriate cortex. The present study examined whether this competition contributes to older adults' difficulty in processing visual clutter. In 2 experiments, young and older adult subjects made same-different judgments of target shapes in displays with or without clutter. The target shapes were either high or low in discriminability. The spatial separation between targets varied across trials, and the effects of competitive selection were gauged through decrements in task performance that resulted as separation decreased. Both age groups showed a competition-in-clutter effect, evincing a stronger influence of target separation within cluttered displays. However, the costs of clutter in general and the strength of the competition-in-clutter effect more specifically were both substantially larger for older adults. Effects of clutter and competition also varied with stimulus discriminability; judgments of highly discriminable stimuli evinced no intertarget competition in uncluttered displays for either age group, while judgments of less discriminable stimuli showed competition whether clutter was present or not. Results suggest that clutter disproportionately degrades older adults' visual performance by forcing more careful stimulus resolution, engendering stronger competition for selection.

The Harder the Task, the More Inconsistent the Performance: A PPT Analysis on Task Difficulty

ABSTRACT Previous research has demonstrated that as task difficulty increases, task performance subsequently decreases. These decrements in task performance as difficulty increases have been attributed to the processes individuals use to complete tasks. Over a series of three experiments, Potential Performance Theory (PPT; Trafimow & Rice, 2008; 2009), was used to test the hypothesis that decreases in task performance are, in part, due to inconsistency rather than only systematic factors. Task difficulty was manipulated in three visual search tasks by increasing set size (Experiment 1), decreasing contrast (Experiment 2), and increasing background distracters (Experiment 3). Findings over the three studies indicated that decreases in observed task performance as task difficulty increases are primarily due to a decrease of consistency rather than systematic factors. The theoretical implications of these findings are discussed.

Impact of Monetary Incentives on Cognitive Performance and Error Monitoring following Sleep Deprivation

To examine whether monetary incentives attenuate the negative effects of sleep deprivation on cognitive performance in a flanker task that requires higher-level cognitive-control processes, including error monitoring. Twenty-four healthy adults aged 18 to 23 years were randomly divided into 2 subject groups: one received and the other did not receive monetary incentives for performance accuracy. Both subject groups performed a flanker task and underwent electroencephalographic recordings for event-related brain potentials after normal sleep and after 1 night of total sleep deprivation in a within-subject, counterbalanced, repeated-measures study design. Monetary incentives significantly enhanced the response accuracy and reaction time variability under both normal sleep and sleep-deprived conditions, and they reduced the effects of sleep deprivation on the subjective effort level, the amplitude of the error-related negativity (an error-related event-related potential component), and the latency of the P300 (an event-related potential variable related to attention processes). However, monetary incentives could not attenuate the effects of sleep deprivation on any measures of behavior performance, such as the response accuracy, reaction time variability, or posterror accuracy adjustments; nor could they reduce the effects of sleep deprivation on the amplitude of the Pe, another error-related event-related potential component. This study shows that motivation incentives selectively reduce the effects of total sleep deprivation on some brain activities, but they cannot attenuate the effects of sleep deprivation on performance decrements in tasks that require high-level cognitive-control processes. Thus, monetary incentives and sleep deprivation may act through both common and different mechanisms to affect cognitive performance.

Alterations in attentional mechanisms in response to acute inflammatory pain and morphine administration

Research indicates that pain negatively impacts attention; however, the extent of this impact and the mechanisms of the effect of pain on normal attentional processing remain unclear. This study 1) examined the impact of acute inflammatory pain on attentional processing, 2) examined the impact of morphine on attentional processing, and 3) determined if an analgesic dose of morphine would return attentional processing to normal levels. Male Sprague–Dawley rats were trained on the 5 choice serial reaction time task (5CSRTT), a test commonly used to assess the attentional mechanisms of rodents. Animals were injected with saline or 1, 3, or 6 mg/kg of morphine. Twenty minutes later, animals received a formalin (or saline) injection into one hind paw to induce an inflammatory condition and were then immediately tested in the 5CSRTT. The results show that the formalin injection significantly impaired performance, as measured by an increase in the number of trials in which the animal failed to attend to the task. Likewise, a high dose of morphine (6 mg/kg) produced similar decrements in task performance. Of primary importance is that 3 mg/kg of morphine produced analgesia with only mild sedation, and performance in the 5CSRTT was improved with this dose. This is the first study to use an animal model of acute pain to demonstrate the negative impact of pain on attention, and provides a novel approach to examine the neural correlates that underlie the disruptive impact of pain on attention.

Postural costs of performing cognitive tasks in non-coincident reference frames

Dual-task interactions in posture and cognitive tasks have been explained as a competition for spatial processing structures or as interference in the online sensorimotor adjustments required for sensory integration. Going beyond these general terms accounts, we propose that interference between spatial and temporal operations in posture-cognition arises at least partly from the need to share a common behavioral context, such as a spatial frame of reference. Using immersive visualization and motion-tracking techniques, we manipulated the spatial reference frames for a standing task and a conjunction visual search task into or out of coincidence. Aside from performance trade-offs due to task-load manipulations, performing visual search in a non-coincident reference frame led to cognitive task and postural task performance decrements (Experiment 1). Postural dual-task decrements were also observed when visual search was split between coincident and non-coincident frames and both frame conditions rendered identical in visual information relevant to posture control (Experiment 2). We concluded that the postural control costs observed for posture-cognition dual-tasking may in part reflect costs of keeping tasks' reference frames in register.

Increasing Self-Regulatory Strength Can Reduce the Depleting Effect of Suppressing Stereotypes

Three longitudinal studies and one correlational study tested the hypothesis that increasing self-regulatory strength by regular self-regulatory exercise would reduce the intrapsychic costs of suppressing stereotypes. Participants tried to resist using stereotypes while describing or talking to a stimulus person. Participants whose habitual motivation to suppress stereotypes was low exhibited impaired Stroop and anagram performance after the suppression task, presumably because of self-regulatory depletion (i.e., a reduction of self-regulatory strength following prior use). Two weeks of self-regulation exercises (such as using one's nondominant hand or refraining from cursing) eliminated this effect. These findings indicate that self-regulatory exercise can improve resistance to self-regulatory depletion and, consequently, people can suppress stereotypes without suffering subsequent decrements in task performance.

A non‐invasive method for studying an index of pupil diameter and visual performance in the rhesus monkey

A non-invasive model has been developed to estimate gaze direction and relative pupil diameter, in minimally restrained rhesus monkeys, to investigate the effects of low doses of ocularly administered cholinergic compounds on visual performance. Animals were trained to co-operate with a novel device, which enabled eye movements to be recorded using modified human eye-tracking equipment, and to perform a task which determined visual threshold contrast. Responses were made by gaze transfer under twilight conditions. 4% w/v pilocarpine nitrate was studied to demonstrate the suitability of the model. Pilocarpine induced marked miosis for >3 h which was accompanied by a decrement in task performance. The method obviates the need for invasive surgery and, as the position of point of gaze can be approximately defined, the approach may have utility in other areas of research involving non-human primates.

Observational Analysis of Video Records of Team Performance

Observation is a traditional ethnographic approach for data collection in real dynamic workplaces. Video recording of brief, risky, but beneficial tasks was investigated for use as an enhancement of observation to assess team performance. Audio-video recording took place in a trauma center using cameras attached to the ceiling of resuscitation bays. Chest tube insertion, a task with an easily defined start and finish time, was video recorded at two levels of urgency. An expert defined task analysis was determined by interview and questionnaires and was used to identify performance problems and opportunities for task improvement. The findings were that video recording has important advantages over observation as a reusable record to extract qualitative and quantitative data. However, observation is easier, less time consuming and a less quantitable data collection tool. Particular benefits of video were the fine-grained analyses of second by second behavioral and verbal interactions and events or tasks not noted by the care providers at the time. A task analysis template was useful used to aggregate findings across multiple task accomplishments and identified task performance decrements with increased urgency. Video data contributed to identification of latent system failures and ergonomic issues that were often central to interpretation and causal hypothesis development surrounding performance problems. Video is a powerful feedback and training tool that can be used to obtain ‘buy in’ from care providers for change. Video-derived performance measures can define and be used to promote best practice performance in dynamic risky and complex medical workplaces.

Mental models – reaching in the dark?

Exploring the nature of our mental representations has been an important theme in cognitive science. Within developmental psychology, there is an ongoing debate about when infants develop the ability to create proper mental representations. McCall and Clifton1xInfants’ means-end search for hidden objects in the absence of visual feedback. McCall, D.D. and Clifton, R.K. Infant Behav. Dev. 1999; 22: 179–195Crossref | Scopus (13)See all References1 investigated this issue using a reaching-in-the-dark procedure based on previous work from their laboratory. In this experiment, eight-month-old infants saw (with the room lights on) an object placed behind a door. Then the lights went out and the infants’ behavior was monitored with an infra-red camera. The babies could still localize the object in the dark from a sound cue, as it made a rattling sound. Behavior on these dark trials was compared with the infants’ behavior when the lights stayed on. The important questions were, would infants reach for the object in the dark, and if so, how would their reaching behavior differ from reaching in the light? Formally, the task was a rather difficult one: infants had to engage in ‘means-end planning’ (i.e. opening the door to get the object) from memory. In the dark trials, infants could not use their visual perception of the world to achieve the end – they had to use some kind of mental representation to complete the task. Results showed an overall decrement in task performance from light to dark trials, although infants made a substantial amount of reaching in the dark. Moreover, the dark reaching was qualitatively the same as the light reaching in terms of accuracy of reach, number of reaches, and the latency of reaches. These data support the idea that infants as young as eight months are capable of creating mental representations substantial enough to support a reasoning chain without the benefit of visual feedback. Further research of this sort should provide more detail about the development of mental models in infancy.

Nitric Oxide Synthase Inhibition Impairs Delayed Recall in Mature Monkeys

The gaseous neuromodulator nitric oxide (NO) is formed in brain regions known to mediate learning and memory processes. In rodent models, pharmacologic inhibition of NO synthesis impairs such processes. In the present study, N ω-nitro- l-arginine methyl ester ( l-Name), an inhibitor of the constituitive form of the NO synthetic enzyme, was administered to seven non-aged, mature monkeys ( Macaca Fascicularis, Macaca Mulatta, and Macaca Nemestrima) trained to perform a delayed matching-to-sample task (DMTS). l-Name (1,5, 25, and 50 mg/kg) produced marked decrements in task performance, as well as a reduction in the number of trials completed at the highest dose. This impairment of DMTS accuracy by the 50 mg/kg doses of l-Name appears to be associated with an aversive state marked by gastrointestinal disturbance and lethargy. The detrimental effects of the 25 mg/kg dose of l-Name on DMTS accuracy were completely blocked by concurrent administration of a mole-equivalent dose of the NO amino acid precursor l-arginine. As a whole, these data suggest that l-Name impairs processes involved in delayed recall in monkeys and that this impairment is associated with attenuated synthesis of NO. However, at higher doses (⩾ 25 mg/kg) this impairment is associated with aversive effects of l-Name, possibly at both central and peripheral sites.