Cognitive-Motor Interference during Walking in Older Adults with Probable Mild Cognitive Impairment

Toward Development of a Novel Proprioceptive Trail-Making Test: Comparing Healthy Dancers and Non-Dancers

There is a pressing need for ecologically valid versions of traditional neuropsychological tests indexing executive function (EF), such as the Trail-Making Task (TMT), that incorporate movement and bodily awareness in healthy participants with varying abilities. We designed a proprioceptive version of the TMT (pTMT) that involved coordinated gross motor movement and proprioceptive awareness to investigate whether this measure of visual attention, task switching, and working memory positively correlated with a computerized version of the TMT (the dTMT). We aimed to establish the initial validity of our proprioceptive TMT (pTMT) by comparing performances on the dTMT and pTMT among a cohort of 36 healthy participants (18 dancers, 18 non-dancers; M age = 22, SD = 5.27; 64% female) anticipating that dancers would express higher intrinsic bodily awareness than non-dancers. Results revealed a mild to moderate but statistically significant positive correlation between dTMT and pTMT completion times [part A: r (36) = .33, p = .04; part B: r (36) = .37, p = .03] and numbers of errors [part B: r (36) = .41, p = .01] across both participant groups. These data suggest partial measurement convergence between these two TMT versions. Relative to non-dancers, dancers exhibited a higher level of performance (likely due to their better proprioceptive ability) through their faster completion times on dTMT-B [t (34) = 3.81, p = .006, d = 1.27] and pTMT-B [t (34) = 2.97, p = .005, d = .99], and their fewer errors on dTMT-B [t (34) = 2.93, p = .006, d = 1.0]. By identifying cognitive differences between these different groups of healthy individuals, our data contribute to both a theoretical understanding and the initial development of gross motor movement-based cognitive assessments, providing a path toward the further refinement of an ecologically valid full-body TMT.

Factors influencing gait performance in older adults in a dual-task paradigm

The aim of this study was to determine the effect of cognitive interference through a dual-task (DT) paradigm on gait parameters by sex or other predictive variables, such as physical fitness, health status, and cognition. A total of 125 older adults joined in this study (age, 72.42 ± 5.56 years old; 28 men and 97 women). The DT paradigm was evaluated through Comfortable Linear Gait (CLG) and Complex Gait Test (CGT). The gait parameters between single task (ST) vs. DT condition in men showed a significant reduction in speed (p < 0.001), cadence (p < 0.001), and step length (p = 0.049) and increased time to execute the CGT (p < 0.001), while women showed a decreased speed (p = 0.014), cadence (p < 0.001), and double support coefficient variation (CV) (p = 0.024) and increased single support time (p < 0.001) and CV step length (p < 0.05). In addition, women increased CGT time (p < 0.001). Furthermore, correlations between DT cost (DTC) cadence vs. Physical Activity for Elderly questionnaire (PASE) (r =  - 0.399; p = 0.008), DTC single support vs. 30 s Sit to Stand Test (r = - 0.356; 0.016), DTC single support vs. Rey Auditory Verbal Learning Test-Learning curve (r =  - 0.335; p = 0.023), DTC double support vs. 30 s Sit to Stand Test (r =  - 0.590; p < 0.001), DTC CV step length vs. 30 s Sit to Stand (r =  - 0.545; p = 0.003), and DTC CGT vs. 30 s Sit to Stand Test (r =  - 0.377; p = 0.048) were found. The results of our study indicate that the gait parameters within the DT condition decreased speed and cadence, while increasing CV step length and CGT time, causing slower gait with shortened steps in men and women.

Development and External Validation of a Gait Test Based Diagnostic Model for Detecting Mild Cognitive Impairment

OBJECTIVE

To address the lack of large-scale screening tools for mild cognitive impairment (MCI), this study aimed to assess the discriminatory ability of several gait tests for MCI and develop a screening tool based on gait test for MCI.

DESIGN

A diagnostic case-control test.

SETTING

The general community.

PARTICIPANTS

We recruited 134 older adults (≥65 years) for the derivation sample, comprising -69 individuals in the cognitively normal group and -65 in the MCI group (N=134). An additional 70 participants were enrolled for the validation sample.

INTERVENTIONS

All participants completed gait tests consisting of a single task (ST) and 3 dual tasks (DTs): counting backwards, serial subtractions 7, and naming animals.

MAIN OUTCOME MEASURES

Binary logistic regression analyses were used to develop models, and the efficacy of each model was assessed using receiver operating characteristic (ROC) curve and area under the curve (AUC). The best effective model was the final diagnostic model and validated using ROC curve and calibration curve.

RESULTS

The DT gait test incorporating serial subtractions 7 as the cognitive task demonstrated the highest efficacy with the AUC of 0.906 and the accuracy of 0.831 in detecting MCI with "years of education" being adjusted. Furthermore, the model exhibited consistent performance across different age and sex groups. In external validation, the model displayed robust discrimination (AUC=0.913) and calibration (calibrated intercept=-0.062, slope=1.039).

CONCLUSIONS

The DT gait test incorporating serial subtractions 7 as the cognitive task demonstrated robust discriminate ability for MCI. This test holds the potential to serve as a large-scale screening tool for MCI, aids in the early detection and intervention of cognitive impairment in older adults.

Cognitive, physical and emotional determinants of activities of daily living in nursing home residents-a cross-sectional study within the PROCARE-project

BACKGROUND

Interdependencies of health, fitness, cognition, and emotion can promote or inhibit mobility. This study aimed to analyse pathways and interactions between individual subjective and objective physical performance, cognition, and emotions with activities of daily living (ADLs) as mobility indicators in multimorbid nursing home residents.

METHODS

The study included n = 448 (77.1% females, age = 84.1 ± 7.8 years) nursing home residents. To describe the participant's demographics, frailty, number of falls, and participating institutions' socioeconomic status (SES) were assessed. ADLs were measured with the Barthel Index (BI; dependent variable). Independent variables included objective physical performance, subjective physical performance, cognition, and emotions. A structural equation model (SEM) with maximum likelihood estimation was conducted with AMOS. Direct and indirect effects were estimated using standardized coefficients (significance level of 0.05).

RESULTS

Indices showed (Chi2(148) = 217, PCMIN/DF = 1.47; p < .001; Comparative Fit Index = .940; Tucker Lewes Index = .902, RMSEA = .033) that the model fitted the data adequately. While there was no direct association between emotions, subjective physical performance, and ADLs, objective physical performance and cognition predicted higher ADLs (p < .01). Emotions had a strong relationship with subjective physical performance, and cognition had a moderate relationship with objective physical performance.

DISCUSSION AND CONCLUSION

Objective performance and cognition predicted higher functional status, as expressed by higher BI scores. ADLs, such as mobility, dressing, or handling tasks, require motor and cognitive performance. Subjective performance is an important predictor of ADLs and is only partly explained by objective performance, but to a large extent also by emotions. Therefore, future interventions for nursing home residents should take a holistic approach that focuses not only on promoting objective physical and cognitive performance but also on emotions and perceived physical performance.

TRIAL REGISTRATION

Trial registration number: DRKS00014957.

The Effect of Cognitive Task Complexity on Healthy Gait in the Walking Corsi Test

Dual-task activities are essential within everyday life, requiring visual-spatial memory (VSM) and mobility skills. Navigational memory is an important component of VSM needed to carry out everyday activities, but this is often not included in traditional tests such as the Corsi block tapping test (CBT). The Walking Corsi Test (WalCT) allows both VSM and navigational memory to be tested together, as well as allowing measures of gait to be collected, thus providing a more complete understanding of dual-task function. The aim of this study was to investigate the effect of an increasingly complex cognitive task on gait in a healthy adult population, using the WalCT and body-worn inertial measurement unit (IMU) sensors. Participants completed both the CBT and WalCT, where they were asked to replicate increasingly complex sequences until they were no longer able to carry this out correctly. IMU sensors were worn on the shins throughout the WalCT to assess changes in gait as task complexity increased. Results showed that there were significant differences in several gait parameters between completing a relatively simple cognitive task and completing a complex task. The type of memory used also appeared to have an impact on some gait variables. This indicates that even within a healthy population, gait is affected by cognitive task complexity, which may limit function in everyday dual-task activities.

Localized White Matter Tract Integrity Measured by Diffusion Tensor Imaging Is Altered in People with Mild Cognitive Impairment and Associated with Dual-Task and Single-Task Gait Speed

BACKGROUND

Altered white matter (WM) tract integrity may contribute to mild cognitive impairment (MCI) and gait abnormalities.

OBJECTIVE

The purpose of this study was to determine whether diffusion tensor imaging (DTI) metrics were altered in specific portions of WM tracts in people with MCI and to determine whether gait speed variations were associated with the specific DTI metric changes.

METHODS

DTI was acquired in 44 people with MCI and 40 cognitively normal elderly controls (CNCs). Fractional anisotropy (FA) and radial diffusivity (RD) were measured along 18 major brain WM tracts using probabilistic tractography. The average FA and RD along the tracts were compared between the groups using MANCOVA and post-hoc tests. The tracts with FA or RD differences between the groups were examined using an along-tract exploratory analysis to identify locations that differed between the groups. Associations between FA and RD in whole tracts and in the segments of the tracts that differed between the groups and usual/dual-task gait velocities and gross cognition were examined.

RESULTS

Lower FA and higher RD was observed in right cingulum-cingulate gyrus endings (rh.ccg) of the MCI group compared to the CNC group. These changes were localized to the posterior portions of the rh.ccg and correlated with gait velocities.

CONCLUSION

Lower FA and higher RD in the posterior portion of the rh.ccg adjacent to the posterior cingulate suggests decreased microstructural integrity in the MCI group. The correlation of these metrics with gait velocities suggests an important role for this tract in maintaining normal cognitive-motor function.

Does tandem balance test predict cognitive impairment among older adults? Findings from Longitudinal Ageing Study in India, 2017-18

BACKGROUND

Ageing entails a decline in physical and functional abilities including a reduced body balance due to complex integration and coordination of sensory acuity, motor control, neural and cognitive functions. This study aimed to examine the association between tandem balance test and cognitive impairment among older Indian adults. The study also examined the gender differentials in the associations with an interaction analysis.

METHODS

Data for this study were drawn from the recent release of the Longitudinal Ageing Study in India (2017-18). The total sample size for the present study included 26,539 older adults age 60 years and above. Descriptive statistics and bivariate analysis were used to present the preliminary results. Two sample proportion test was used to evaluate the significance for gender differences. Further, multivariable binary logistic regression analysis was used to evaluate the independent association of balance test performance and cognitive impairment among older adults.

RESULTS

Nearly 16% of male and 26% of female older adults could not finish full tandem test in this study. There were significant gender differences in cognitive impairment among older adults (male-6.5% and female-18.9%). The likelihood of cognitive impairment was significantly higher among older adults who could not finish the full tandem test compared to those who finished the tandem test [AOR: 1.22; CI: 1.09-1.36]. The interaction model revealed that older females who could not finish the full tandem test were 2.11 times significantly more likely to be cognitively impaired in reference to older males who finished the full tandem test [AOR: 2.11; CI: 1.81,2.45]. Similarly, older females who finished the full tandem test were 2.42 times significantly more likely to be cognitively impaired in reference to older males who finished the full tandem test [AOR: 2.42; CI: 2.02,2.88].

CONCLUSION

The findings of the study suggest that healthcare professionals working with older adults should consider the results of a balance test to screen for their risk of cognitive impairment. Results from the relationship between failing to finish the tandem test and cognitive impairment may be helpful for identifying older men and women who are at higher risk of experiencing mobility decline and their progression to dementia.

A dual-task gait test detects mild cognitive impairment with a specificity of 91.2

Background

Mild cognitive impairment (MCI) is a valuable intervention window in the progress of senile dementia, but the question of how to easily and conveniently detect MCI in the community remains unanswered. Gait performance reflects cognitive function, but how to reliably detect MCI through gait testing is still being explored.

Objective

To develop a dual-task gait testing method that could reliably detect MCI in the community.

Methods

A cross-sectional diagnostic study was conducted in 111 older adults (mean age = 72.14 ± 6.90 years) from five communities in Wuhan, China. A novel dual-task gait testing method, walking while identifying animals in pictures (AniP-DT gait test), was developed. The participants were classified into MCI or cognitively intact based on their performance on the Montreal Cognitive Assessment Scale (MoCA). Gait performance was assessed using both single-task and the AniP-DT gait test. Multiple linear regression and binary logistic regression were used to model the association between gait speed and cognitive status, and receiver operating characteristic (ROC) curve analysis was used to assess the discrimination ability.

Results

Compared to the cognitively intact group, the gait speed of the MCI group was lower in both single-task and the AniP-DT gait tests. The gait speed of the AniP-DT gait test was significantly associated with MoCA scores after adjusting the covariates and exhibited good discrimination ability in MCI detection (AUC = 0.814), with a specificity of 91.2%. ROC analysis of the logistic models revealed better discrimination ability of dual-task gait velocity when adjusted with age and years of education (AUC = 0.862).

Conclusion

The evidence in this study suggested that the AniP-DT gait test could be an easy and reliable screening tool for MCI in community older adults.

Including cognitive assessments with functional testing predicts capabilities relevant to everyday walking in older adults

BACKGROUND

Dual-task (DT) testing reflects real-world walking demands in older adults but is not always feasible to perform in clinic. Whether clinical measures that predict single-task (ST) performance also predict DT performance or dual-task effects (DTEs) has not been fully explored.

RESEARCH QUESTION

What are the relationships between cognitive performance, functional mobility, and self-reported physical activity and balance confidence and ST and DT Gait Speed and Cognitive Reaction Time, as well as DTEs on Gait Speed (DTE_GS) and Cognitive Reaction Time (DTE_RT), in older adults?

METHODS

Sixty-two older adults (71.5 ± 7.1 years, 17 males) completed cognitive performance, functional mobility, and self-report physical activity and balance confidence assessments. Three 1-min trials were performed: 1) ST Cognition (clock task), 2) ST Gait and 3) DT Cognition + Gait, with Cognitive Reaction Time (recorded during clock task performance via DirectRT) and Gait Speed (measured during walking trial via APDM system) recorded, and DTE_GS and DTE_RT calculated, as the cognitive and gait outcomes. Six multivariate regressions were conducted to test whether cognitive performance, functional mobility, and self-report assessments predicted Gait Speed and Cognitive Reaction Time in ST and DT conditions and DTEs.

RESULTS

The Comprehensive Trail Making Test (CTMT) predicted Reaction Time in ST cognitive (β = - 0.525, p = .003) and DT (β = - 0.510, p = .006) trials. The Physical Activity Scale for the Elderly (PASE) predicted DTE_RT (β = - 0.397, p = .008). The 10-Meter Walk Test (10MWT) predicted Gait Speed in ST gait (β = 0.692, p < .001) and DT (β = 0.715, p < .001) trials. The Four Square Step Test (FSST) predicted ST Gait Speed (β = - 0.233, p = .034). The Montreal Cognitive Assessment (MoCA) (β = 0.293, p = .027), 10MWT (β = 0.322, p = .046), and the FSST (β = 0.378, p = .019) predicted DTE_GS.

SIGNIFICANCE

The 10MWT, CTMT, and MoCA can be easily implemented in the clinic and may be good choices to assess cognitive and functional abilities necessary for ambulation in older adults.

Which motor-cognitive abilities underlie the digital Trail-Making Test? Decomposing various test scores to detect cognitive impairment in Parkinson's disease-Pilot study

Since Parkinson's disease (PD) is a heterogeneous disorder with symptoms, such as tremors, gait and speech disturbances, or memory loss, individualized diagnostics are needed to optimize treatment. In their current form, the typical paper-pencil methods traditionally used to track disease progression are too coarse to capture the subtleties of clinical phenomena. For this reason, digital biomarkers that capture, for example, motor function, cognition, and behavior using apps, wearables, and tracking systems are becoming increasingly established. However, given the high prevalence of cognitive impairment in PD, digital cognitive biomarkers to predict mental progression are important in clinical practice. This pilot study aimed to identify those components of our digital version of the TMT (dTMT) that allow discrimination between PD patients with and without cognitive deficits. A total of 30 healthy control (age 66.3 ± 8.61) and 30 participants with PD (age 68.3 ± 9.66) performed the dTMT using a touch-sensitive tablet to capture enhanced performance metrics, such as the speed between and inside circles. The decomposition of cognitive abilities based on integrating additional variables in the dTMT revealed that the Parkinson's disease group was significantly more sensitive to parameters of inhibitory control. In contrast, the mild cognitive impairment group was sensitive to parameters of cognitive flexibility and working memory. The dTMT allows objective, ecologically valid, and long-term cognitive and fine-motor performance tracking, suggesting its potential as a digital biomarker in neurodegenerative disorders.

Profiles of Motor-Cognitive Interference in Parkinson's Disease-The Trail-Walking-Test to Discriminate between Motor Phenotypes

Background and Aims. Most research on Parkinson’s disease (PD) focuses on describing symptoms and movement characteristics. Studies rarely focus on the early detection of PD and the search for suitable markers of a prodromal stage. Early detection is important, so treatments that may potentially change the course of the disease can be attempted early on. While gait disturbances are less pronounced in the early stages of the disease, the prevalence, and severity increase with disease progression. Therefore, postural instability and gait difficulties could be identified as sensitive biomarkers. The aim was to evaluate the discriminatory power of the Trail-Walking Test (TWT; Schott, 2015) as a potential diagnostic instrument to improve the predictive power of the clinical evaluation concerning the severity of the disease and record the different aspects of walking. Methods. A total of 20 older healthy (M = 72.4 years, SD = 5.53) adults and 43 older adults with PD and the motor phenotypes postural instability/gait difficulty (PIGD; M = 69.7 years, SD = 8.68) and tremor dominant (TD; M = 68.2 years, SD = 8.94) participated in the study. The participants performed a motor-cognitive dual task (DT) of increasing cognitive difficulty in which they had to walk a given path (condition 1), walk to numbers in ascending order (condition 2), and walk to numbers and letters alternately and in ascending order (condition 3). Results. With an increase in the cognitive load, the time to complete the tasks (seconds) became longer in all groups, F(1.23, 73.5) = 121, p < 0.001, ɳ2p = 0.670. PIGD showed the longest times in all conditions of the TWT, F(2, 60) = 8.15, p < 0.001, ɳ2p = 0.214. Mutual interferences in the cognitive and motor domain can be observed. However, clear group-specific patterns cannot be identified. A differentiation between the motor phenotypes of PD is especially feasible with the purely motor condition (TWT-M; AUC = 0.685, p = 0.44). Conclusions. PD patients with PIGD must be identified by valid, well-evaluated clinical tests that allow for a precise assessment of the disease’s individual fall risk, the severity of the disease, and the prognosis of progression. The TWT covers various aspects of mobility, examines the relationship between cognitive functions and walking, and enables differentiation of the motor phenotypes of PD.

The cognitive and cognitive-motor training contribution to the improvement of different aspects of executive functions in healthy adults aged 65 years and above-A randomized controlled trial

AIMS

The study aimed at examining the effectiveness of cognitive-motor dual-task and single-task cognitive training on executive and attention functions in participants over 65 years of age.

METHODS

The study comprised 68 participants. They were randomly assigned to dual-task cognitive-motor training (DTT), single-task cognitive training (STT) or a control group (C). The training program in all groups encompassed 4 weeks and consisted of three, 30-min meetings a week. Specialized software was designed for the purposes of the study. Both before and after the training, the cognitive functioning was assessed using: Color Trials Test, Ruff Figural Fluency Test, Wisconsin Sorting Card Test, Digit Span, Verbal Fluency Test, Stroop Color-Word Test.

RESULTS

After the cognitive-motor training, improvement was achieved in the control and inhibition of reactions. Moreover, after the cognitive training, improvements in abstract thinking and categorization were reported.

CONCLUSION

Despite the small sample limitation, the preliminary result shows each form of the training supports a different aspect of executive functions but does not contribute to the improvement in attention.

Do the dual-task "8-foot up and go" tests provide additional predictive value for early detection of cognitive decline in community-dwelling older women?

BACKGROUND

The 8-Foot Up and Go (8UG) test is a widely used mobility assessment. Some dual-task mobility assessments have been developed to help detect cognitive decline.

AIMS

This study developed a dual-task version of 8UG test to investigate the dual-task 8UG performance and to evaluate the ability of dual-task 8UG test in detecting cognitive decline.

METHODS

A total of 101 eligible community-dwelling women aged 60-74 years were grouped into the mild cognitive impairment group (MCI, n = 49) and the non-cognitive impairment group (NCI, n = 52). The 8UG tests under single-task (ST), manual dual-task (MT), and cognitive dual-task (CT) conditions were performed respectively. The dual-task cost (DTC) and the correct response rate (CRR) were calculated to quantify the dual-task interference.

RESULTS

Participants spent more time in performing the 8UG test under dual-task conditions. No differences were observed between NCI and MCI groups for 8UG parameters under ST and MT conditions (p > 0.05). When executing CT, significant differences were found in the number of correct answers and CRR (p < 0.05). CRR showed the strongest ability to predict MCI with a cut-off point of 0.50 (71.2% sensitivity and 61.2% specificity).

DISCUSSION

Both manual and cognitive dual-task were found to interfere with the 8UG performance. CRR with cutoff point of 0.50 could be a potential predictor of MCI in community-dwelling older women.

CONCLUSIONS

The CRR of the cognitive dual-task 8UG test could be recommended as a potential predictor for the early detection of MCI in community-dwelling older women.

The Effects of Combined Physical and Cognitive Interventions on Direct and Indirect Fall Outcomes for the Elderly with Mild Cognitive Impairment: A Systematic Review

This review was intended to determine the effectiveness of physical and cognitive training (PCT) on falls and fall-related factors and cognitive function among community-dwelling elderly people with mild cognitive impairment (MCI). A systematic literature search was performed of the MEDLINE, CINAHL, Web of Sciences, Scopus, ProQuest, Embase, and Google Scholar databases for articles published from 2010 to 2020. The studies that combined PCT to assess their impacts on fall outcomes both directly and indirectly were included. Study quality was assessed using the standardized JBI Critical Appraisal Tool for RCTs. The standardized data extraction tool from JBI-MAStARI was used to extract data of included studies. Seven RCTs involving 740 participants were included. The overall fall incidence did not significantly decrease after the interventions. However, PCT significantly impacted the cognitive function and physical activities of elderly people with MCI, particularly improving their balancing ability, gait speed, muscular strength, and executive functions. This study indicated that combining PCT improves balance ability, gait speed, and executive functioning in the elderly with MCI, which may help to minimize fall occurrence.

Psychometric Properties of the Trail Walking Test for People With Stroke

Objective

To investigate (i) the inter-rater and test–retest reliability of the trail walking test (TWT) and the minimum detectable change in the TWT completion time; (ii) the correlations between the TWT completion time and stroke-specific impairments; and (iii) the cutoff TWT completion time to distinguish between people with stroke and healthy older adults according to dual-tasking ambulation ability.

Design

Cross-sectional study.

Setting

University-based rehabilitation center.

Participants

In total, 104 people with stroke and 53 healthy older adults.

Main Outcome Measures

The TWT, the Fugl–Meyer Assessment of Lower Extremity (FMA-LE), the ankle muscle strength test, the limit of stability (LOS) test, the Berg Balance Scale (BBS), the Timed Up and Go test (TUG), and the Community Integration Measure (CIM).

Results

The mean TWT completion time in subjects with stroke was 124.906 s. The TWT demonstrated excellent inter-rater reliability [intraclass correlation (ICC) = 0.999] and good test–retest reliability (ICC = 0.876) in people with stroke. The TWT performance demonstrated significant negative correlations with the FMA-LE scores (r = −0.409), LOS movement velocity (affected and unaffected sides; r = −0.320 and −0.388, respectively), and LOS endpoint excursion (affected and unaffected sides; r = −0.357 and −0.394, respectively); a significant positive correlation with the LOS reaction time (affected side; r = 0.256); a moderate negative correlation with the BBS scores (r = −0.72); and an excellent positive correlation with the TUG completion time (r = 0.944). The receiver operating characteristic curve analysis revealed that an optimal cutoff of 69.61 s for the TWT completion time had an outstanding diagnostic power to distinguish between people with stroke and healthy older adults (area under the curve = 0.919) with high sensitivity (88.5%) and specificity (83.0%).

Conclusion

Results of our preliminary study demonstrated that the TWT is a reliable, valid, sensitive, and specific clinical test for evaluating dual-tasking ambulation ability in people with stroke aged 45 years or above and without cognitive impairments. It can differentiate the dual-tasking ambulation ability between people with stroke and healthy older adults.

Associations of Motor Performance and Executive Functions: Comparing Children with Down Syndrome to Chronological and Mental Age-Matched Controls

Background. Children with Down syndrome (DS) exhibit lower motor and cognitive performance than typically developing children (TD). Although there is a relationship between these two developmental domains, only a few studies have addressed this association in children with DS compared to groups of the same chronological age (CA) or mental age (MA) within one study. This study aimed to fill this research gap. Method and Procedures. The Movement Assessment Battery for Children-2 and the Trail-Making Test was used to assess motor and cognitive performances in 12 children (M = 10.5 ± 10.08) with DS, 12 CA-matched, and 12 MA-matched controls. Results. There are significant group differences in the motor dimension (total test score; p < 0.001, η²_p = 0.734), for processing speed (p < 0.001, η²_p = 0.396), and cognitive flexibility (p < 0.001, η²_p = 0.498). Between TD-CA and both other groups, the differences in the magnitude of correlations for the motor dimension balance are also significant (compared to DS: z = −2.489; p = 0.006, and to TD-MA: z = −3.12; p < 0.001). Conclusions. Our results suggest that the relationships depend on the studied cognitive and motor skills. It seems crucial to select a wide range of tasks for both domains that are as isolated as possible for future studies, to better understand the relationships between cognitive and motor skills in children with DS.

Arterial Stiffness and Cardiorespiratory Fitness Are Associated With Cognitive Function in Older Adults

Age-related cognitive impairment has been associated with arterial stiffening and decreased cardiorespiratory fitness. The aims of this cross-sectional study were to compare cognitive function domains and cardiovascular parameters in older adults (≥ 65 years old) with high and normal aortic stiffness (via carotid-femoral pulse wave velocity, cfPWV) and to explore relationships among cfPWV, carotid intima-media thickness, cardiorespiratory fitness, and cognitive function. Vascular and cognitive function were measured in older adults with either normal or high cfPWV. Cognitive function was measured via an intensive one-time neuropsychological battery, while cfPWV by applanation tonometry, carotid intima-media thickness and function (i.e., distensibility) by ultrasonography, and cardiorespiratory fitness (i.e., VO₂peak) by a submaximal exercise test. Correlations among age, VO₂peak, carotid intima-media thickness, cfPWV, and cognitive function were performed along with a series of multivariate analyses of variance. Compared with NAS, participants with HAS had greater aortic, carotid, and brachial blood pressures but similar cardiorespiratory fitness and carotid intima-media thickness and distensibility. Participants with NAS exhibited better neuropsychological performance in executive function and attention and overall cognitive function than those with HAS. When controlling for age, visual scanning and perception scores were correlated with cfPWV and VO₂peak. Our findings suggest that certain cognitive domains for older adults are associated with their cardiorespiratory fitness and aortic stiffness.

A Dual-Task Paradigm Using the Oral Trail Making Test While Walking to Study Cognitive-Motor Interactions in Older Adults

Objective: With aging, gait becomes more dependent on executive functions, especially on switching abilities. Therefore, cognitive-motor dual-task (DT) paradigms should study the interferences between gait and switching tasks. This study aimed to test a DT paradigm based on a validated cognitive switching task to determine whether it could distinguish older-old adults (OO) from younger-old adults (YO).

Methods: Sixty-five healthy older participants divided into 29 younger-old (<70 years) and 36 older-old (≥70 years) age groups were evaluated in three single-task (ST) conditions as follows: a cognitive task including a processing speed component [Oral Trail Making Test part A (OTMT-A)], a cognitive task including a switching component [Oral Trail Making Test part B (OTMT-B)], and a gait evaluation at normal speed. They were also evaluated under two DT conditions, i.e., one associating gait with OTMT-A and the other associating gait with OTMT-B. Cognitive and gait performances were measured. The comparison of cognitive and gait performances between condition, logistic regression, and receiver operating characteristic (ROC) analyses were performed.

Results: The cognitive and gait performances were differently affected by the different conditions (i.e., ST, DT, OTMT-A, and OTMT-B). The OTMT-B produced higher interference on gait and cognitive performances. Moreover, a higher number of errors on the OTMT-B performed while walking was associated with the older-old age group.

Conclusion: Using validated cognitive flexibility tasks, this DT paradigm confirms the high interference between switching tasks and gait in older age. It is easily implemented, and its sensitivity to age may highlight its possible usefulness to detect cognitive or motor declines.

Effects of Exergame-Based Dual-Task Training on Executive Function and Dual-Task Performance in Community-Dwelling Older People: A Randomized-Controlled Trial

Objective: Aging is associated with decline in executive function that may lead to reduced dual-task performance. Regular exercise has been recommended for promoting or maintaining mental and physical health in older adults, yet only a fraction of older adults exercise regularly. Exergame training may have the potential to enhance exercise adherence. Therefore, the aim of this study was to examine the effects of exergame-based dual-task training on executive function and dual-task performance in community-dwelling older adults. Materials and Methods: This was a single-blinded, randomized-controlled trial. Twenty community-dwelling older adults were recruited and randomly assigned to one of two groups. All participants completed 36 trainings, including three 60-minute sessions/week over 12 weeks. Participants in the experimental group received exergame-based dual-task training, while those in the control group received home-based multicomponent exercise training. Measures of executive function, dual-task performance, and community walking ability were assessed before and after the intervention. Results: Significant group × time interactions (P = 0.000-0.027) with large effects were found in all selected outcome measures. Compared with the control group, the experimental group improved significantly in measures of general executive function (P = 0.014), inhibitory control (P = 0.037), cognitive dual-task performance (P < 0.001), and community walking ability (P = 0.002). Enhanced general executive function was highly correlated with either improved motor dual-task performance (r = 0.674) or improved cognitive dual-task performance (r = -0.701). Conclusion: These results suggested that exergame-based dual-task training improved both executive function and dual-task performance in older people. These positive effects could be transferred to enhance community walking ability. Clinical Trial Registration number: ACTRN 12617000095369.

Dual task walking costs in older adults with mild cognitive impairment: a systematic review and meta-analysis

OBJECTIVE

The objective of this systematic review and meta-analysis (PROSPERO registration No CRD42020192121) is to review existing literature focusing on effects of different dual task paradigms on walking speed in older adults with and without Mild Cognitive Impairment.

METHODS

(1) Data Sources: PubMEd, Cumulative Index of Nursing and Allied Health, Cochrane library, and Web of Science. (2) Study Selection: The key terms searched included those associated with dual task, walking speed, executive function, older adults, and MCI. (3) Data Extraction: The search yielded 140 results with 20 studies meeting the inclusion criteria, which were rated by two independent reviewers using the Quality Assessment Tool. Descriptions of each study including the single and dual task protocol, outcome measure, and final outcomes were extracted. Meta-analysis was performed to evaluate the dual task effects on walking costs in older adults with and without MCI.

RESULTS

Meta-analysis revealed that there were significant differences in the dual task walking costs among older adults with or without MCI (p < .05). Pooled effect sizes of the serial subtraction (9.54; 95%CI, 3.93-15.15) and verbal fluency tasks (10.06; 95%CI, 6.26-15.65) showed that there are higher motor dual-task costs in older adults with MCI than age-matched controls. For quality assessment, all studies ranged from 12 to 16 in score, out of 18 (high quality).

CONCLUSIONS

In the studies included in this review, mental tracking tasks, consisting of serial subtraction and verbal fluency, were found to be the most sensitive in detecting MCI-related changes in older adults, and could serve an important role as a target measure for evaluating the efficacy of interventions aimed at improving cognitive and motor function in older adults.

An interrater reliability study of gait analysis systems with the dual task paradigm in healthy young and older adults

Background and aims

One reason for the controversial discussion of whether the dual task (DT) walking paradigm has an added value for diagnosis in clinical conditions might be the use of different gait measurement systems. Therefore, the purpose was 1) to detect DT effects of central gait parameters obtained from five different gait analysis devices in young and old adults, 2) to assess the consistency of the measurement systems, and 3) to determine if the absolut and proportional DT costs (DTC) are greater than the system-measurement error under ST.

Methods

Twelve old (72.2 ± 7.9y) and 14 young adults (28.3 ± 6.2y) walked a 14.7-m distance under ST and DT at a self-selected gait velocity. Interrater reliability, precision of the measurement and sensitivity to change were calculated under ST and DT.

Results

An age effect was observed in almost all gait parameters for the ST condition. For DT only differences for stride length (p < .029, ɳ²_p = .239) as well as single and double limb support (p = .036, ɳ²_p = .227; p = .034, ɳ²_p = .218) remained. The measurement systems showed a lower absolute agreement compared to consistency across all systems.

Conclusions

When reporting DT effects, the real changes in performance and random measurement errors should always be accounted for. These findings have strong implications for interpreting DT effects.

A combined stepping and visual tracking task predicts cognitive decline in older adults better than gait or visual tracking tasks alone: a prospective study

BACKGROUND

It is unclear whether motor-cognitive dual tasks predict cognitive decline better than either motor or cognitive tasks alone.

AIMS

To examine the utility of the novel motor-cognitive dual-task test [Stepping Trail Making Test (S-TMT)], as a predictor of cognitive decline, and compare its predictive performance with single motor or cognitive tests.

METHODS

This 2-year population-based prospective study included 626 adults aged ≥ 70 years from Takashimadaira, Itabashi, Tokyo. The S-TMT measured the time taken to step on 16 numbers in order. Gait speed and TMT-A were assessed with standardized methods as single motor and cognitive tasks, respectively. A decline in the Mini-Mental State Examination score by ≥ 3 points over 2 years was defined as a significant cognitive decline.

RESULTS

Over 2 years, 97 (15.5%) experienced cognitive decline. After adjusting for confounders, binary logistic regression models showed no significant associations between gait speed, TMT-A time tertiles, and risk of cognitive decline, but participants in the longest tertile of S-TMT time were more likely to develop cognitive decline than those of the shortest tertile (odds ratio 2.14; 95% confidence interval 1.17-3.90). Only the addition of the S-TMT time to the covariates model significantly improved the reclassification indices for predicting cognitive decline (net reclassification improvement: 0.31, P < 0.01; integrated discrimination improvement: 0.01, P = 0.02).

DISCUSSION AND CONCLUSION

Only the S-TMT was significantly associated with cognitive decline and improved reclassification indices, indicating that it is more useful for predicting cognitive decline than individual gait speed or visual tracking tests alone.

Effects of acute exercise at different intensities on fine motor-cognitive dual-task performance while walking: A functional near-infrared spectroscopy study

Studies on the effects of acute exercises on cognitive functions vary greatly and depend on the duration and intensity of exercise and the type of cognitive tasks. This study aimed to investigate the neural correlates that underpin the acute effects of high-intensity interval (HIIE) versus moderate-intensity continuous exercise (MCE) on fine motor-cognitive performance while walking (dual-task, DT) in healthy young adults. Twenty-nine healthy right-handers (mean age: 25.1 years ± 4.04; 7 female) performed the digital trail-making-test (dTMT) while walking (5 km/h) before and after acute exercise. During task performance, the hemodynamic activation of the frontopolar area (FPA), dorsolateral prefrontal (DLPFC), and motor cortex (M1) was recorded using functional near-infrared spectroscopy (fNIRS). Both HIIE and MCE resulted in improved dTMT performance, as reflected by an increase in the number of completed circles and a reduction in the time within and between circuits (reflecting improvements in working memory, inhibition, and decision making). Notably, HIIE evoked higher cortical activity on all brain areas measured in the present study than the MCE group. To our knowledge, these results provide the first empirical evidence using a mobile neuroimaging approach that both HIIE and MCE improve executive function during walking, likely mediated by increased activation of the task-related area of the prefrontal cortex and the ability to effectively use, among other things, high fitness levels as neural enrichment resources.

Gait Performance as an Indicator of Cognitive Deficit in Older People

Background: The purpose of this study was to analyze which gait variables are the best for detecting cognitive impairment and to determine if age and gender can influence gait variations in older people. Methods: 65 participants took part in this study (22 men and 43 women; age: 73.88 ± 9.56 years). We use the Montreal Cognitive Assessment (MoCA) to assess mild cognitive impairment (MCI). Gait speed (GS) and the complex gait test (CGT) were analyzed with photocells Witty (Microgate, Italia). The OptoGait system (Microgate, Italia) was used to analyze step length (SL) and step coefficient of variation (CV sl). Results: There was a significant association between MoCA and SL (r = 0.420; p = 0.002), CV sl (r = −0.591; p < 0.001), and CGT (r = −0.406; p = 0.001). Instrumental activities of daily living showed significant association with SL (r = 0.563; p < 0.001); CV sl (r = −0.762; p < 0.001), CGT (r = −0.622; p < 0.001), and GS (r = 0.418; p < 0.001). CV sl showed the best results with MoCA when linear regression analysis was applied (R² = 0.560; p = 0.007; Y = 23.669 − 0.320x). Participants older than 79 years showed lower MoCA scores and poorer gait parameters than people younger than 79 years. Conclusions: CV sl, SL, CGT, and GS make it possible to detect MCI in older people, especially when these variables are evaluated as a whole.

Dual-Task Gait Assessment in a Clinical Sample: Implications for Improved Detection of Mild Cognitive Impairment

OBJECTIVES

Research has longitudinally linked dual-task gait dysfunction to mild cognitive impairment (MCI) and dementia risk. Our group previously demonstrated that dual-task gait speed assessment distinguished between subjective cognitive complaints (SCC) and MCI in a memory clinic setting, and also found that differences in dual-task gait speed were largely attributable to executive attention processes. This study aimed to reproduce these findings in a larger diverse sample and to extend them by examining whether there were group differences in single- versus dual-task cognitive performance (number of letters correctly sequenced backward).

METHOD

Two-hundred fifty-two patients (M age = 66.01 years, SD = 10.46; 119 MCI, 133 SCC) presenting with cognitive complaints in an academic medical setting underwent comprehensive neuropsychological and gait assessment (single- and dual-task conditions).

RESULTS

Patients with MCI walked slower and showed greater decrement in cognitive performance than those with SCC during dual-task conditions. Neuropsychological measures of executive attention accounted for significant variance in dual-task gait performance across diagnostic groups beyond demographic and health risk factors.

DISCUSSION

Reproduction of our results within a sample over four times the previous size provides support for the use of dual-task gait assessment as a marker of MCI risk in clinical settings.

The trail-making-test: Comparison between paper-and-pencil and computerized versions in young and healthy older adults

One of the key challenges in assessing cognitive performance is to detect not only apparent impairment but to also pick up on subtle differences. Computerized tests benefit especially from the acquisition of fine-grained outcome measures. However, the equivalency of paper-based and computerized tests cannot be assumed. The Trail-Making-Test is a paper-pencil cognitive assessment tool (ppTMT) that has been used in many research studies to evaluate visuomotor abilities and mental flexibility. A digital version of the extended TMT (including a condition measuring fine motor speed) called the dTMT has been developed. This study aims to test (1) reliability, (2) equivalence, and (3) agreement of the ppTMT and dTMT. A total of 53 healthy individuals aged 19 to 82 years of age (22 men, 31 women; mean age 42.2, SD = 22.8) completed three trials per ppTMT and dTMT condition. Part M involves following a predefined path, Part A links numbers randomly distributed in space, in ascending order, and Part B alternates between linking numbers and letters. dTMT scores were highly reproducible, correlated strongly with paper-pencil administered durations, and discriminated young from older adults. Measures of reliability, sensitivity, and clinical meaning for dTMT scores were favorable compared with ppTMT-based testing. Our findings support the comparability of TMT-indices in computerized assessments. While many digital biomarker efforts are in progress (e.g., neurodegenerative disorders), the dTMT sets itself apart through its high sensitivity, the alternate forms, and the additional component measures. In this light, it could serve as a starting point for an early diagnostic tool.

Exploring motor-cognitive interference in children with Down syndrome using the Trail-Walking-Test

BACKGROUND AND AIMS

The dual-task (DT) paradigm is an ecologically valid approach to assess cognitive function in relation with motor demands, particularly for children with Down syndrome (DS). This study aimed to determine DT performance for a complex Change-of-Direction (CoD_W) walking task in children with DS.

METHODS

The sample included 12 children with DS (10.2 ± 1.19 years), 12 typically developing (TD) children matched for chronological (TD-CA: 10.2 ± 1.19 years) and 12 TD children matched for mental age (TD-MA: 5.50 ± 1.24 years). We examined DT performance with the Trail-Walking-Test (TWT): participants (1) walked along a fixed pathway, following a prescribed path, delineated by target markers of (2) increasing sequential numbers, and (3) increasing sequential numbers and letters. Motor and cognitive dual-task costs (DTC) were calculated.

RESULTS

For the TWT, an ANOVA with repeated measures revealed significant differences between DS and the CA, but not the MA group. Overall, there were significant decreases in speed with increasing cognitive demands. In addition, all children produced higher cognitive compared to motor DTC, which were more pronounced in the cognitively more challenging condition.

CONCLUSION

The assessment of motor and cognitive performance in a DT paradigm provided insight in how motor and/or cognitive impairment constrains the ability of children to successfully perform activities in a complex and dynamical environment.

Dual-Task Performance and Neurodegeneration: Correlations Between Timed Up-and-Go Dual-Task Test Outcomes and Alzheimer's Disease Cerebrospinal Fluid Biomarkers

BACKGROUND

Tools to identify individuals at preclinical stages of dementia disorders are needed to enable early interventions. Alterations in dual-task performance have been detected early in progressive neurodegenerative disorders. Hence, dual-task testing may have the potential to screen for cognitive impairment caused by neurodegeneration. Exploring correlations between dual-task performance and biomarkers of neurodegeneration is therefore of interest.

OBJECTIVE

To investigate correlations between Timed Up-and-Go dual-task (TUGdt) outcomes and Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers amyloid-β 42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau).

METHODS

This cross-sectional cohort study included 90 participants (age range 49-84 years) undergoing memory assessment, who were subsequently diagnosed with AD, other dementia disorders, mild cognitive impairment, or subjective cognitive impairment. TUG combined with "Naming Animals" (TUGdt NA) and "Months Backwards" (TUGdt MB), respectively, were used to assess dual-task performance. The number of correct words and time taken to complete the tests were measured. The CSF biomarkers were analysed by ELISA. Spearman's rank correlation was used for analyses between TUGdt outcomes (TUGdt NA and TUGdt MB), and CSF biomarkers, adjusted for age, gender, and educational level.

RESULTS

The number of correct words, as well as the number of correct words/10 s during TUGdt NA correlated negatively to CSF t-tau and p-tau. No correlations were found between any time scores and CSF biomarkers.

CONCLUSION

The correlations between TUGdt NA and t-tau and p-tau may indicate that neurodegeneration affects dual-task performance. Longitudinal studies are needed to further explore dual-task testing in screening for cognitive impairment due to neurodegeneration.

A Stepping Trail Making Test as an Indicator of Cognitive Impairment in Older Adults

This study aimed to examine the concurrent validity of a novel motor-cognitive dual-task test, the Stepping Trail Making Test (S-TMT), as an indicator of cognitive impairment (CI), and compare its screening performance to that of motor or cognitive tests alone. This was a population-based cross-sectional study including 965 Japanese adults aged ≥ 70 years. To measure the time taken to perform the S-TMT, the participants were instructed to step on 16 numbers in sequence as quickly and accurately as possible. Motor and cognitive functions were assessed by gait speed and TMT part A (TMT-A), respectively. Participants were classified into CI (< 24 points), mild CI (MCI, 24-27 points), and intact cognition (> 27 points) categories based on their Mini-Mental State Examination score. Binary logistic regression models showed that the addition of the S-TMT to the covariates model gave the highest discrimination index (c-statistics), and significantly improved reclassification indices (net reclassification improvement and integrated discrimination improvement) for screening both CI and MCI compared to those of gait speed or TMT-A alone. These results show that S-TMT has a concurrent validity as a dual-task test for screening CI and MCI and better discrimination and reclassification performance than motor or cognitive tests alone in older adults.

Complex Gait Is Related to Cognitive Functioning in Older People: A Cross-Sectional Study Providing an Innovative Test

BACKGROUND

Many studies have demonstrated an inverse relationship between gait performance and cognitive impairment. The main purposes of this study were: (1) to design and validate a complex gait test (CGT) in older people, (2) to analyze the effects of age and sex on CGT, and (3) to analyze the association between CGT performance and physical functioning and cognitive measures.

METHODS

A total of 279 older people (60-97 years) were analyzed in 2019. Fitness tests, gait performance, and several cognitive measures such asthe Trail-Walking Test and Montreal Cognitive Assessment were used.

RESULTS

The CGT reported adequate reliability and validity parameters. In the test-retest analysis, the intra-class correlation coefficient was 0.868 (p < 0.001). There was a significant correlation between the CGT and Trail-Walking Test (r = 0.592; p < 0.001). The linear regression analysis showed that the CGT was associated with the Montreal Cognitive Assessment (R2 = 0.357; p =0.001). The binary logistic regression analysis revealed that a high CGT score was a risk factor for mild cognitive impairment (odds ratio 1.201, 95% CI 1.081-1.334; p = 0.001). The ROC curve of the mild cognitive impairment was predicted by the CGT performance (area under the curve = 0.768, 95% CI 0.647-0.889; p < 0.001), reaching the cut-off point at 20.25 s.

CONCLUSIONS

The CGT showed good reliability and validity and may serve as a potential biomarker in mild cognitive impairment prediction in older adults aged 60-97 years.

Reliability and construct validity of a novel motor-cognitive dual-task test: A Stepping Trail Making Test

AIM

This study aimed to examine the reliability and construct validity of the Stepping Trail Making Test (S-TMT) in community-dwelling older adults.

METHODS

This study comprised a cross-sectional study based on a population sample. Participants comprised 1224 community-dwelling older Japanese women aged 65-81 years without functional disability, dementia, depression, Parkinson's disease, or cognitive and visual impairments. The S-TMT measured the time taken to step on a sequence of numbers (1-16) positioned on a mat (1 m² ). Participants were instructed to step as quickly and accurately as possible. Motor functions were assessed by walking speed and knee extensor strength tests, while cognitive functions were assessed by the Symbol Digit Substitution Task (SDST) test, verbal and logical memory test, and TMT-A and -B.

RESULTS

As a result of test-retest reliability over 6 months, the intraclass correlation coefficients of the S-TMT was 0.82 (95% confidence interval, 0.68-0.90). An adjusted multiple regression model indicated that the S-TMT was significantly associated with walking speed for motor function, and associated with the SDST, TMT-A and TMT-B for cognitive functions (P < 0.001).

CONCLUSIONS

These results suggest that the S-TMT is a reliable dual-task test comprising mobility for motor function and a visual-dependent execution function for cognitive function in older women. Geriatr Gerontol Int 2020; 20: 291-296.

Impact of adding a cognitive task while performing physical fitness tests in women with fibromyalgia: A cross-sectional descriptive study

Fibromyalgia symptoms cause a significant reduction in the ability to perform daily life activities. These activities often require the ability to perform more than 1 task at the same time.The aim was to investigate how the addition of a cognitive task modifies the performance in physical fitness tests in fibromyalgia and healthy controls.A total of 61 women participated in this study, 31 of them diagnosed with fibromyalgia by a rheumatologist. They performed 3 physical fitness tests (arm curl, handgrip, and 10-steps stair tests) in 2 conditions:The dual task cost was calculated as the difference between the performances in the regular and dual-task (DT) conditions.Healthy controls obtained significantly better results than fibromyalgia in both, dual and single-task conditions. Women with fibromyalgia significantly decreased the performance in the 10-steps stair test when a cognitive task was added. Between-group differences in the dual-task costs (DTC) were not found.Women with fibromyalgia showed lower physical performance than healthy controls in both, single and dual task conditions. In addition, differences between single and dual task conditions were observed in the 10-steps stair test in women with fibromyalgia. This could be related with a reduction in the ability to perform daily life activities. However, results regarding DTC indicate that both groups may be similarly influenced by the addition of a secondary cognitive. Thus, further research with different difficulty levels of DT conditions is needed in fibromyalgia.

Investigating the interference pattern of dual tasks using serial decomposition

BACKGROUND

Specific investigation of dual task-interference (DTI) may help researchers to develop the optimal training exercise for enhancing the performance of daily activities.

OBJECTIVES

To reveal the DTI by comparing the performances between personalized single tasks (cognitive or motor task) and dual task with serial decomposition in normal healthy adults.

METHODS

After a preliminary period, healthy participants randomly (n = 46) performed three computerized experiments of cognitive (CT), motor (MT) and dual tasks (DT). In CT, participants were required to release button 1 (BT1) as rapidly as possible when the font color of a word and its meaning were congruent (Go), and in MT, they had to release BT1 and then tap button 2 (BT2) 10 times as rapidly as possible if the symbol "○" was presented (Go). The DT consisted of a combination of CT and MT elements. The reaction time (RT) of correct releases (RTCR) of BT1 in all tasks was measured, as well as the button shifting time between releasing BT1 and pressing BT2, and the finger tapping rate in MT and DT. To obtain the DTI values, we calculated the RTCR ratio in CT and MT and divided the outcome by the RTCR of DT.

RESULTS

The ratio of RTCR in CT (% CT/DT, 78.6±13.0%) and MT (% MT/DT, 74.2±10.1%) were significantly lower than the ratio of RTCR in DT (% DT/DT, 100%). The button shifting time of MT was at 92.0±23.7% of baseline, and the finger tapping rate of MT was 106.1±19.1%, which was significantly higher than baseline.

CONCLUSIONS

The % DT/DT is significantly higher than both % CT/DT and % MT/DT, which suggests that the cognitive load depends on the type of cognitive task that is being performed. Additionally, the significant increase of % DT/DT compared to % CT/DT indicated that there is a cognitive load prior to a motor task. The increased button shifting time and decreased tapping rate in DT may indicate that a residual cognitive load and a concurrent motor load were present.

Profiles of Cognitive-Motor Interference During Walking in Children: Does the Motor or the Cognitive Task Matter?

The evidence supporting the effects of age on the ability to coordinate a motor and a cognitive task show inconsistent results in children and adolescents, where the Dual-Task Effects (DTE) – if computed at all – range from either being lower or comparable or higher in younger children than in older children, adolescents and adults. A feasible reason for the variability in such findings is the wide range of cognitive tasks (and to some extend of motor tasks) used to study Cognitive-Motor Interference (CMI). Our study aims at determining the differences in CMI when performing cognitive tasks targeting different cognitive functions at varying walking pathways. 69 children and adolescents (boys, n = 45; girls, n = 24; mean age, 11.5 ± 1.50 years) completed higher-level executive function tasks (2-Back, Serial Subtraction, Auditory Stroop, Clock Task, TMT-B) in comparison to non-executive distracter tasks [Motor Response Task (MRT), TMT-A] to assess relative effects on gait during straight vs. repeated Change of Direction (COD) walking. DT during COD walking was assessed using the Trail-Walking-Test (TWT). The motor and cognitive DTE were calculated for each task. There were significant differences between 5th and 8th graders on single gait speed on the straight (p = 0.016) and the COD pathway (p = 0.023), but not on any of the DT conditions. The calculation of DTEs revealed that motor DTEs were lowest for the MRT and highest for the TWT in the numbers/letters condition (p < 0.05 for all comparisons). In contrast, there were cognitive benefits for the higher-order cognitive tasks on the straight pathways, but cognitive costs for both DT conditions on the COD pathway (p < 0.01 for all comparisons). Our findings demonstrate that DT changes in walking when completing a secondary task that involve higher-level cognition are attributable to more than low-level divided attention or motor response processes. These results specifically show the direct competition for higher-level executive function resources important for walking, and are in agreement with previous studies supporting the cognitive-motor link in relation to gait in children. This might be in line with the idea that younger children may not have adequate cognitive resources.