Interstimulus Intervals and Sensory Modality Modulate the Impact of a Cognitive Task on Postural Control

2016 ◽  
Vol 48 (6) ◽  
pp. 482-488 ◽  
Author(s):  
Nadia Polskaia ◽  
Yves Lajoie
Author(s):  
Kristy Martin ◽  
Emily McLeod ◽  
Julien Périard ◽  
Ben Rattray ◽  
Richard Keegan ◽  
...  

Objective: In this review, we detail the impact of environmental stress on cognitive and military task performance and highlight any individual characteristics or interventions which may mitigate any negative effect. Background: Military personnel are often deployed in regions markedly different from their own, experiencing hot days, cold nights, and trips both above and below sea level. In spite of these stressors, high-level cognitive and operational performance must be maintained. Method: A systematic review of the electronic databases Medline (PubMed), EMBASE (Scopus), PsycINFO, and Web of Science was conducted from inception up to September 2018. Eligibility criteria included a healthy human cohort, an outcome of cognition or military task performance and assessment of an environmental condition. Results: The search returned 113,850 records, of which 124 were included in the systematic review. Thirty-one studies examined the impact of heat stress on cognition; 20 of cold stress; 59 of altitude exposure; and 18 of being below sea level. Conclusion: The severity and duration of exposure to the environmental stressor affects the degree to which cognitive performance can be impaired, as does the complexity of the cognitive task and the skill or familiarity of the individual performing the task. Application: Strategies to improve cognitive performance in extreme environmental conditions should focus on reducing the magnitude of the physiological and perceptual disturbance caused by the stressor. Strategies may include acclimatization and habituation, being well skilled on the task, and reducing sensations of thermal stress with approaches such as head and neck cooling.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Le Ge ◽  
Qiuhua Yu ◽  
Chuhuai Wang ◽  
Huanjie Huang ◽  
Xin Li ◽  
...  

Abstract Background The capacity of postural control is a key factor related to falling in older people, particularly in older women with low back pain (LBP). Cognitive involvement in postural control increases with age. However, most scholars have not considered different difficulty levels of cognitive loads when exploring the effects of cognition on postural control in older patients with LBP. The present study is to investigate how different levels of cognitive loads modulate postural control in older women with LBP. Methods This was a cross-sectional study. Twenty older women with LBP were recruited into the LBP group, and 20 healthy older women without the history of LBP were recruited into the healthy control group. Balance parameters were computed to quantify postural control. All participants underwent the balance test, which required the participant to maintain stability during standing on a force platform with or without a concurrent cognitive task. The balance test included three levels of difficulties of posture tasks (eyes-open vs. eyes-closed vs. one-leg stance) and three cognitive tasks (without cognitive task vs. auditory arithmetic task vs. serial-7 s arithmetic task). Results A repeated-measure analysis of variance (3 postural tasks × 3 congnitive tasks× 2 groups) testing the effects of the different congnitive task levels on the performance in different postural conditions. Older women with LBP had worse postural control (as reflected by larger center of pressure (COP) parameters) than control group regardless of postural or cognitive difficulties. Compared with the single task, the COP parameters of participants with LBP were larger during dual tasks, even though the difficulty level of the cognitive task was low. Larger COP parameters were shown only if the difficulty level of the cognitive task was high in control group. Correlations between sway area/sway length and the number of falls were significant in dual tasks. Conclusion Our findings shed light on how cognitive loads modulate postural control for older women with LBP. Compared with control group, cognitive loads showed more disturbing effects on postural control in older women with LBP, which was associated with falling.


Author(s):  
Zahra Nadimi ◽  
Mansoureh Adel Ghahraman ◽  
Ghassem Mohammadkhani ◽  
Reza Hoseinabadi ◽  
Shohreh Jalaie ◽  
...  

Background and Aim: Vestibular system has several anatomical connections with cognitive regions of the brain. Vestibular disorders have negative effects on cognitive performance. Hearing-impaired patients, particularly cochlear implant users, have concomitant vestibular disor­ders. Previous studies have shown that attention assigned to postural control decreases while per­forming a cognitive task (dual task) in hearing-impaired children. Since the vestibular system and postural control performance develop around 15−16 years of age, the aim of this study was to compare postural control performance during dual task in adolescent boys with normal hearing and cochlear implant (CI) users with congenital hearing-impairment. Methods: Postural control was assessed in twenty 16−19 year old cochlear implant boys and 40 normal hearing peers with force plate. The main outcomes were displacement in posterior- anterior and medial-lateral planes, and mean speed with and without cognitive task and under on/off-device conditions. Caloric test was per­formed for CI users in order to examine the peri­pheral vestibular system. Results: Ninety-five percent of CI users showed caloric weakness. There were no significant diff­erences in postural control parameters between groups. All performances deteriorated in the foam pad condition compared to the hard surface in all groups. Total mean velocity significantly increased during dual task in normal hearing group and in CI users with off-device. Conclusion: Although CI users had apparent vestibular disorders, their postural control in both single and dual-task conditions was identical to the normal peers. These effects can be attributed to the vestibular compensation that takes place during growing. Keywords: Balance; postural control; dual task; congenital hearing loss; cochlear implant


Author(s):  
Megan J. Blakely ◽  
Kyle Wilson ◽  
Paul N. Russell ◽  
William S. Helton

The effects of physical activity on cognition and the effects of cognitive load on physical activity are complex. Both the nature of the physical activity and cognitive task may influence the interactive effects of performing a physical task while also performing a cognitive task. In a previous study examining the impact of increasing cognitive load on outdoor running speed and the impact of outdoor running on cognitive performance, Blakely et al. (2015) found running speed decreased as cognitive load increased. They also found that the impact of running itself on cognitive performance occurred when the cognitive task was itself demanding (high cognitive load). In the current study we expanded on this previous research by improving the experimental task to rule out peripheral sensory, not central or executive, interference and by incorporating heart rate measures and VO2 max estimates. Twelve runners completed five conditions, two seated cognitive tasks (one low load and one high load), two dual running cognitive tasks and one run only. Results were similar to the original experiment, as the cognitive task became more difficult, voluntary running speed decreased. Also the effects of running on cognitive performance (counting) were found only when the cognitive task was high load.


2013 ◽  
Vol 45 (4) ◽  
pp. 279-287 ◽  
Author(s):  
Ann-Katrin Stensdotter ◽  
Anne Kristin Wanvik ◽  
Håvard W. Lorås

Author(s):  
Drew McRacken ◽  
Maddie Dyson ◽  
Kevin Hu

Over the past few decades, there has been a significant number of reports that suggested that reaction times for different sensory modalities were different – e.g., that visual reaction time was slower than tactile reaction time. A recent report by Holden and colleagues stated that (1) there has been a significant historic upward drift in reaction times reported in the literature, (2) that this drift or degradation in reaction times could be accounted for by inaccuracies in the methods used and (3) that these inaccurate methods led to inaccurate reporting of differences between visual and tactile based reaction time testing.  The Holden study utilized robotics (i.e., no human factors) to test visual and tactile reaction time methods but did not assess how individuals would perform on different sensory modalities.  This study utilized three different sensory modalities: visual, auditory, and tactile, to test reaction time. By changing the way in which the subjects were prompted and measuring subsequent reaction time, the impact of sensory modality could be analyzed. Reaction time testing for two sensory modalities, auditory and visual, were administered through an Arduino Uno microcontroller device, while tactile-based reaction time testing was administered with the Brain Gauge. A range of stimulus intensities was delivered for the reaction times delivered by each sensory modality. The average reaction time and reaction time variability was assessed and a trend could be identified for the reaction time measurements of each of the sensory modalities. Switching the sensory modality did not result in a difference in reaction time and it was concluded that this was due to the implementation of accurate circuitry used to deliver each test. Increasing stimulus intensity for each sensory modality resulted in faster reaction times. The results of this study confirm the findings of Holden and colleagues and contradict the results reported in countless studies that conclude that (1) reaction times are historically slower now than they were 50 years ago and (2) that there are differences in reaction times for different sensory modalities (vision, hearing, tactile). The implications of this are that utilization of accurate reaction time methods could have a significant impact on clinical outcomes and that many methods in current clinical use are basically perpetuating poor methods and wasting time and money of countless subjects or patients.


2018 ◽  
Vol 15 (1) ◽  
pp. 199-215 ◽  
Author(s):  
Thomas Edward Marshall ◽  
Sherwood Lane Lambert

ABSTRACT This paper presents a cognitive computing model, based on artificial intelligence (AI) technologies, supporting task automation in the accounting industry. Drivers and consequences of task automation, globally and in accounting, are reviewed. A framework supporting cognitive task automation is discussed. The paper recognizes essential differences between cognitive computing and data analytics. Cognitive computing technologies that support task automation are incorporated into a model delivering federated knowledge. The impact of task automation on accounting job roles and the resulting creation of new accounting job roles supporting innovation are presented. The paper develops a hypothetical use case of building a cloud-based intelligent accounting application design, defined as cognitive services, using machine learning based on AI. The paper concludes by recognizing the significance of future research into task automation in accounting and suggests the federated knowledge model as a framework for future research into the process of digital transformation based on cognitive computing.


2019 ◽  
Vol 25 (Suppl. 1-2) ◽  
pp. 60-71 ◽  
Author(s):  
Nikolaus E. Wolter ◽  
Karen A. Gordon ◽  
Jennifer L. Campos ◽  
Luis D. Vilchez Madrigal ◽  
David D. Pothier ◽  
...  

Introduction: To determine the impact of a head-referenced cochlear implant (CI) stimulation system, BalanCI, on balance and postural control in children with bilateral cochleovestibular loss (BCVL) who use bilateral CI. Methods: Prospective, blinded case-control study. Balance and postural control testing occurred in two settings: (1) quiet clinical setting and (2) immersive realistic virtual environment (Challenging Environment Assessment Laboratory [CEAL], Toronto Rehabilitation Institute). Postural control was assessed in 16 and balance in 10 children with BCVL who use bilateral CI, along with 10 typically developing children. Children with neuromotor, cognitive, or visual deficits that would prevent them from performing the tests were excluded. Children wore the BalanCI, which is a head-mounted device that couples with their CIs through the audio port and provides head-referenced spatial information delivered via the intracochlear electrode array. Postural control was measured by center of pressure (COP) and time to fall using the WiiTM (Nintendo, WA, USA) Balance Board for feet and the BalanCI for head, during the administration of the Modified Clinical Test of Sensory Interaction in Balance (CTSIB-M). The COP of the head and feet were assessed for change by deviation, measured as root mean square around the COP (COP-RMS), rate of deviation (COP-RMS/duration), and rate of path length change from center (COP-velocity). Balance was assessed by the Bruininks-Oseretsky Test of Motor Proficiency 2, balance subtest (BOT-2), specifically, BOT-2 score as well as time to fall/fault. Results: In the virtual environment, children demonstrated more stable balance when using BalanCI as measured by an improvement in BOT-2 scores. In a quiet clinical setting, the use of BalanCI led to improved postural control as demonstrated by significant reductions in COP-RMS and COP-velocity. With the use of BalanCI, the number of falls/faults was significantly reduced and time to fall increased. Conclusions: BalanCI is a simple and effective means of improving postural control and balance in children with BCVL who use bilateral CI. BalanCI could potentially improve the safety of these children, reduce the effort they expend maintaining balance and allow them to take part in more complex balance tasks where sensory information may be limited and/or noisy.


2018 ◽  
Vol 32 (12) ◽  
pp. 1319-1329 ◽  
Author(s):  
Mark Moss ◽  
Ellen Smith ◽  
Matthew Milner ◽  
Jemma McCready

Background: The use of herbal extracts and supplements to enhance health and wellbeing is increasing in western society. Aims: This study investigated the impact of the acute ingestion of a commercially available water containing an extract and hydrolat of rosemary ( Rosmarinus officinalis L. syn. Salvia rosmarinus Schleid.). Aspects of cognitive functioning, mood and cerebrovascular response measured by near-infrared spectroscopy provided the dependent variables. Methods: Eighty healthy adults were randomly allocated to consume either 250 mL of rosemary water or plain mineral water. They then completed a series of computerised cognitive tasks, followed by subjective measures of alertness and fatigue. Near-infrared spectroscopy monitored levels of total, oxygenated and deoxygenated haemoglobin at baseline and throughout the cognitive testing procedure. Results: Analysis of the data revealed a number of statistically significant, small, beneficial effects of rosemary water on cognition, consistent with those found previously for the inhalation of the aroma of rosemary essential oil. Of particular interest here are the cerebrovascular effects noted for deoxygenated haemoglobin levels during cognitive task performance that were significantly higher in the rosemary water condition. This represents a novel finding in this area, and may indicate a facilitation of oxygen extraction at times of cognitive demand. Conclusion: Taken together the data suggest potential beneficial properties of acute consumption of rosemary water. The findings are discussed in terms of putative metabolic and cholinergic mechanisms.


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