scholarly journals The Effect of a Verbal Cognitive Task on Postural Sway Does Not Persist When the Task Is Over

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8428
Author(s):  
Kayla Bohlke ◽  
Xiaonan Zhu ◽  
Patrick J. Sparto ◽  
Mark S. Redfern ◽  
Caterina Rosano ◽  
...  

Dual-task balance studies explore interference between balance and cognitive tasks. This study is a descriptive analysis of accelerometry balance metrics to determine if a verbal cognitive task influences postural control after the task ends. Fifty-two healthy older adults (75 ± 6 years old, 30 female) performed standing balance and cognitive dual-tasks. An accelerometer recorded movement from before, during, and after the task (reciting every other letter of the alphabet). Thirty-six balance metrics were calculated for each task condition. The effect of the cognitive task on postural control was determined by a generalized linear model. Twelve variables, including anterior–posterior centroid frequency, peak frequency and entropy rate, medial-later entropy rate and wavelet entropy, and bandwidth in all directions, exhibited significant differences between baseline and cognitive task periods, but not between baseline and post-task periods. These results indicate that the verbal cognitive task did alter balance, but did not bring about persistent effects after the task had ended. Traditional balance measurements, i.e., root mean square and normalized path length, notably lacked significance, highlighting the potential to use other accelerometer metrics for the early detection of balance problems. These novel insights into the temporal dynamics of dual-task balance support current dual-task paradigms to reduce fall risk in older adults.

2016 ◽  
Vol 32 (6) ◽  
pp. 541-547 ◽  
Author(s):  
Renee Beach Sample ◽  
Kurt Jackson ◽  
Allison L. Kinney ◽  
Wiebke S. Diestelkamp ◽  
Senia Smoot Reinert ◽  
...  

Falls occur in 33% of older adults each year, some leading to moderate to severe injuries. To reduce falls and fall-related injuries, it is important to identify individuals with subtle risk factors elevating their likelihood of falling. The objective of this study was to determine how postural sway measures differed between fallers and nonfallers under standard and dual-task conditions. Quietstanding posturography measures were collected from 150 older adults during standard, cognitive, manual, and cognitive+manual tasks, and analyzed through traditional and nonlinear analyses. Of the traditional measures, M/L sway range and 95% confidence ellipse sway area showed statistically significant differences in all 4 test conditions between fallers and nonfallers. Although the manual dual task showed the most stable balance, effect sizes demonstrated larger differences between fallers and nonfallers. Nonlinear analysis revealed M/L sample entropy and M/L α-scaling exponent differentiating between fallers and nonfallers, with the cognitive task demonstrating larger differences. Based on the results, it is recommended to: (1) apply M/L sway range and 95% confidence ellipse area, (2) use the manual task to differentiate between fallers and nonfallers when using traditional analyses, and (3) use the cognitive task and M/L alpha and M/L sample entropy when using nonlinear analyses.


2010 ◽  
Vol 104 (6) ◽  
pp. 3510-3517 ◽  
Author(s):  
Hyun Gu Kang ◽  
Lewis A. Lipsitz

Distractions affect postural control, but this mechanism is not well understood. Diversion of resources during cognitive stress may lead to decreased motor drive and postural muscle tone. This may appear as decreased postural stiffness and increased postural sway amplitude. We hypothesized that dual tasking leads to decreased stiffness and increased sway amplitude. Postural sway (center of pressure; COP) data were used from 724 participants aged 77.9 ± 5.3 yr, a representative sample of community-dwelling older adults, the MOBILIZE Boston Study cohort. Subjects stood barefoot with eyes open for 30 s per trial on a force plate. Five trials were performed each with and without a serial subtractions-by-3 task. Sway data were fit to a damped oscillator inverted pendulum model. Amplitudes (COP and center of mass), mechanical stiffness, and damping of the sway behavior were determined. Sway amplitudes and damping increased with the dual task ( P < 0.001); stiffness decreased only mediolaterally ( P < 0.001). Those with difficulty doing the dual task exhibited larger sway and less damping mediolaterally ( P ≤ 0.001) and an increased stiffness with dual task anteroposteriorly (interaction P = 0.004). Dual task could still independently explain increases in sway ( P < 0.001) after accounting for stiffness changes. Thus the hypothesis was supported only in mediolateral sway. The simple model helped to explain the dual task related increase of sway only mediolaterally. It also elucidated the differential influence of cognitive function on the mechanics of anteroposterior and mediolateral sway behaviors. Dual task may divert the resources necessary for mediolateral postural control, thus leading to falls.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 72-73
Author(s):  
Melike Kahya ◽  
On-Yee Lo ◽  
Junhong Zhou ◽  
Alvaro Pascual-Leone ◽  
Lewis Lipsitz ◽  
...  

Abstract In older adults, the extent to which performing a cognitive task when standing diminishes postural control is predictive of future falls and cognitive decline. The cortical control of such “dual-tasking,” however, remains poorly understood. Electroencephalogram (EEG) studies have demonstrated that the level of attention and cognitive inhibitory activity during cognitive task performance can be quantified by changes in brain activity in specific frequency bands; namely, an increase in theta/beta ratio and a decrease in alpha-band power, respectively. We hypothesized that in older adults, dual-tasking would increase theta/beta ratio and decrease alpha-band power, and, that greater alpha-band power during quiet standing would predict worse dual-task performance. To test this hypothesis, we recorded postural sway and EEG (32-channels) in 30 older adults without overt disease as they completed trials of standing, with and without verbalized serial subtractions, on four separate visits. Postural sway speed, as well as absolute theta/beta power ratio and alpha-band power, were calculated. The theta/beta power ratio and alpha-band power demonstrated high test-retest reliability during quiet and dual-task standing across visits (intra-class correlation coefficients &gt;0.70). Compared with quiet standing, dual-tasking increased theta/beta power ratio (p&lt;0.0001) and decreased alpha-band power (p=0.002). Participants who exhibited greater alpha-band power during quiet standing demonstrated a greater dual-task cost (i.e., percent increase, indicative of worse performance) to postural sway speed (r=0.3, p=0.01). These results suggest that in older adults, dual-tasking while standing increases EEG-derived metrics related to attention, and, that greater cognitive inhibitory activity during quiet standing is associated with worse dual-task standing performance.


Author(s):  
Toby J. Ellmers ◽  
Elmar C. Kal ◽  
William R. Young

Abstract Background Persistent dizziness without a clear cause is common in older adults. We explored whether an anxiety-driven preoccupation with consciously processing balance may underpin the distorted perceptions of unsteadiness that characterises ‘unexplained’ dizziness in older adults. Methods We experimentally induced anxiety about losing one’s balance (through a postural threat manipulation) in a cohort of asymptomatic older adults and evaluated associated changes in perceived stability, conscious movement processing and postural control. These outcomes were also assessed when performing a distracting cognitive task designed to prevent anxiety-related conscious movement processing, in addition to during baseline conditions (ground level). Results Despite a lack of increase in postural sway amplitude (p = 0.316), participants reported reductions in perceived stability during postural threat compared to baseline (p < 0.001). A multiple linear regression revealed that anxiety-related conscious movement processing independently predicted perceptions of instability during this condition (p = 0.006). These changes were accompanied by alterations in postural control previously associated with functional dizziness, namely high-frequency postural sway and disrupted interaction between open- and closed-loop postural control (ps < 0.014). While the distraction task successfully reduced conscious processing (p = 0.012), leading to greater perceived stability (p = 0.010), further increases in both postural sway frequency (p = 0.002) and dominance of closed-loop control (p = 0.029) were observed. Conclusion These findings implicate the role of conscious movement processing in the formation of distorted perceptions of unsteadiness, suggesting that such perceptions may be modifiable by reducing an over-reliance on conscious processes to regulate balance.


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


2019 ◽  
Author(s):  
Hamid Allahverdipour ◽  
Iman Dianat ◽  
Galavizh Mameh ◽  
mohammad Asghari Jafarabadi

Abstract Background: The aim of this study was to evaluate the effects of cognitive and physical loads on dynamic and static balance of older adults under single, dual and multi-task conditions. Methods: The effects of single versus combined (dual-task and multi-task) cognitive (to speak out the name of the weekdays in a reverse order) and physical (with three levels including handling weights of 1kg, 2kg and 3kg in each hand) loads on dynamic and static balance of 42 older adults (21 males and 21 females), aged ≥ 60 years were studied. Dynamic and static balance measures were evaluated using the Timed Up and Go (TUG) and stabilometer (sway index) tests, respectively. Results: The TUG speed of female participants was generally slower than that of male participants. Cognitive task influenced the participants’ dynamic balance during the dual-task conditions, while the static balance was not affected in this phase. The dynamic and static balance measures were more influenced when performing the multi-tasks than when doing the dual-tasks. The effects of various levels of physical demand on the dynamic balance varied greatly under dual- and multi-task conditions. Conclusions: The findings add to the understanding of the factors influencing the elderly balance and control under cognitive and physical functioning.


2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S793-S794
Author(s):  
Manuel E Hernandez

Abstract Mobility impairments are prevalent in older adults. Whereas walking had traditionally been viewed as an autonomous process, evidence over the last decade has shown that cognitive processes such as attention and executive function have a significant impact on gait function in older adults. However, the exact neural mechanisms underlying difficulties in the control of mobility in older adults remains an open question. We examine the changes in the executive control of mobility in older adults with mobility impairments using functional near-infrared spectroscopy, as operationalized by performance in the community balance and mobility scale (CB&M). We hypothesized that prefrontal cortical (PFC) activity increases would be higher in older adults with mobility impairments, compared with older adults without mobility impairment, as dual-task walking difficulty increased. Older adults with (n=10, mean±SD age: 77±8 years, 8 females, CB&M= 58±12) and without mobility impairment (n=14, mean±SD age: 63±9 years, 11 females, CB&M= 87±6) were recruited from the local community. Dual-task walking was performed at a comfortable pace, while the difficulty of the concurrent cognitive task was increased using the modified Stroop test. PFC activity was measured using measures of oxygenated hemoglobin across the PFC. Older adults with mobility impairments demonstrated disproportionate increases in PFC activity, in comparison to those without mobility impairments, as the difficulty of the concurrent cognitive task increased (P&lt;.001), even after controlling for age. In conclusion, these data suggest that older adults with mobility impairments may require greater attentional resources than those without mobility impairments when concurrently performing thinking and walking tasks.


2017 ◽  
Vol 80 (9) ◽  
pp. 539-548
Author(s):  
Anna Rossiter ◽  
Matthew J Allsop ◽  
Rachael K Raw ◽  
Lindsay Howard ◽  
Raymond J Holt ◽  
...  

Introduction Older adults show increased postural sway and a greater risk of falls when completing activities with high cognitive demands. While dual-task approaches have clarified an association between cognitive processes and postural control, it is unclear how manual ability, which is also required for the successful completion of cognitively demanding tasks (such as putting a key into a lock), affects this relationship. Method Kinematic technology was used to explore the relationship between postural sway and manual control in healthy younger and older adults. Participants ( n = 82) remained standing to complete a visual-motor tracking task on a tablet computer. Root mean square tracking error measured manual performance, and a balance board measured deviations in centre of pressure as a marker of postural sway. Results Older adults displayed poorer manual accuracy and increased postural sway across all testing conditions. Conclusions Cognitive capacity can interact with multiple task demands, and in turn affect postural sway in older adults. Improving our understanding of factors that influence postural control will assist falls-prevention efforts and inform clinical practice.


Sign in / Sign up

Export Citation Format

Share Document