The effect of different types of cognitive tasks on postural sway fluctuations in older and younger adults: A nonlinear study.

BACKGROUND: There are numerous types of cognitive tasks classified as mental tracking (MT), working memory (WM), reaction time (RT), discrimination and decision-making and verbal fluency (VF). However, limited studies have investigated the effects of cognitive task type on postural control in older adults. PURPOSE: s: The aim of this study was to investigate the effect of aging and several types of cognitive tasks on postural control in terms of nonlinear analysis. METHOD: Postural control was investigated under 6 conditions (single task and dual-task with RT; easy and difficult VF; easy and difficult WM; easy and difficult MT. Outcome measurements were the max Lyapunov, entropy, and correlation dimension at anteroposterior (AP) and mediolateral (ML) directions. RESULTS: The results revealed that within the older group, the AP & ML max Lyapunov at dual-task with difficult WM and MT was significantly higher than all other conditions. In addition, the older group had lower AP entropy at dual-task with easy VF, difficult WM, and easy as well as difficult MT. CONCLUSION: The results can be useful to understand the postural control mechanisms and to detect the alterations following aging and applying different types of cognitive tasks. In addition, the investigated parameters can be a basis for identifying postural control deficiencies.

Targeting negative flashforward imagery in speech anxiety with a visuospatial dual-task: Do attenuated flashforwards lead to less anxiety and avoidance?

BACKGROUND AND OBJECTIVES: It has been proposed that negative mental imagery plays an important role in the persistence of social fears. Experiencing vivid and distressing 'flashforward' images of a potential social catastrophe appears to be of relevance in speech anxiety. To clarify the role of these images, the current experimental study tested if reducing the vividness and distressing properties of recurring negative flashforward images subsequently reduces anxiety and avoidance tendencies regarding a speech. METHODS: Participants were female undergraduates high in speech anxiety (N = 134) who joined our study online. In the experimental condition, we used a visuospatial dual-task to reduce the vividness and distress of flashforward imagery. Primary outcomes were participants' self-reported anxiety and avoidance ratings in anticipation of and during an actual speech. As a secondary outcome, we used observer ratings of participants' anxiety during the speech. RESULTS: Participants reported moderate to high frequency and interference of their vivid and distressing flashforward images in daily life. The dual-task resulted in reductions in image vividness and distress. However, we found no differences between conditions in anxiety and avoidance ratings before and during the speech. LIMITATIONS: The imagery manipulation effect was moderate to small. Moreover, we included a subclinical sample. CONCLUSIONS: Reducing negative flashforward imagery vividness and distress with a visuospatial dual-task did not directly lead to less anxiety and avoidance tendencies related to a later speech. Thus, findings provided no support for the hypothesis that experiencing highly vivid and distressing flashforward images causally contributes to social fears.

The effect of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive control in multitasking.

Current research in brain stimulation suggests transcutaneous auricular vagus nerve stimulation (taVNS) as a promising tool to modulate cognitive functions in healthy populations, such as attention, memory, and executive functions. Empirical evidence in single-task contexts, suggests that taVNS promotes holistic task processing, which strengthens the integration of multiple stimulus features in task processing. However, it is unclear how taVNS might affect performance in multitasking, where the integration of multiple stimuli leads to an overlap in stimulus response translation processes, increasing the risk of between-task interference (crosstalk). In a single-blinded, sham-controlled, within-subject design, participants underwent taVNS while performing a dual task. To assess the effects of taVNS, behavioral (reaction times), physiological (heart rate variability, salivary alpha-amylase), and subjective psychological variables (e.g., arousal) were recorded over three cognitive test blocks. Our results revealed no overall significant effect of taVNS on physiological and subjective psychological variables. However, the results showed a significant increase in between-task interference under taVNS in the first test block, but not in the subsequent test blocks. Our findings therefore suggest that taVNS increased integrative processing of both tasks early during active stimulation.

Tai Chi practice enables prefrontal cortex bilateral activation and gait performance prioritization during dual-task negotiating obstacle in older adults.

Background: With aging, the cognitive function of the prefrontal cortex (PFC) declined, postural control weakened, and fall risk increased. As a mind-body exercise, regular Tai Chi practice could improve postural control and effectively prevent falls; however, underlying brain mechanisms remained unclear, which were shed light on by analyzing the effect of Tai Chi on the PFC in older adults by means of functional near-infrared spectroscopy (fNIRS). Methods: 36 healthy older adults without Tai Chi experience were divided randomly into Tai Chi group and Control group. The experiment was conducted four times per week for 16 weeks; 27 participants remained and completed the experiment. Negotiating obstacle task (NOT) and negotiating obstacle with cognitive task (NOCT) were performed pre- and post-intervention, and Brodmann area 10 (BA10) was detected using fNIRS for hemodynamic response. A three-dimensional motion capture system measured walking speed. Results: After intervention in the Tai Chi group under NOCT, the HbO2 concentration change value (ΔHbO2) in BA10 was significantly greater (right BA10: p = 0.002, left BA10: p = 0.001), walking speed was significantly faster (p = 0.040), and dual-task cost was significantly lower than pre-intervention (p = 0.047). ΔHbO2 in BA10 under NOCT was negatively correlated with dual-task cost (right BA10: r = -0.443, p = 0.021, left BA10: r = -0.448, p = 0.019). There were strong negative correlations between ΔHbO2 and ΔHbR under NOCT either pre-intervention (left PFC r = -0.841, p < 0.001; right PFC r = -0.795, p < 0.001) or post-intervention (left PFC r = -0.842, p < 0.001; right PFC r = -0.744, p < 0.001). Conclusion: Tai Chi practice might increase the cognitive resources in older adults through the PFC bilateral activation to prioritize gait performance during negotiating obstacles under a dual-task condition.

Dual-Task-Based Music Therapy to Improve Executive Functioning of Elderly Patients with Early Stage Alzheimer's Disease: A Multiple Case Study.

Deficits in executive functioning are a common feature of Alzheimer's disease (AD) and result from impairment in the central executive system. As a result, elderly patients with early stage AD may require interventions that are more cognitively intense than traditional interventions. To address this need, in this multiple case study, we explored a dual-task-based music therapy intervention that involved drum playing and singing designed to induce attentional and motor controls. Three octogenarians diagnosed with early stage AD participated in 12 dual-task-based music therapy sessions over 6 weeks. Measures of executive functioning and the performance of a bimanual drum tapping task were evaluated before and after the intervention. Improvements in executive functioning were observed for participants A and C. After the intervention, reduced mean synchronization errors were found for the simultaneous tapping condition for all three participants. Although there was variability in the functional changes between participants, it is noteworthy that positive improvements in the elderly patients with early stage AD were obtained following dual-task-based music therapy. The results suggest that music therapy integrated into the dual-task paradigm can be an effective way to address degenerative cognitive deficits among elderly patients with early stage AD.

Boosting long-term effects of degraded memories via acute stress.

Combining recall of an emotional memory with simultaneous horizontal eye movements (i.e., Recall + EM) reduces memory aversiveness. However, the long-term persistence of this effect is inconsistent across studies. Given that stress may aid in the consolidation of memories, we examined whether acute stress can boost the long-term effects of degraded memories. To test this, participants recalled two negative memories, which were assigned to a Recall + EM or Recall Only condition. Before and after each intervention they rated memory aversiveness (i.e., immediate effects) followed by a stress-induction or control procedure. After a 24h-period, participants rated each memory again (i.e., long-term effects). We found that Recall + EM produces immediate effects but that these effects dissolve over time. Moreover, acute stress did not boost potential long-term effects of Recall + EM. Degraded memories were not retained better by applying stress. We discuss these results and how long-term effectiveness may still be achieved.

Comparison of Wuqinxi Qigong with Stretching on Single- and Dual-Task Gait, Motor Symptoms and Quality of Life in Parkinson's Disease: A Preliminary Randomized Control Study.

The objective of this study was to investigate the therapeutic effect of Wuqinxi Qigong vs. stretching on single- and dual-task gait, motor symptoms, and quality of life in people with mild and moderate Parkinson's disease (PD). This single-blind, randomized control trial included 40 participants with idiopathic PD who were randomized into the Wuqinxi Qigong (WQ) group or stretching group. Participants completed 12 weeks (two sessions/week) of intervention. The primary outcomes were gait parameters when performing single-task (comfortable pace) and dual-task (obstacle crossing, serial-3 subtraction and backward digit span) walking, including gait speed, stride length, and double support percentage. The secondary outcomes were ratings from the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), results of the timed-up-and-go test (TUGT), results of the Mini-Balance Evaluation Systems Test (MiniBESTest), and responses from the 39-item Parkinson's Disease Questionnaire (PDQ-39). All measures were assessed pre- and post-intervention. The WQ group demonstrated increased gait speed (p = 0.000) during the single task, and increased stride length (p = 0.001, p = 0.021) during the single-task and serial-3 subtraction task. Double support percentage significantly decreased (p = 0.004) in the WQ group during the obstacle crossing task, and also decreased (p = 0.045) in the stretching group during the single-task. TUGT (p = 0.005), MiniBESTest (p = 0.023) and PDQ-39 (p = 0.043) in the WQ group significantly improved, and both groups showed significant improvement in MDS-UPDRS after intervention. Wuqinxi Qigong is an effective method to improve single- and dual-task gait. While both exercises improve motor symptoms, Wuqinxi Qigong results in better mobility, balance and quality of life compared to stretching alone.

Benefits of implanted peroneal functional electrical stimulation for continual gait adaptations in people with 'drop foot' due to chronic stroke.

BACKGROUND: Benefits of peroneal functional electrical stimulation in people with post-stroke drop foot may particularly emerge in environments that require continual gait adaptation. Such adaption is known to increase the attentional demands of gait. RESEARCH QUESTIONS: Is performance of a target stepping task more accurate and less attention demanding with electrical stimulation ON compared to OFF in people with post-stroke drop foot? METHODS: Thirteen people with an implanted electrical stimulation system participated in this observational study. Participants performed a walking task with irregularly spaced targets on a self-paced treadmill, both as a single task and combined with an auditory Stroop task. Participants performed each task with electrical stimulation ON and OFF. In the OFF condition participants were allowed to use their own ankle-foot orthosis. The effects of Device (ON, OFF) and interaction of Device*Task (single, dual) on stepping performance in mediolateral and anteroposterior direction were tested based on the total error of foot placement relative to the targets, using repeated measurements ANOVA. Differences between electrical stimulation ON and OFF on auditory Stroop task accuracy were assessed using a non-parametric Wilcoxon signed-rank test. Non-parametric correlations were calculated to associate changes in stepping performance with paretic leg motor function (Fugl-Meyer Assessment - leg score). RESULTS: Data of 12 participants were used for analysis. Mediolateral total error was smaller with peroneal functional electrical stimulation ON compared to OFF (Δ = 1.0 cm, p = 0.011). In the anteroposterior direction, no significant effects of Device were found. There were no significant interaction effects of Device*Task in either direction. Changes in total error (ON vs OFF) were not significantly associated with leg motor function. Stroop task accuracy was not statistically different between ON and OFF. SIGNIFICANCE: Implanted electrical stimulation may have benefits with regard to mediolateral accuracy of a continual target stepping task, although the effect size is relatively small. This benefit seems to be independent of the performance of a concurrent attention-demanding task and may reflect better gait stability in the mediolateral direction, which is known to be a problem in people with stroke.

Effects of Exergaming-Based Tai Chi on Cognitive Function and Dual-Task Gait Performance in Older Adults With Mild Cognitive Impairment: A Randomized Control Trial.

Background: Declined cognitive function interferes with dual-task walking ability and may result in falls in older adults with mild cognitive impairment (MCI). The mind-body exercise, Tai Chi (TC), improves cognition and dual-task ability. Exergaming is low-cost, safe, highly scalable, and feasible. Whether the effects of exergaming-based TC is beneficial than traditional TC has not been investigated yet. Objectives: The objective of this study was to investigate effects of exergaming-based TC on cognitive function and dual-task walking among older adults with MCI. Methods: Fifty patients with MCI were randomly assigned to an exergaming-based TC (EXER-TC) group, a traditional TC (TC) group, or a control group. The EXER-TC and TC groups received 36 training sessions (three, 50-min sessions per week) during a 12-week period. The control group received no intervention and were instructed to maintain their usual daily physical activities. The outcome variables measured included those related to cognitive function, dual-task cost (DTC), and gait performance. Results: The EXER-TC and TC groups performed better than the control group on the Chinese version of the Stroop Color and Word Test, the Trail Making Test Parts A and B, the one-back test, gait speed, and DTC of gait speed in cognitive dual-task conditions after training. However, there were no significant differences between the EXER-TC and TC groups. Compared with the control group, only the EXER-TC group experienced beneficial effects for the Montreal Cognitive Assessment. Conclusion: EXER-TC was comparable to traditional TC for enhancement of dual-task gait performance and executive function. These results suggested that the EXER-TC approach has potential therapeutic use in older adults with MCI.

A cognitively enhanced online Tai Ji Quan training intervention for community-dwelling older adults with mild cognitive impairment: A feasibility trial.

BACKGROUND: This study examines the feasibility, acceptability, and safety of a newly developed cognitive-enhancing Tai Ji Quan training intervention, delivered via remote videoconferencing, for older adults with mild cognitive impairment (MCI). METHODS: In a three-arm feasibility trial, community-dwelling older adults with MCI (N = 69; mean age = 74.6 years, 57% women) were randomized to a cognitively enhanced Tai Ji Quan (n = 23), standard Tai Ji Quan (n = 22), or stretching group (n = 24) and participated in a 60-minute online exercise session via Zoom, twice weekly for 16 weeks. Participants were recruited primarily in the state of Oregon through mass mailing and word of mouth. The primary outcomes were intervention feasibility (with respect to recruitment, online intervention delivery, fidelity and compliance, and attrition and retention rates), acceptability, and safety. We also assessed feasibility of online data collection and test-retest reliability and explored preliminary trends on secondary outcomes that included global cognitive function, dual-task cost, and domain-specific cognition function. RESULTS: The study had an average recruitment rate of 55%. Feasibility was demonstrated by the overall successful online program implementation, with good fidelity, acceptable compliance (76%), and excellent retention (94%). The cognitively enhanced Tai Ji Quan intervention was shown to be acceptable to participants as well as safe, with no major intervention-related moderate/severe events. At week 16, the group receiving cognitively enhanced Tai Ji Quan training showed a positive trend in the cognitive function and dual-task outcome measures whereas the group receiving standard Tai Ji Quan training exhibited positive trends on global and domain-specific cognitive measures. CONCLUSIONS: Preliminary findings of this pilot study indicate the feasibility, acceptability, and safety of a tailored, cognitively enhanced Tai Ji Quan training intervention delivered remotely to home settings via videoconferencing for community-dwelling older adults with MCI. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT04070703.

Combining Transcranial Direct Current Stimulation With Tai Chi to Improve Dual-Task Gait Performance in Older Adults With Mild Cognitive Impairment: A Randomized Controlled Trial.

Introduction: Engaging in a secondary task while walking increases motor-cognitive interference and exacerbates fall risk in older adults with mild cognitive impairment (MCI). Previous studies have demonstrated that Tai Chi (TC) may improve cognitive function and dual-task gait performance. Intriguingly, with emerging studies also indicating the potential of transcranial direct current stimulation (tDCS) in enhancing such motor-cognitive performance, whether combining tDCS with TC might be superior to TC alone is still unclear. The purpose of this study was to investigate the effects of combining tDCS with TC on dual-task gait in patients with MCI. Materials and Methods: Twenty patients with MCI were randomly assigned to receive either anodal or sham tDCS, both combined with TC, for 36 sessions over 12 weeks. Subjects received 40 min of TC training in each session. During the first 20 min, they simultaneously received either anodal or sham tDCS over the left dorsolateral prefrontal cortex. Outcome measures included dual-task gait performance and other cognitive functions. Results: There were significant interaction effects between groups on the cognitive dual task walking. Compared to sham, the anodal tDCS group demonstrated a greater improvement on cadence and dual task cost of speed. Conclusion: Combining tDCS with TC may offer additional benefits over TC alone in enhancing dual-task gait performance in patients with MCI. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [TCTR20201201007].

Motor Imagery of Walking in People Living with and without Multiple Sclerosis: A Cross-Sectional Comparison of Mental Chronometry.

Motor imagery represents the ability to simulate anticipated movements mentally prior to their actual execution and has been proposed as a tool to assess both individuals' perception of task difficulty as well as their perception of their own abilities. People with multiple sclerosis (pwMS) often present with motor and cognitive dysfunction, which may negatively affect motor imagery. In this cross-sectional study, we explored differences in motor imagery of walking performance between pwMS (n = 20, age = 57.1 (SD = 8.6) years, 55% female) and age- and sex-matched healthy controls (n = 20, age = 58.1 (SD = 7.0) years, 60% female). Participants underwent mental chronometry assessments, a subset of motor imagery, which evaluated the difference between imagined and actual walking times across four walking tasks of increasing difficulty (i.e., large/narrow-width walkway with/without obstacles). Raw and absolute mental chronometry (A-MC) measures were recorded in single- (ST) and dual-task (DT) conditions. In ST conditions, pwMS had higher A-MC scores across all walking conditions (p ≤ 0.031, η2 ≥ 0.119), indicating lower motor imagery ability compared to healthy controls. During DT, all participants tended to underestimate their walking ability (3.38 ± 6.72 to 5.63 ± 9.17 s). However, after physical practice, pwMS were less able to adjust their imagined walking performance compared to healthy controls. In pwMS, A-MC scores were correlated with measures of balance confidence (ρ = -0.629, p < 0.01) and the self-reported expanded disability status scale (ρ = 0.747, p < 0.01). While the current study revealed that pwMS have lower motor imagery of walking performance compared to healthy individuals, further work is necessary to examine how the disassociation between mental chronometry and actual performance relates to quality of life and well-being.

Dual-task intervention based on trail making test: Effects on Parkinson's disease.

OBJECTIVE: To evaluate the effectiveness of an intervention with dual task based on trail making test on gait, cognition and daily activities execution in individuals with Parkinson's disease. DESIGN: Randomized controlled trial. METHODOLOGY: 10 individuals with Parkinson's Disease (PD) were divided into dual task group (DTG) and control group (CG). Were realized 16 dual task (DT) training sessions based on the Trail Making Test (TMT) for DTG and a conventional training protocol for CG. Pre and post intervention assessments used the 6 minute walk test (T6), TMT, Katz Index and Falls Efficacy Scale (FES). RESULTS: Comparing the difference between pre and post intervention values between groups, there was no significant difference for T6 (p=0,36). In TMT there was a significant difference (p=0,03), showing shorter times for DTG. The tests used for time values in the Katz index tasks showed an important difference for the DTG (P=0,02). As for the results of the FES, they did not show pre and post changes in the DTG (0,45) and in the CG (p= 0,29) and not even between the groups (p=0,45). CONCLUSION: The proposed intervention was able to promote improvements in the performance of daily life activities, learning adaptations and retention of motor and cognitive aspects, which may reflect positively in the daily lives of patients with PD and, consequently, greater autonomy to perform these types of activities.

Implementing an Online Virtual Falls Prevention Intervention During a Public Health Pandemic for Older Adults with Mild Cognitive Impairment: A Feasibility Trial.

PURPOSE: This study evaluates the feasibility of delivering a virtual (online) falls prevention intervention for older adults with mild cognitive impairment (MCI). METHODS: Community-dwelling older adults with MCI (mean age = 76.2 years, 72% women) were randomized to either a Tai Ji Quan (n = 15) or stretching group (n = 15) and participated in 60-minute virtual exercise sessions, via Zoom, twice weekly for 24 weeks. The primary outcome was the incidence of falls. Secondary outcomes were the number of fallers and changes from baseline in the 4-Stage Balance Test, 30-second chair stands, and Timed Up and Go Test under both single- and dual-task conditions. RESULTS: The intervention was implemented with good fidelity, an overall attendance rate of 79%, and 13% attrition. Compared with stretching, Tai Ji Quan did not reduce falls (incidence rate ratio = 0.58; 95% confidence interval [CI], 0.32 to 1.03) or the number of fallers (relative risk ratio = 0.75; 95% CI, 0.46 to 1.22) at week 24. The Tai Ji Quan group, however, performed consistently better than the stretching group in balance (between-group difference in change from baseline, 0.68 points; 95% CI, 0.12 to 1.24), 30-second chair stands (1.87 stands; 95% CI, 1.15 to 2.58), and Timed Up and Go under single-task (-1.15 seconds; 95% CI, -1.85 to -0.44) and dual-task (-2.35; 95% CI, -3.06 to -1.64) conditions. No serious intervention-related adverse events were observed. CONCLUSION: Findings from this study suggest the feasibility, with respect to intervention fidelity, compliance, and potential efficacy, of implementing an at-home, virtual, interactive Tai Ji Quan program, delivered in real-time, as a potential balance training and falls prevention intervention for older adults with MCI. The study provides preliminary data to inform future trials.

Reliability of postural control during double-leg standing in subjects with nonspecific chronic low back pain: Dual-task paradigm and manipulated visual and somatosensory inputs.

BACKGROUND: The aim of this study is to evaluate the test-retest reliability of the Center of Pressure (COP) parameters in quiet double-leg standing in subjects with Non-Specific Chronic Low Back Pain (NSCLBP) during dual taking associated with manipulated visual and somatosensory inputs. MATERIALS AND METHODS: In this observational cross-sectional study, the static balance of thirty NSCLBP patients were assessed during a double-leg stance by using the force platform. Subjects were accosted by manipulated somatosensory and visual inputs during dual taking in eight different conditions (with and without vibration, eyes-open and eyes-closed, and with and without auditory Stroop test). The COP parameters were recorded as follows: range sideways and range fore-aft as well as mean velocity and area variables. The cognitive task parameters included the reaction time and error ratio. The intra-class correlation coefficient (ICC) was computed to assess the intersession reliability of COP parameters. RESULTS: in intersession, range sideways, range fore-aft, and mean velocity measures possessed moderate to high ICC, but area owned high ICC only in one condition (double-leg stance, eyes-close, with vibration, and with auditory Stroop test). Notably, other conditions had low ICC, and moderate to high and low to very high ICC were reported for reaction time and error ratio. CONCLUSION: Among the parameters studied in the present study, the mean velocity measure seems to be the most reliable variable of postural control in the subjects with NSLBP especially in more challenging conditions, i.e., quiet double-leg standing with eyes closed and adding vibratory inputs during dual-tasking.

Comparison of postural control in older adults under different dual-task conditions: A cross-sectional study.

BACKGROUND: and purpose: Performing a cognitive task while maintaining postural stability, known as "dual-task" condition, can increase the cognitive demand and reduce the postural control capacity. The inability to allocate attention to postural control under dual-task conditions may lead to balance impairments, particularly in older adults. The present study aimed to compare the effects of different dual-task conditions of backward counting (BC) and visual attention (VA) on older adults' postural balance performance. METHODS: Twenty asymptomatic volunteers (mean age: 70.4 ± 4.1 years) were recruited. Participants stood on a foam surface placed over a force plate, and displacement and sway velocity of their center of pressure (COP) in anterior-posterior (AP) and medial-lateral (ML) directions were recorded under three conditions: BC dual-task, VA dual-task (control of center of mass with a laser pointer), and quiet stance as the control task (CT). RESULTS: Repeated measures ANOVA showed a significant difference in AP and ML sway velocities between conditions with p-values of 0.039 and 0.042, respectively. The LSD post-hoc test revealed that the BC task significantly increased AP sway velocity compared to the CT (p = 0.013), and the VA task significantly increased ML sway velocity compared to the CT (p = 0.034) and the BC tasks (p = 0.026). There were no statistically significant differences between conditions for ML (p = 0.058) and AP (p = 0.350) displacements and total sway velocity (p = 0.051). CONCLUSION: Older adults' postural stability can be impaired under dual-task conditions and the present study revealed that various dual tasks increase postural sway in different directions.

Effect of dance therapies on motor-cognitive dual-task performance in middle-aged and older adults: a systematic review and meta-analysis.

PURPOSE: To systematically review the effectiveness of dance-based programs to improve motor-cognitive dual-task performance in middle-aged and older adults. MATERIALS AND METHODS: Five scientific databases were selected to identify the articles included in this systematic review. Ninety-one articles were found in the electronic databases. Fourteen articles fulfilled all inclusion and exclusion criteria. The methodological quality of the studies was assessed with a modified version of Downs and Black checklist. PRISMA guidelines were followed in the data extraction process. The overall effect size of the improvements was calculated through a meta-analysis. RESULTS: All the studies had an acceptable methodological quality. Dance-based interventions had a duration of 8-52 weeks, 1-3 sessions per week, with sessions lasting 40-90 min. According to the overall effect size, dance-based interventions significantly improved dual-task performance (-0.48 with a 95% confidence interval from -0.88 to -0.08). CONCLUSIONS: Dance-based intervention programs may be effective at improving the performance on motor-cognitive dual-task in middle-aged and older adults. Apart from the effects on the cognitive Time Up and Go test, dance interventions may also improve speed walking with a cognitive task. All these conclusions must be taken with caution due to the heterogeneity and the small number of articles. Future research can be developed to increase the knowledge on these issues.Implications for rehabilitationInterventions based on dance as part of rehabilitation can improve the performance on TUG under dual-task condition in aging.Interventions based on dance can be effective to improve the development of some tasks of daily life by reducing time in a motor task under dual task condition in aging.Physical therapists, personal trainers and other clinicians can use different types of dance for improving dual-tasking among the adults.

Dichotic listening while walking: A dual-task paradigm examining gait asymmetries in healthy older and younger adults.

Dual-task studies have employed various cognitive tasks to evaluate the relationship between gait and cognition. Most of these tests are not specific to a single cognitive ability or sensory modality and have limited ecological validity. In this study, we employed a dual-task paradigm using Dichotic Listening (DL) as concomitant cognitive task to walking. We argue that DL is a robust task to unravel the gait-cognition link in different healthy populations of different age groups. Thirty-six healthy older adults (Mean = 67.11) and forty younger adults (Mean = 22.75) participated in the study. DL consists of three conditions where spontaneous attention and attention directed to right or left-ear are tested while walking. We calculated dual-task costs (DTCs) and percent of baseline values for three spatio-temporal gait parameters as compared to single-walking during three DL conditions. Results showed that both groups had larger DTCs on gait during volitional control of attention, i.e., directing attention to one specific ear. Group differences were present across all DL conditions where older adults reported consistently less correct stimuli than younger participants. Similar findings were observed in the neuropsychological battery where older participants showed restricted abilities for executive functioning and processing speed. However, the main finding of this investigation was that younger adults exhibited unique adjustments in step length variability as shown by changes in DTCs and percent of baseline values. Particularly, an asymmetric effect was observed on the young group when attending right-ear stimuli. We interpreted this gait asymmetry as a compensatory outcome in the younger participants due to their optimal perceptual and motor abilities, which allow them to cope suitably with the dual-task situation. Many studies suggest that gait asymmetries are indicators of pathology, the present data demonstrate that gait asymmetries arise under specific constraints in healthy people as an adaptation to task requirements.

A 10-week yoga practice has no effect on cognition, but improves balance and motor learning by attenuating brain-derived neurotrophic factor levels in older adults.

Despite studies investigating the effect of yoga on cognitive and motor functioning in older adults, the effect on dual-task performance and motor learning and the specific mechanisms underlying the positive effect of yoga remain unclear. Thus, the aim of this study was to investigate the effects of yoga on cognition, balance under single- and dual-task conditions, and motor learning. The potential role of brain-derived neurotrophic factor (BDNF) in induced improvement was also explored. Participants aged 60-79 years were randomized to either a control group (n = 15) or a yoga group (n = 18) for a 10-week period. The yoga group received 90-min duration yoga classes two times per week. Changes in cognition, balance under single- and dual-task conditions, and learning fast and accurate reaching movements were assessed. Yoga practice decreased (P < 0.05) the velocity vector of the center of pressure under single- and dual-task conditions, whereas no changes in cognitive performance were observed. Although reaction and movement times during learning were decreased in both groups (P < 0.05), a faster reaction time (P < 0.05) and shorter movement time (P < 0.05) were observed in the yoga group than in the control group. Significant moderate relationships (P < 0.05) between changes in BDNF levels and functional improvements were observed. Thus, 10 weeks of yoga practice resulted in improved balance and learning in the speed-accuracy motor task that were mediated by increased BDNF levels, but had no impact on cognition in older adults.

Effects of a Rhodiola rosea extract on mental resource allocation and attention: An event-related potential dual task study.

Rhodiola rosea extract is widely used to alleviate stress and improve cognition and mental resources. A total of 50 adult participants were treated with 2 × 200 mg R. rosea extract (Rosalin®, WS® 1,375) for 12 weeks and were subjected to a neuropsychological test battery as well as an event-related brain potential measurement in a dual task paradigm prior to administration, after 6 weeks and after 12 weeks. The study followed a single-arm open-label design. Reaction times improved for the attention network task (ANT), the Go/Nogo task, and the divided attention task. Moreover, the orienting effect and the executive effect in the ANT showed an improvement. The P3 component in a dual task paradigm was increased in amplitude. The results of this pilot study show an improvement of mental speed and moreover, suggest improved mental resources. As the current study is single-armed these findings need to be replicated in a double-blind placebo controlled study.