Exergames Inherently Contain Cognitive Elements as Indicated by Cortical Processing

A Metamaterial Computational Multi-Sensor of Grip-Strength Properties with Point-of-Care Human-Computer Interaction

Grip strength is a biomarker of frailty and an evaluation indicator of brain health, cardiovascular morbidity, and psychological health. Yet, the development of a reliable, interactive, and point-of-care device for comprehensive multi-sensing of hand grip status is challenging. Here, a relation between soft buckling metamaterial deformations and built piezoelectric voltage signals is uncovered to achieve multiple sensing of maximal grip force, grip speed, grip impulse, and endurance indicators. A metamaterial computational sensor design is established by hyperelastic model that governs the mechanical characterization, machine learning models for computational sensing, and graphical user interface to provide visual cues. A exemplify grip measurement for left and right hands of seven elderly campus workers is conducted. By taking indicators of grip status as input parameters, human-computer interactive games are incorporated into the computational sensor to improve the user compliance with measurement protocols. Two elderly female schizophrenic patients are participated in the real-time interactive point-of-care grip assessment and training for potentially sarcopenia screening. The attractive features of this advanced intelligent metamaterial computational sensing system are crucial to establish a point-of-care biomechanical platform and advancing the human-computer interactive healthcare, ultimately contributing to a global health ecosystem.

Mobile Electroencephalography Reveals Differences in Cortical Processing During Exercises With Lower and Higher Cognitive Demands in Preadolescent Children

PURPOSE

The aim of this study was to examine whether cortical activity changes during exercise with increasing cognitive demands in preadolescent children.

METHOD

Twenty healthy children (8.75 [0.91] y) performed one movement game, which was conducted with lower and higher cognitive demands. During a baseline measurement and both exercise conditions, cortical activity was recorded using a 64-channel electroencephalographic system, and heart rate was assessed. Ratings of perceived excertion and perceived cognitive engagement were examined after each condition. To analyze power spectral density in the theta, alpha-1, and alpha-2 frequency bands, an adaptive mixture independent component analysis was used to determine the spatiotemporal sources of cortical activity, and brain components were clustered to identify spatial clusters.

RESULTS

One-way repeated-measures analyses of variance revealed significant main effects for condition on theta in the prefrontal cluster, on alpha-1 in the prefrontal, central, bilateral motor, bilateral parieto-occipital, and occipital clusters, and on alpha-2 in the left motor, central, and left parieto-occipital clusters. Compared with the lower cognitive demand exercise, cortical activity was significantly higher in theta power in the prefrontal cluster and in alpha-1 power in the occipital cluster during the higher cognitive demand exercise.

CONCLUSION

The present study shows that exercise complexity seems to influence cortical processing as it increased with increasing cognitive demands.

Efficacy of a 6-week Novel Exergaming Intervention Guided by Heart Rate Zones on Aerobic Performance in Children with Fetal Alcohol Spectrum Disorder and Attention-deficit/Hyperactivity Disorder: A Feasibility Study

The purpose of this study was to determine the feasibility of a novel exergaming intervention guided by heart rate zones for children and adolescents with fetal alcohol spectrum disorder (FASD) and attention-deficit/hyperactivity disorder (ADHD). Eight study participants (6 females, 2 males, mean age= 11.4±1.4 years old) participated twice weekly over six weeks to complete twelve multimodal exergaming sessions. Participants significantly improved 6MWT from baseline to week 6 (575.4±55.0 m to 732.8±58.9 m; P<0.01), which conferred a 31% improvement in estimated VO2max (31.5±5.5 ml/kg/min to 40.9±5.9 ml/kg/min), respectively. There was an upward trend of the mean percentage of time spent in the intermediate HR zones over the course of the 6-week intervention. These findings may provide value to the field as they support the clinical utility and promising effects of cardiovascular improvement in children who engage in a compelling exergaming intervention. In doing so, this establishes a preliminary understanding of how to augment routine physical exercise through exergaming using visually targeted heart rate zones.

Reducing Visuospatial Pseudoneglect in Healthy Subjects by Active Video Gaming

Pseudoneglect phenomenon refers to a condition in which healthy subjects tend to perceive the left side of exactly bisected lines as being slightly longer than the right one. However, behavioural data showed that athletes practising an open-skill sport display less pseudoneglect than the general population. Given the fact that so-called exergames (also known as active video games) are platforms designed to fully mimic sport activity, this work intends to investigate whether and how a one-week training period of exergame open-skill sport can determine a similar decrease in pseudoneglect. Fifteen healthy participants (non-athletes) responded to a visuospatial attention task and a control memory task in basal conditions (t0: Pre-game) and after a short period (one week, one hour/day) of tennis exergaming (t1: Post-game). In the Post-game condition, subjects from this experimental group (ExerGame group: EG) reduced leftward space overestimation and made significantly fewer leftward errors compared to the Pre-game condition. Additionally, two other experimental groups were employed: one evaluated within the same conditions of the main experiment but using a non-exergame (Non-Exergame groups: NEG) and the other one without any video game stimulus (Sedentary group: SE). Our findings suggest that daily training of a tennis exergame seems to be able to improve visuospatial attention isotropy by reducing leftward space overestimation, whereas outcomes from non-exergaming and sedentary activity do not modify subjects' performance.

Effects of exergaming in older individuals with mild cognitive impairment and dementia: A systematic review and meta-analysis

BACKGROUND

Non-pharmaceutical interventions have been implemented for people with dementia or mild cognitive impairment (MCI). Researchers have used exergaming in dementia to alleviate cognitive decline in patients with dementia.

AIMS

We assessed the effects of exergaming interventions on MCI and dementia.

METHODS

We conducted a systematic review and meta-analysis (PROSPERO [CRD42022347399]). PubMed, Cochrane Library, Web of Science, CINAHL, and Embase electronic databases were searched for randomized controlled trials (RCTs). The impact of exergaming on cognitive function, physical performance, and quality of life in patients with MCI and dementia was investigated.

RESULTS

Ten RCTs met the eligibility criteria and were included in our systematic review. The results of the meta-analysis demonstrated a statistically significant difference in the Mini-mental State Examination, Montreal Cognitive Assessment, Trail Making Test, Chinese version of the Verbal Learning Test, Berg Balance Scale, Short Physical Performance Battery, and Physical Activity Scale for the Elderly in people with dementia and MCI who participated in exergaming. However, there were no significant improvements in the Activities of Daily Living, Instrumental Activity of Daily Living or Quality of Life.

CONCLUSION

Although there were significant differences in cognitive and physical functions, these results should be interpreted with caution because of heterogeneity. The additional benefits of exergaming remain to be confirmed in future studies.

Brain activation and single-limb balance following anterior cruciate ligament reconstruction

OBJECTIVE

To compare brain activity between individuals with anterior cruciate ligament reconstruction (ACLR) and controls during balance. To determine the influence of neuromodulatory interventions (external focus of attention [EF] and transcutaneous electrical nerve stimulation [TENS]) on cortical activity and balance performance.

METHODS

Individuals with ACLR (n = 20) and controls (n = 20) performed a single-limb balance task under four conditions: internal focus (IF), object-based-EF, target-based-EF, and TENS. Electroencephalographic signals were decomposed, localized, and clustered to generate power spectral density in theta and alpha-2 frequency bands.

RESULTS

Participants with ACLR had higher motor-planning (d = 0.5), lower sensory (d = 0.6), and lower motor activity (d = 0.4-0.8), while exhibiting faster sway velocity (d = 0.4) than controls across all conditions. Target-based-EF decreased motor-planning (d = 0.1-0.4) and increased visual (d = 0.2), bilateral sensory (d = 0.3-0.4), and bilateral motor (d = 0.4-0.5) activity in both groups compared to all other conditions. Neither EF conditions nor TENS changed balance performance.

CONCLUSIONS

Individuals with ACLR exhibit lower sensory and motor processing, higher motor planning demands, and greater motor inhibition compared to controls, suggesting visual-dependence and less automatic balance control. Target-based-EF resulted in favorable reductions in motor-planning and increases in somatosensory and motor activity, transient effects in line with impairments after ACLR.

SIGNIFICANCE

Sensorimotor neuroplasticity underlies balance deficits in individuals with ACLR. Neuromodulatory interventions such as focus of attention may induce favorable neuroplasticity along with performance benefits.

Exergaming in older adults: the effects of game characteristics on brain activity and physical activity

Introduction

Exergames are increasingly used in rehabilitation settings for older adults to train physical and cognitive abilities. To meet the potential that exergames hold, they need to be adapted to the individual abilities of the player and their training objectives. Therefore, it is important to know whether and how game characteristics affect their playing. The aim of this study is to investigate the effect of two different kinds of exergame (step game and balance game) played at two difficulty levels on brain activity and physical activity.

Methods

Twenty-eight older independently living adults played two different exergames at two difficulty levels each. In addition, the same movements as during gaming (leaning sideways with feet in place and stepping sideways) were performed as reference movements. Brain activity was recorded using a 64-channel EEG system to assess brain activity, while physical activity was recorded using an accelerometer at the lower back and a heart rate sensor. Source-space analysis was applied to analyze the power spectral density in theta (4 Hz-7 Hz) and alpha-2 (10 Hz-12 Hz) frequency bands. Vector magnitude was applied to the acceleration data.

Results

Friedman ANOVA revealed significantly higher theta power for the exergaming conditions compared to the reference movement for both games. Alpha-2 power showed a more diverse pattern which might be attributed to task-specific conditions. Acceleration decreased significantly from the reference movement to the easy condition to the hard condition for both games.

Discussion

The results indicate that exergaming increases frontal theta activity irrespective of type of game or difficulty level, while physical activity decreases with increasing difficulty level. Heart rate was found to be an inappropriate measure in this population older adults. These findings contribute to understanding of how game characteristics affect physical and cognitive activity and consequently need to be taken into account when choosing appropriate games and game settings for exergame interventions.

The effect of exergaming on cognition and brain activity in older adults: A motor- related cortical potential study

Exergames have positive effects on various cognitive domains. However, to the best of our knowledge, not only have few studies investigated the exergame-induced brain changes, but also in most of them, preparatory brain activity has not been considered. Preparatory brain activity is a particularly relevant aspect for investigating the interaction between cognitive and sensorimotor functions in the brain. Accordingly, the aim of this study was to investigate the effects of an exergame protocol versus traditional motor-cognitive dual-task training on the cognition and proactive components of movement-related cortical potential. A total of 52 older adults were randomly assigned to the intervention (exergame training) and the control group (motor-cognitive dual-task training). The outcome measurements were neurophysiological data (i.e., the amplitude of the late contingent negative variation [CNV], and alpha/beta event-related desynchronization [ERD]), and neuropsychological data (rate-correct score [RCS] in go/no go task and trail-making test [TMT]). The results revealed that both groups had a decreased late CNV, and alpha/ beta ERD in post-training compared to pre-training in Cz and C3 channels. Moreover, both groups had an increased RCS and a decreased TMT-A in post-training compared to pre-training. However, for TMT-B, the results indicated a significant interaction in favor of the exergame group. These findings indicate that in older adults, both interventions may result in increasing inhibitory control, information processing speed, and preparatory brain activity. However, for cognitive flexibility, exergame has an additional effect relative to the control group.

Usability of Two New Interactive Game Sensor-Based Hand Training Devices in Parkinson's Disease

This pilot cross-sectional study aimed to evaluate the usability of two new interactive game sensor-based hand devices (GripAble and Smart Sensor Egg) in both healthy adults as well as in persons with Parkinson's Disease (PD). Eight healthy adults and eight persons with PD participated in this study. Besides a standardised usability measure, the state of flow after one training session and the effect of cognitive abilities on flow were evaluated. High system usability scores (SUS) were obtained both in healthy participants (72.5, IQR = 64.375-90, GripAble) as well as persons with PD (77.5, IQR = 70-80.625, GripAble; 77.5, IQR = 75-82.5, Smart Sensor Egg). Similarly, high FSSOT scores were achieved after one training session (42.5, IQR = 39.75-50, GripAble; 50, IQR = 47-50, Smart Sensor Egg; maximum score 55). Across both groups, FSSOT scores correlated significantly with SUS scores (r = 0.52, p = 0.039). Finally, MoCA did not correlate significantly with FSSOT scores (r = 0.02, p = 0.9). The present study shows high usability for both interactive game sensor-based hand training devices, for persons with PD and healthy participants.

Continuous table tennis is associated with processing in frontal brain areas: an EEG approach

Coordinative challenging exercises in changing environments referred to as open-skill exercises seem to be beneficial on cognitive function. Although electroencephalographic research allows to investigate changes in cortical processing during movement, information about cortical dynamics during open-skill exercise is lacking. Therefore, the present study examines frontal brain activation during table tennis as an open-skill exercise compared to cycling exercise and a cognitive task. 21 healthy young adults conducted three blocks of table tennis, cycling and n-back task. Throughout the experiment, cortical activity was measured using 64-channel EEG system connected to a wireless amplifier. Cortical activity was analyzed calculating theta power (4–7.5 Hz) in frontocentral clusters revealed from independent component analysis. Repeated measures ANOVA was used to identify within subject differences between conditions (table tennis, cycling, n-back; p < .05). ANOVA revealed main-effects of condition on theta power in frontal (p < .01, η_p² = 0.35) and frontocentral (p < .01, η_p² = 0.39) brain areas. Post-hoc tests revealed increased theta power in table tennis compared to cycling in frontal brain areas (p < .05, d = 1.42). In frontocentral brain areas, theta power was significant higher in table tennis compared to cycling (p < .01, d = 1.03) and table tennis compared to the cognitive task (p < .01, d = 1.06). Increases in theta power during continuous table tennis may reflect the increased demands in perception and processing of environmental stimuli during open-skill exercise. This study provides important insights that support the beneficial effect of open-skill exercise on brain function and suggest that using open-skill exercise may serve as an intervention to induce activation of the frontal cortex.

The Effects of Health Consideration on Exergaming Behavior in College Students: A Structural Equation Perspective

Purpose: Exergaming play is associated with positive health benefits and increased engagement in physical activity outcomes in players. Research also indicates that factors such as enjoyment and entertainment drive users' exergame activities. However, despite advances in the area, little is known about whether health consideration and physical activity impact college students' exergaming behavior. Method: A cross-sectional online survey of open-ended and fixed questions was completed by 403 college students (Mage = 20.02, SD = 2.3; Range: 17-35; 73.2% female) from a large southwestern university. Descriptive analyses and structural equation modeling techniques were used to draw insights from the data. Results: Among the participants, nearly 87.6% of them reported participating in exergaming behavior. Both measurement and structural models showed good model fits. Health consideration (Std.β = .30, p < .01) and leisure-time physical activity (Std.β = .28, p < .01) were positively associated with exergaming behavior while health consideration was not significantly associated with leisure-time physical activity (Std.β = .05, p = .38). The mediation analysis revealed that the indirect effect from health consideration to exergaming behavior through leisure-time physical activity was not statistically significant (Std.β = .01, p = .38). Leisure-time physical activity could not mediate the relationship between health consideration and exergaming behavior. Conclusions: By pointing out the important role of health consideration and physical activity in college students' exergaming play, findings of this study can help exergame developers and gamification interventionists to design more effective programs and, in turn, facilitate positive intervention outcomes.

Somatosensory perturbations influence cortical activity associated with single-limb balance performance

To determine the association between cortical activity and postural control performance changes with differing somatosensory perturbations. Healthy individuals (n = 15) performed a single-limb balance task under four conditions: baseline, unstable surface (foam), transcutaneous electrical nerve stimulation (TENS) applied to the stance-limb knee, and combined foam + TENS. Cortical activity was recorded with electroencephalography (EEG) and postural sway via triaxial force plate. EEG signals were decomposed, localized, and clustered to generate power spectral density in theta (4-7 Hz) and alpha-2 (10-12 Hz) frequency bands in anatomical clusters. Postural sway signals were analyzed with center of pressure (COP) sway metrics (e.g., area, distance, velocity). Foam increased theta power in the frontal and central clusters (d = 0.77 to 1.16), decreased alpha-2 power in bilateral motor, right parietal, and occipital clusters (d =  - 0.89 to - 2.35) and increased sway area, distance, and velocity (d = 1.09-2.57) relative to baseline. Conversely, TENS decreased central theta power (d =  - 0.60), but increased bilateral motor, left parietal, and occipital alpha-2 power (d = 0.51-1.40), with similar to baseline balance performance. In combination, foam + TENS attenuated sway velocity detriments and cortical activity caused by the foam condition alone. There were weak and moderate associations between percent increased central theta and occipital activity and increased sway velocity. Somatosensory perturbations changed patterns of cortical activity during a single-limb balance task in a manner suggestive of sensory re-weighting to pertinent sensory feedback. Across conditions decreased cortical activity in pre-motor and visual regions were associated with reduced sway velocity.

Anterior Cruciate Ligament Reconstructed Patients Who Recovered Normal Postural Control Have Dissimilar Brain Activation Patterns Compared to Healthy Controls

Simple Summary

We report that patients with anterior cruciate ligament reconstruction have similar postural control but different cortical activation patterns in several regions of the brain when compared to healthy controls. This is significant because dissimilar cortical activation patterns indicate that neural adaptation in the brain is responsible for motor coordination, possibly due to altered proprioception, despite having a surgical reconstruction after an anterior cruciate ligament injury. Such neuroplasticity in ACLR patients may imply compensatory neural protective mechanisms in order to sustain postural control, which is a fundamental functional skill in daily activities. We believe that our findings will elucidate other researchers and clinicians about the effects of a peripheral joint injury on the brain’s function during postural control.

Abstract

Postural control, which is a fundamental functional skill, reflects integration and coordination of sensory information. Damaged anterior cruciate ligament (ACL) may alter neural activation patterns in the brain, despite patients’ surgical reconstruction (ACLR). However, it is unknown whether ACLR patients with normal postural control have persistent neural adaptation in the brain. Therefore, we explored theta (4–8 Hz) and alpha-2 (10–12 Hz) oscillation bands at the prefrontal, premotor/supplementary motor, primary motor, somatosensory, and primary visual cortices, in which electrocortical activation is highly associated with goal-directed decision-making, preparation of movement, motor output, sensory input, and visual processing, respectively, during first 3 s of a single-leg stance at two different task complexities (stable/unstable) between ACLR patients and healthy controls. We observed that ACLR patients showed similar postural control ability to healthy controls, but dissimilar neural activation patterns in the brain. To conclude, we demonstrated that ACLR patients may rely on more neural sources on movement preparation in conjunction with sensory feedback during the early single-leg stance period relative to healthy controls to maintain postural control. This may be a compensatory protective mechanism to accommodate for the altered sensory inputs from the reconstructed knee and task complexity. Our study elucidates the strategically different brain activity utilized by ACLR patients to sustain postural control.

Can Exergames Be Improved to Better Enhance Behavioral Adaptability in Older Adults? An Ecological Dynamics Perspective

Finding effective training solutions to attenuate the alterations of behavior and cognition in the growing number of older adults is an important challenge for Science and Society. By offering 3D computer-simulated environments to combine perceptual-motor and cognitive exercise, exergames are promising in this respect. However, a careful analysis of meta-analytic reviews suggests that they failed to be more effective than conventional motor-cognitive training. We analyzed the reasons for this situation, and we proposed new directions to design new, conceptually grounded, exergames. Consistent with the evolutionary neuroscience approach, we contend that new solutions should better combine high level of metabolic activity with (neuro)muscular, physical, perceptual-motor, and cognitive stimulations. According to the Ecological Dynamics rationale, we assume that new exergames should act at the agent-environment scale to allow individuals to explore, discover, and adapt to immersive and informationally rich environments that should include cognitively challenging tasks, while being representative of daily living situations.

Stance leg and surface stability modulate cortical activity during human single leg stance

Mobile Electroencephalography (EEG) provides insights into cortical contributions to postural control. Although changes in theta (4–8 Hz) and alpha frequency power (8–12 Hz) were shown to reflect attentional and sensorimotor processing during balance tasks, information about the effect of stance leg on cortical processing related to postural control is lacking. Therefore, the aim was to examine patterns of cortical activity during single-leg stance with varying surface stability. EEG and force plate data from 21 healthy males (22.43 ± 2.23 years) was recorded during unipedal stance (left/right) on a stable and unstable surface. Using source-space analysis, power spectral density was analyzed in the theta, alpha-1 (8–10 Hz) and alpha-2 (10–12 Hz) frequency bands. Repeated measures ANOVA with the factors leg and surface stability revealed significant interaction effects in the left (p = 0.045, η_p² = 0.13) and right motor clusters (F = 16.156; p = 0.001, η_p² = 0.41). Furthermore, significant main effects for surface stability were observed for the fronto-central cluster (theta), left and right motor (alpha-1), as well as for the right parieto-occipital cluster (alpha-1/alpha-2). Leg dependent changes in alpha-2 power may indicate lateralized patterns of cortical processing in motor areas during single-leg stance. Future studies may therefore consider lateralized patterns of cortical activity for the interpretation of postural deficiencies in unilateral lower limb injuries.

Acute effects of 2D exergame on cognitive functions and frontal cortical activity

ABSTRACT This study aims to evaluate the effect of an exercise with a 2D virtual reality session on the cognition and cortical activity of young males. This is a randomized controlled trial with ten men aged 18 to 23 years. They were randomly assigned under two conditions: 1) exercise session with 2D virtual reality games and 2) control, which consisted of watching a two-episode video of a comic TV show. Cognition and frontal cortical activity were assessed immediately before and after the intervention, using the Mindset, performing the Digit Span Test, semantic verbal fluency, and executive function. Executive function improved with the exergame session (p=0.025). Exergames partially promote an immediate increase in the executive function of young people.

Effects of exergames and cognitive-motor dual-task training on cognitive, physical and dual-task functions in cognitively healthy older adults: An overview

This overview aims to summarize the effectiveness of cognitive-motor dual-task and exergame interventions on cognitive, physical and dual-task functions in healthy older adults, as well as the feasibility, safety, adherence, transfer and retention of benefits of these interventions. We searched for systematic reviews or meta-analyses assessing the effects of cognitive-motor dual-task and exergame interventions on cognitive, physical and dual-task functions in cognitively healthy older adults through eight databases (CDSR (Cochrane), MEDLINE (PubMed), Scopus, EMBASE, CINAHL, PsycINFO, ProQuest and SportDiscus). Two reviewers performed the selection, data extraction and risk of bias evaluation independently (PROSPERO ID: CRD42019143185). Eighteen reviews were included in this overview. Overall, positive effects of cognitive-motor dual-task interventions on cognitive, physical and dual-task functions, as well as exergames on cognitive functions only, were observed in cognitively healthy older adults. In contrast, the effects of exergames on physical functions are more controversial, and their effects on dual-task functions have not been studied. The feasibility, safety, adherence, transfer and retention of benefits for both intervention types are still unclear. Future studies should follow more rigorous methodological standards in order to improve the quality of evidence and provide guidelines for the use of cognitive-motor dual-task and exergame interventions in older adults.

The influence of motor tasks and cut-off parameter selection on artifact subspace reconstruction in EEG recordings

Advances in EEG filtering algorithms enable analysis of EEG recorded during motor tasks. Although methods such as artifact subspace reconstruction (ASR) can remove transient artifacts automatically, there is virtually no knowledge about how the vigor of bodily movements affects ASRs performance and optimal cut-off parameter selection process. We compared the ratios of removed and reconstructed EEG recorded during a cognitive task, single-leg stance, and fast walking using ASR with 10 cut-off parameters versus visual inspection. Furthermore, we used the repeatability and dipolarity of independent components to assess their quality and an automatic classification tool to assess the number of brain-related independent components. The cut-off parameter equivalent to the ratio of EEG removed in manual cleaning was strictest for the walking task. The quality index of independent components, calculated using RELICA, reached a maximum plateau for cut-off parameters of 10 and higher across all tasks while dipolarity was largely unaffected. The number of independent components within each task remained constant, regardless of the cut-off parameter used. Surprisingly, ASR performed better in motor tasks compared with non-movement tasks. The quality index seemed to be more sensitive to changes induced by ASR compared to dipolarity. There was no benefit of using cut-off parameters less than 10. Graphical abstract The graphical abstract shows the three tasks performed during EEG recording, the two processing pipelines (manual and artifact subspace reconstruction), and the metrics the conclusion is based on.

Balance Training in Older Adults Using Exergames: Game Speed and Cognitive Elements Affect How Seniors Play

Falls in older adults are a serious threat to their health and independence, and a prominent reason for institutionalization. Incorrect weight shifts and poor executive functioning have been identified as important causes for falling. Exergames are increasingly used to train both balance and executive functions in older adults, but it is unknown how game characteristics affect the movements of older adults during exergaming. The aim of this study was to investigate how two key game elements, game speed, and the presence of obstacles, influence movement characteristics in older adults playing a balance training exergame. Fifteen older adults (74 ± 4.4 years) played a step-based balance training exergame, designed specifically for seniors to elicit weight shifts and arm stretches. The task consisted of moving sideways to catch falling grapes and avoid obstacles (falling branches), and of raising the arms to catch stationary chickens that appeared above the avatar. No steps in anterior-posterior direction were required in the game. Participants played the game for eight 2 min trials in total, at two speed settings and with or without obstacles, in a counterbalanced order across participants. A 3D motion capture system was used to capture position data of 22 markers fixed to upper and lower body. Calculated variables included step size, step frequency, single leg support, arm lift frequency, and horizontal trunk displacement. Increased game speed resulted in a decrease in mean single support time, step size, and arm lift frequency, and an increase in cadence, game score, and number of error messages. The presence of obstacles resulted in a decrease in single support ratio, step size, cadence, frequency of arm lifts, and game score. In addition, step size increased from the first to the second trial repetition. These results show that both game speed and the presence of obstacles influence players' movement characteristics, but only some of these effects are considered beneficial for balance training whereas others are detrimental. These findings underscore that an informed approach is necessary when designing exergames so that game settings contribute to rather than hinder eliciting the required movements for effective balance training.

Balance task difficulty affects postural sway and cortical activity in healthy adolescents

Electroencephalographic (EEG) research indicates changes in adults’ low frequency bands of frontoparietal brain areas executing different balance tasks with increasing postural demands. However, this issue is unsolved for adolescents when performing the same balance task with increasing difficulty. Therefore, we examined the effects of a progressively increasing balance task difficulty on balance performance and brain activity in adolescents. Thirteen healthy adolescents aged 16–17 year performed tests in bipedal upright stance on a balance board with six progressively increasing levels of task difficulty. Postural sway and cortical activity were recorded simultaneously using a pressure sensitive measuring system and EEG. The power spectrum was analyzed for theta (4–7 Hz) and alpha-2 (10–12 Hz) frequency bands in pre-defined frontal, central, and parietal clusters of electrocortical sources. Repeated measures analysis of variance (rmANOVA) showed a significant main effect of task difficulty for postural sway (p < 0.001; d = 6.36). Concomitantly, the power spectrum changed in frontal, bilateral central, and bilateral parietal clusters. RmANOVAs revealed significant main effects of task difficulty for theta band power in the frontal (p < 0.001, d = 1.80) and both central clusters (left: p < 0.001, d = 1.49; right: p < 0.001, d = 1.42) as well as for alpha-2 band power in both parietal clusters (left: p < 0.001, d = 1.39; right: p < 0.001, d = 1.05) and in the central right cluster (p = 0.005, d = 0.92). Increases in theta band power (frontal, central) and decreases in alpha-2 power (central, parietal) with increasing balance task difficulty may reflect increased attentional processes and/or error monitoring as well as increased sensory information processing due to increasing postural demands. In general, our findings are mostly in agreement with studies conducted in adults. Similar to adult studies, our data with adolescents indicated the involvement of frontoparietal brain areas in the regulation of postural control. In addition, we detected that activity of selected brain areas (e.g., bilateral central) changed with increasing postural demands.

Modulations of Inter-Hemispherical Phase Coupling in Human Single Leg Stance

INTRODUCTION

Recent findings from neuroimaging studies provided initial insights into cortical contributions to postural control. These studies observed enhanced cortical activation and connectivity when task-difficulty and postural instability increased. However, little attention has been paid to the allocation of cortical networks appearing with a decreasing base of support from bipedal to single leg stance. Therefore, the aim of the present study was to investigate modulations of functional connectivity from bipedal to single leg stance.

EXPERIMENTAL PROCEDURES

Cortical activity during bipedal and single leg stance (left) was investigated in 15 male subjects using 128 channel mobile electroencephalography (EEG), while standing on a triaxial force plate. Power spectral density was calculated for theta (4-7 Hz), alpha-1 (8-10 Hz) and alpha-2 (10-12 Hz) frequency bands. Estimations of the phase lag index (PLI) were conducted as a measure of functional connectivity. Moreover, postural control was analyzed by the area of sway and sway velocity.

RESULTS

The results demonstrated a significantly increased area of sway and decreased alpha-2 power in single leg compared to bipedal stance. Furthermore, PLIs within the alpha-2 frequency band showed significantly decreased inter-hemispherical phase coupling in single leg stance, associated with connections involving the left motor region.

DISCUSSION

Altogether, the present findings may indicate modulations of cortical contributions in single leg compared to bipedal stance. The present data suggest that decreased inter-hemispherical functional connectivity, in conjunction with a global increase in cortical excitability, may indicate enhanced alertness and task-specific selective inhibition of motor networks in favor of postural control.