Concussion can increase the risk of visually induced motion sickness.

Concussion can lead to various symptoms such as balance problems, memory impairments, dizziness, and/or headaches. It has been previously suggested that during self-motion relevant tasks, individuals with concussion may rely heavily on visual information to compensate for potentially less reliable vestibular inputs and/or problems with multisensory integration. As such, concussed individuals may also be more sensitive to other visually-driven sensations such as visually induced motion sickness (VIMS). To investigate whether concussed individuals are at elevated risk of experiencing VIMS, we exposed participants with concussion (n = 16) and healthy controls (n = 15) to a virtual scene depicting visual self-motion down a grocery store aisle at different speeds. Participants with concussion were further separated into symptomatic and asymptomatic groups. VIMS was measured with the SSQ before and after stimulus exposure, and visual dependence, self-reported dizziness, and somatization were recorded at baseline. Results showed that concussed participants who were symptomatic demonstrated significantly higher SSQ scores after stimulus presentation compared to healthy controls and those who were asymptomatic. Visual dependence was positively correlated with the level of VIMS in healthy controls and participants with concussion. Our results suggest that the presence of concussion symptoms at time of testing significantly increased the risk and severity of VIMS. This finding is of relevance with regards to the use of visual display devices such as Virtual Reality applications in the assessment and rehabilitation of individuals with concussion.

Machine learning algorithms for detection of visuomotor neural control differences in individuals with PASC and ME.

The COVID-19 pandemic has affected millions worldwide, giving rise to long-term symptoms known as post-acute sequelae of SARS-CoV-2 (PASC) infection, colloquially referred to as long COVID. With an increasing number of people experiencing these symptoms, early intervention is crucial. In this study, we introduce a novel method to detect the likelihood of PASC or Myalgic Encephalomyelitis (ME) using a wearable four-channel headband that collects Electroencephalogram (EEG) data. The raw EEG signals are processed using Continuous Wavelet Transform (CWT) to form a spectrogram-like matrix, which serves as input for various machine learning and deep learning models. We employ models such as CONVLSTM (Convolutional Long Short-Term Memory), CNN-LSTM, and Bi-LSTM (Bidirectional Long short-term memory). Additionally, we test the dataset on traditional machine learning models for comparative analysis. Our results show that the best-performing model, CNN-LSTM, achieved an accuracy of 83%. In addition to the original spectrogram data, we generated synthetic spectrograms using Wasserstein Generative Adversarial Networks (WGANs) to augment our dataset. These synthetic spectrograms contributed to the training phase, addressing challenges such as limited data volume and patient privacy. Impressively, the model trained on synthetic data achieved an average accuracy of 93%, significantly outperforming the original model. These results demonstrate the feasibility and effectiveness of our proposed method in detecting the effects of PASC and ME, paving the way for early identification and management of the condition. The proposed approach holds significant potential for various practical applications, particularly in the clinical domain. It can be utilized for evaluating the current condition of individuals with PASC or ME, and monitoring the recovery process of those with PASC, or the efficacy of any interventions in the PASC and ME populations. By implementing this technique, healthcare professionals can facilitate more effective management of chronic PASC or ME effects, ensuring timely intervention and improving the quality of life for those experiencing these conditions.

Sex differences in the neural underpinnings of unimanual and bimanual control in adults.

While many of the movements we make throughout our day involve just one upper limb, most daily movements require a certain degree of coordination between both upper limbs. Historically, sex differences in eye-hand coordination have been observed. As well, there are demonstrated sex-specific differences in hemisphere symmetry, interhemispheric connectivity, and motor cortex organization. While it has been suggested that these anatomical differences may underlie sex-related differences in performance, sex differences in the functional neural correlate underlying bimanual performance have not been explicitly investigated. In the current study we tested the hypothesis that the functional connectivity underlying bimanual movement control differed depending on the sex of an individual. Participants underwent MRI scanning to acquire anatomical and functional brain images. During the functional runs, participants performed unimanual and bimanual coordination tasks using two button boxes. The tasks included pressing the buttons in time to an auditory cue with either their left or their right hand individually (unimanual), or with both hands simultaneously (bimanual). The bimanual task was further divided into either an in-phase (mirror/symmetrical) or anti-phase (parallel/asymmetrical) condition. Participants were provided with extensive training to ensure task comprehension, and performance error rates were found to be equivalent between men and women. A generalized psychophysiological interaction (gPPI) analysis was implemented to examine how functional connectivity in each condition was modulated by sex. In support of our hypothesis, women and men demonstrated differences in the neural correlates underlying unimanual and bimanual movements. In line with previous literature, functional connectivity patterns showed sex-related differences for right- vs left-hand movements. Sex-specific functional connectivity during bimanual movements was not a sum of the functional connectivity underlying right- and left-hand unimanual movements. Further, women generally showed greater interhemispheric functional connectivity across all conditions compared to men and had greater connectivity between task-related cortical areas, while men had greater connectivity involving the cerebellum. Sex differences in brain connectivity were associated with both unimanual and bimanual movement control. Not only do these findings provide novel insight into the fundamentals of how the brain controls bimanual movements in both women and men, they also present potential clinical implications on how bimanual movement training used in rehabilitation can best be tailored to the needs of individuals.

Cortical and cerebellar structural correlates of cognitive-motor integration performance in females with and without persistent concussion symptoms.

INTRODUCTION: Fifteen percent of individuals who sustain a concussion develop persistent concussion symptoms (PCS). Recent literature has demonstrated atrophy of the frontal, parietal, and cerebellar regions following acute concussive injury. The frontoparietal-cerebellar network is essential for the performance of visuomotor transformation tasks requiring cognitive-motor integration (CMI), important for daily function. PURPOSE: We investigated cortical and subcortical structural differences and how these differences are associated with CMI performance in those with PCS versus healthy controls. METHODS: Twenty-six age-matched  female participants (13 PCS, 13 healthy) completed four visuomotor tasks.  Additionally, MR-images were analyzed for cortical thickness and volume, and cerebellar lobule volume. RESULTS: No statistically significant group differences were found in CMI performance. However, those with PCS demonstrated a significantly thicker and larger precuneus, and significantly smaller cerebellar lobules (VIIIa, VIIIb, X) compared to controls. When groups were combined, volumes of both the cerebellar lobules and cortical regions were associated with CMI task performance. CONCLUSION: The lack of behavioral differences combined with the structural differences may reflect a compensatory mechanism for those with PCS. In addition, this study highlights the effectiveness of CMI tasks in estimating the structural integrity of the frontoparietal-cerebellar network and is among the first to demonstrate structural correlates of PCS.

Differences in resting state functional connectivity underlie visuomotor performance declines in older adults with a genetic risk (APOE ε4) for Alzheimer's disease.

Introduction: Non-standard visuomotor integration requires the interaction of large networks in the brain. Previous findings have shown that non-standard visuomotor performance is impaired in individuals with specific dementia risk factors (family history of dementia and presence of the APOE ε4 allele) in advance of any cognitive impairments. These findings suggest that visuomotor impairments are associated with early dementia-related brain changes. The current study examined the underlying resting state functional connectivity (RSFC) associated with impaired non-standard visuomotor performance, as well as the impacts of dementia family history, sex, and APOE status. Methods: Cognitively healthy older adults (n = 48) were tested on four visuomotor tasks where reach and gaze were increasingly spatially dissociated. Participants who had a family history of dementia or the APOE ε4 allele were considered to be at an increased risk for AD. To quantify RSFC within networks of interest, an EPI sequence sensitive to BOLD contrast was collected. The networks of interest were the default mode network (DMN), somatomotor network (SMN), dorsal attention network (DAN), ventral attention network (VAN), and frontoparietal control network (FPN). Results: Individuals with the ε4 allele showed abnormalities in RSFC between posterior DMN nodes that predicted poorer non-standard visuomotor performance. Specifically, multiple linear regression analyses revealed lower RSFC between the precuneus/posterior cingulate cortex and the left inferior parietal lobule as well as the left parahippocampal cortex. Presence of the APOE ε4 allele also modified the relationship between mean DAN RSFC and visuomotor control, where lower mean RSFC in the DAN predicted worse non-standard visuomotor performance only in APOE ε4 carriers. There were otherwise no effects of family history, APOE ε4 status, or sex on the relationship between RSFC and visuomotor performance for any of the other resting networks. Conclusion: The preliminary findings provide insight into the impact of APOE ε4-related genetic risk on neural networks underlying complex visuomotor transformations, and demonstrate that the non-standard visuomotor task paradigm discussed in this study may be used as a non-invasive, easily accessible assessment tool for dementia risk.

Sex-related differences in visuomotor skill recovery following concussion in working-aged adults.

BACKGROUND: The ability to perform visually-guided motor tasks requires the transformation of visual information into programmed motor outputs. When the guiding visual information does not align spatially with the motor output, the brain processes rules to integrate somatosensory information into an appropriate motor response. Performance on such rule-based, "cognitive-motor integration" tasks is affected in concussion. Here, we investigate the relationship between visuomotor skill performance, concussion history, and sex during the course of a post-concussion management program. METHODS: Fifteen acutely concussed working-aged adults, 11 adults with a history of concussion, and 17 healthy controls all completed a recovery program over the course of 4 weeks. Prior to, mid-way, and following the program, all participants were tested on their visuomotor skills. RESULTS: We observed an overall change in visuomotor behaviour in all groups, as participants completed the tasks faster and more accurately. Specifically, we observed significant visuomotor skill improvement between the first and final sessions in participants with a concussion history compared to no-concussion-history controls. Notably, we observed a stronger recovery of these skills in females. CONCLUSIONS: Our findings indicate that (1) concussion impairs visuomotor skill performance, (2) the performance of complex, rule-based tasks showed improvement over the course of a recovery program, and (3) stronger recovery in females suggests sex-related differences in the brain networks controlling skilled performance, and the effect of injury on these networks.

Differences in structural MRI and diffusion tensor imaging underlie visuomotor performance declines in older adults with an increased risk for Alzheimer's disease.

Introduction: Visuomotor impairments have been demonstrated in preclinical AD in individuals with a positive family history of dementia and APOE e4 carriers. Previous behavioral findings have also reported sex-differences in performance of visuomotor tasks involving a visual feedback reversal. The current study investigated the relationship between grey and white matter changes and non-standard visuomotor performance, as well as the effects of APOE status, family history of dementia, and sex on these brain-behavior relationships. Methods: Older adults (n = 49) with no cognitive impairments completed non-standard visuomotor tasks involving a visual feedback reversal, plane-change, or combination of the two. Participants with a family history of dementia or who were APOE e4 carriers were considered at an increased risk for AD. T1-weighted anatomical scans were used to quantify grey matter volume and thickness, and diffusion tensor imaging measures were used to quantify white matter integrity. Results: In APOE e4 carriers, grey and white matter structural measures were associated with visuomotor performance. Regression analyses showed that visuomotor deficits were predicted by lower grey matter thickness and volume in areas of the medial temporal lobe previously implicated in visuomotor control (entorhinal and parahippocampal cortices). This finding was replicated in the diffusion data, where regression analyses revealed that lower white matter integrity (lower FA, higher MD, higher RD, higher AxD) was a significant predictor of worse visuomotor performance in the forceps minor, forceps major, cingulum, inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and uncinate fasciculus (UF). Some of these tracts overlap with those important for visuomotor integration, namely the forceps minor, forceps major, SLF, IFOF, and ILF. Conclusion: These findings suggest that measuring the dysfunction of brain networks underlying visuomotor control in early-stage AD may provide a novel behavioral target for dementia risk detection that is easily accessible, non-invasive, and cost-effective. The results also provide insight into the structural differences in inferior parietal lobule that may underlie previously reported sex-differences in performance of the visual feedback reversal task.

Sabotage Detection Using DL Models on EEG Data From a Cognitive-Motor Integration Task.

Objective clinical tools, including cognitive-motor integration (CMI) tasks, have the potential to improve concussion rehabilitation by helping to determine whether or not a concussion has occurred. In order to be useful, however, an individual must put forth their best effort. In this study, we have proposed a novel method to detect the difference in cortical activity between best effort (no-sabotage) and willful under-performance (sabotage) using a deep learning (DL) approach on the electroencephalogram (EEG) signals. The EEG signals from a wearable four-channel headband were acquired during a CMI task. Each participant completed sabotage and no-sabotage conditions in random order. A multi-channel convolutional neural network with long short term memory (CNN-LSTM) model with self-attention has been used to perform the time-series classification into sabotage and no-sabotage, by transforming the time-series into two-dimensional (2D) image-based scalogram representations. This approach allows the inspection of frequency-based, and temporal features of EEG, and the use of a multi-channel model facilitates in capturing correlation and causality between different EEG channels. By treating the 2D scalogram as an image, we show that the trained CNN-LSTM classifier based on automated visual analysis can achieve high levels of discrimination and an overall accuracy of 98.71% in case of intra-subject classification, as well as low false-positive rates. The average intra-subject accuracy obtained was 92.8%, and the average inter-subject accuracy was 86.15%. These results indicate that our proposed model performed well on the data of all subjects. We also compare the scalogram-based results with the results that we obtained by using raw time-series, showing that scalogram-based gave better performance. Our method can be applied in clinical applications such as baseline testing, assessing the current state of injury and recovery tracking and industrial applications like monitoring performance deterioration in workplaces.

Blast in Context: The Neuropsychological and Neurocognitive Effects of Long-Term Occupational Exposure to Repeated Low-Level Explosives on Canadian Armed Forces' Breaching Instructors and Range Staff.

Currently, there is strong interest within the military to better understand the effects of long-term occupational exposure to repeated low-level blast on health and performance. To gain traction on the chronic sequelae of blast, we focused on breaching-a tactical technique for gaining entry into closed/blocked spaces by placing explosives and maintaining a calculated safe distance from the detonation. Using a cross-sectional design, we compared the neuropsychological and neurocognitive profiles of breaching instructors and range staff to sex- and age-matched Canadian Armed Forces (CAF) controls. Univariate tests demonstrated that breaching was associated with greater post-concussive symptoms (Rivermead Post Concussion Symptoms Questionnaire) and lower levels of energy (RAND SF-36). In addition, breaching instructors and range staff were slower on a test that requires moving and thinking simultaneously (i.e., cognitive-motor integration). Next, using a multivariate approach, we explored the impact of other possible sources of injury, including concussion and prior war-zone deployment on the same outcomes. Concussion history was associated with higher post-concussive scores and musculoskeletal problems, whereas deployment was associated with higher post-concussive scores, but lower energy and greater PTSD symptomatology (using PCL-5). Our results indicate that although breaching, concussion, and deployment were similarly correlated with greater post-concussive symptoms, concussion history appears to be uniquely associated with altered musculoskeletal function, whereas deployment history appears to be uniquely associated with lower energy and risk of PTSD. We argue that the broader injury context must, therefore, be considered when studying the impact of repetitive low-level explosives on health and performance in military members.

The Effects of Mild Traumatic Brain Injury on Cognitive-Motor Integration for Skilled Performance.

Adults exposed to blast and blunt impact often experience mild traumatic brain injury, affecting neural functions related to sensory, cognitive, and motor function. In this perspective article, we will review the effects of impact and blast exposure on functional performance that requires the integration of these sensory, cognitive, and motor control systems. We describe cognitive-motor integration and how it relates to successfully navigating skilled activities crucial for work, duty, sport, and even daily life. We review our research on the behavioral effects of traumatic impact and blast exposure on cognitive-motor integration in both younger and older adults, and the neural networks that are involved in these types of skills. Overall, we have observed impairments in rule-based skilled performance as a function of both physical impact and blast exposure. The extent of these impairments depended on the age at injury and the sex of the individual. It appears, however, that cognitive-motor integration deficits can be mitigated by the level of skill expertise of the affected individual, suggesting that such experience imparts resiliency in the brain networks that underly the control of complex visuomotor performance. Finally, we discuss the next steps needed to comprehensively understand the impact of trauma and blast exposure on functional movement control.

Assessment of a Cognitive-Motor Training Program in Adults at Risk for Developing Dementia.

BACKGROUND: With the prevalence of dementia increasing each year, pre-clinically implemented therapeutic interventions are needed. It has been suggested that cascading neural network failures may bring on behavioural deficits associated with Alzheimer's disease. METHODS: Previously we have shown that cognitive-motor integration (CMI) training in adults with cognitive impairments generalized to improved global cognitive and activities of daily living scores. Here we employ a novel movement control-based training approach involving CMI rather than traditional cognition-only brain training. We hypothesized that such training would stimulate widespread neural networks and enhance rule-based visuomotor ability in at-risk individuals. RESULTS: We observed a significant improvement in bimanual coordination in the at-risk training group. We also observed significant decreases in movement variability for the most complex CMI condition in the at-risk and healthy training groups. CONCLUSIONS: These data suggest that integrating cognition into action in a training intervention may be effective at strengthening vulnerable brain networks in asymptomatic adults at risk for developing dementia.

Motor Deficits in Youth with Concussion History: Issues with Task Novelty or Task Demand?

The present study expands previous work on eye-hand decoupling deficits in youth with concussion history. It examines whether deficits can be linked to difficulties adapting to new task constraints or meeting ongoing task demands. Data from 59 youth with concussion history (M=11 months post-concussion) and 55 no history controls were analyzed. All 114 participants (M=12.5 yrs.) performed two touchscreen-based eye-hand coordination tasks: A standard task with vision and motor action in alignment, and an eye-hand decoupling task with both spatially decoupled, with twenty trials per task condition. First (trial 1-4), middle (trial 9-12), and last (trial 17-20) trial blocks were analyzed in each condition across groups, as well as first and last blocks only. The latter analysis showed in the first block longer response times in the concussion history group in the eye-hand decoupling condition due to a general slowdown of the reaction times across blocks and a trend for higher movement times. Our findings suggest that youth with concussion history have difficulty to adapt to new task constraints associated with complex skill performance during a short series of trials. These results are relevant for athletic trainers, therapists and coaches who work with youth with concussion history.

White Matter Integrity and Its Relationship to Cognitive-Motor Integration in Females with and without Post-Concussion Syndrome.

Fifteen percent of individuals who sustain a concussion go on to develop post-concussion syndrome (PCS). These persistent symptoms are believed to be attributed to damage to white matter tracts and impaired neurotransmission. Specifically, declines in white matter integrity after concussion have been found along the long-coursing axons underlying the frontoparietal network. This network is essential for the performance of visuomotor transformation tasks requiring cognitive-motor integration (CMI). We have previously observed deficits in performance on CMI-based tasks in those who have a history of concussion, but were asymptomatic. The aim of this study was to investigate performance on a CMI task, as well as white matter integrity differences along frontoparietal-cerebellar white matter tracts, in those with PCS compared to healthy controls. We hypothesized an association between the behavioral and brain structural measures. Twenty-six female participants (13 with PCS for ≥6 months and 13 healthy controls) completed four computer-based visuomotor CMI tasks. In addition, diffusion tensor images (DTIs) were acquired. No statistically significant differences were found in CMI performance between groups (p > 0.05). Further, there were no statistically significant differences between groups on any DTI metrics (p > 0.05). However, examination of the data collapsed across participants revealed significant associations between performance on a CMI task and white matter integrity. Further investigation into additional causes of symptoms in those with PCS (including psychological and cervicogenic factors) will strengthen our understanding of this diverse group. Nonetheless, this study demonstrates that white matter integrity is related to levels of performance in tasks that require rule-based movement control.

Group format rehabilitation is equally effective as individual therapy in patients with surgically repaired rotator cuff tears.

OBJECTIVE: Does group physiotherapy methods produce different results when compared with individual physiotherapy in persons with surgically repaired rotator cuff tears? No studies to date have examined the feasibility or effectiveness of such therapy formats. Given the prevalence of rotator cuff tears, a study examining group format therapy is warranted and can produce evidence to transform care for rotator cuff tear rehabilitation. METHODS: We analyzed the electronic medical records of persons that underwent rotator cuff repair surgery followed by the prescribedpost-surgical physiotherapy at Southlake Regional Health Centre. Both groups were provided standard physiotherapy intervention protocol for post-operative rotator cuff tear. Active range of motion (AROM), quick disabilities of the arm, shoulder and hand (Q-DASH) measures, and efficiency measures were examined for differences between groups. RESULTS: No significant differences between AROM (abduction p = .92, lateral rotation p = .64, and flexion p = 1.00) and Q-DASH (p = .62) measures between groups were observed at discharge. Overall, group therapy participants required a greater number of visits (p = .000); however, when separated by age groups, only the 60- to 69-year-old participants significantly differed in number of visits between groups (p = .000), whereas no difference was observed in the 50- to 59-year-old participants (p = .14). CONCLUSION: Group format physiotherapy may be equally effective as individual formats in improving AROM and functional outcomes of participants with surgically repaired rotator cuff tears. Further research is needed to determine the optimal age range for group therapy interventions in this population.

Remote concussion history does not affect visually-guided reaching in young adult females.

AIM: We examined the long-term effects of concussions in young adult females on visuomotor behavior during a visually-guided reaching task of various complexities. MATERIALS & METHODS: 20 females with a history of longer than 6 months since a concussion and 20 healthy females quickly and accurately performed a delayed reach to a previously cued target. RESULTS: As both cognitive and motor load increased, task performance decreased for both groups (p < 0.05). However, contrary to our primary hypothesis, no differences in task performance were found between the two experimental groups (p > 0.05). CONCLUSION: The young adult females with a remote history of concussion demonstrated no deficits in visuomotor behavior on an attention-mediated reaching task as compared with control participants.

Cognitive-Motor Integration Performance Is Affected by Sex, APOE Status, and Family History of Dementia.

BACKGROUND: Cognitive-motor integration (CMI) involves concurrent thought and action which requires the interaction of large brain networks. Given that early-stage dementia involves neural network dysfunction, deficits in CMI may prove useful for early dementia detection. OBJECTIVE: Our research objective was to investigate sex-related differences in the ability to integrate rules into action. METHODS: Based on family medical history, we recruited male and female participants both with and without dementia risk factors. Participants did not demonstrate cognitive impairment at the time of testing. Participants were tested on four increasingly dissociated visuomotor tasks (eye and hand movements were made in different spatial planes and/or visual feedback was reversed). RESULTS: We observed significantly greater hand movement endpoint error scores and corrective path lengths in at-risk females compared to at-risk males in the most complex CMI condition (plane-change + feedback reversal). Multiple regression analyses revealed both sex and family history as significant predictors of worse performance in a CMI condition requiring visual feedback reversal. Further, the regression analyses provided preliminary evidence that having an APOEɛ4 allele was a significant predictor of poorer CMI performance in the two plane-change CMI conditions. CONCLUSION: These data suggest that underlying brain networks controlling simultaneous thought and action may differ between the sexes in ways that may be clinically relevant in dementia progression. Preliminary data also suggest an important connection between APOE variant and CMI performance in individuals at risk of developing dementia.

Sport experience is correlated with complex motor skill recovery in youth following concussion.

A previous study showed prolonged cognitive-motor integration (CMI) deficits in youth with a history of concussion who were classified as asymptomatic by current return-to-play protocols, highlighting potential differences between clinical symptom recovery and skill recovery. The present study examines factors that may influence skilled performance recovery (defined as matching the skill level of no-concussion history peers) post-concussion in a similar cohort. Sixty-four asymptomatic youth (M = 13 yrs.) soccer, hockey, and lacrosse players with a concussion history (M = 14 months post-concussion) who returned to play and sixty-two age-matched team members with no previous concussion participated in this study. They performed two touchscreen-based eye-hand coordination tasks, including a direct interaction and a CMI task. We analysed the relationship between CMI performance and concussion history, and whether age, sex, number of concussions, and years of sport experience in their sport affected skill recovery. Individuals with concussion history and higher amounts of sport experience (7-12 years) reached a performance level matching their no-history peers quicker (after 12 months) than those with concussion history and lower sport experience (1-6 years; recovery after 30 months). This effect was independent of the number of concussions, age, and sex. The present results point towards an important role of eye-limb coordination-related sport experience in functional CMI recovery post-concussion. Youth with a concussion history but greater sport experience may have more skill-related motor "reserve". This reserve may directly aid in behavioural recovery post-concussion, or the greater neurological efficiency associated with athletic experience provides a compensatory mechanism that provides faster functional recovery.

Development of rule-based eye-hand-decoupling in children and adolescents.

In the present study, we characterize how the ability to decouple guiding visual information from a motor action emerges during childhood and adolescence. Sixty-two participants (age range 8-15 yrs.) completed two eye-hand coordination tasks. In a direct interaction task, vision and motor action were in alignment, and participants slid their finger along a vertical touch screen to move a cursor from a central target to one of four peripheral targets. In an eye-hand-decoupled task, eye and hand movements were made in different planes and cursor feedback was 180° reversed. We analyzed whether movement planning, timing and trajectory variables differed across age in both task conditions. There were no significant relationships between age and any movement planning, timing, or execution variables in the direct interaction task. In contrast, in the eye-hand-decoupled task, we found a relationship between age and several movement planning and timing variables. In adolescents (13-15 yrs.), movement planning and timing was significantly shorter than that of young children (8-10 yrs.). Eye-hand-decoupled maturation emerged mainly during late childhood (11-12 yrs.). Notably, we detected performance differences between young children and adolescents exclusively during the eye-hand decoupling task which required the integration of rule-based cognitive information into the motor action. Differences were not observed during the direct interaction task. Our results quantify an important milestone for eye-hand-decoupling development in late childhood, leading to improved rule-based motor performance in early adolescence. This eye-hand-decoupling development may be due to frontal lobe development linked to rule-based behavior and the strengthening of fronto-parietal networks.

Looking up while reaching out: the neural correlates of making eye and arm movements in different spatial planes.

Standard visually guided reaching begins with foveation of a target of interest followed by an arm movement to the same spatial location. However, many visually guided arm movements, as well as a majority of imaging studies examining such movements, require participants to perform non-standard visuomotor mappings where the locations of gaze and arm movements are spatially dissociated (e.g. gaze fixation peripheral to the target of a reaching movement, or use of a tool such as a joystick while viewing stimuli on a screen). In this study, we compare brain activity associated with the production of standard visually guided arm movements to activity during a visuomotor mapping where saccades and reaches were made in different spatial planes. Multi-voxel pattern analysis revealed that while spatial patterns of voxel activity remain quite similar for the two visuomotor mappings during presentation of a cue for movement, patterns of activity become increasingly more discriminative throughout the brain as planning progresses toward motor execution. Decoding of the visuomotor mappings occurs throughout visuomotor-related regions of the brain including the premotor, primary motor and somatosensory, posterior parietal, middle occipital, and medial occipital cortices, and in the cerebellum. These results show that relative to standard visuomotor tasks, activity differs substantially in areas throughout the brain when a task requires an implicit sensorimotor recalibration.

Thinking-While-Moving Exercises May Improve Cognition in Elderly with Mild Cognitive Deficits: A Proof-of-Principle Study.

BACKGROUND: Noninvasive interventions to aid healthy cognitive aging are considered an important healthcare priority. Traditional approaches typically focus on cognitive training or aerobic exercise training. In the current study, we investigate the effect of exercises that directly combine cognitive and motor functions on visuomotor skills and general cognition in elderly with various degrees of cognitive deficits. SUBJECTS AND METHODS: A total of 37 elderly, divided into four groups based on their level of cognition, completed a 16-week cognitive-motor training program. The weekly training sessions consisted of playing a videogame requiring goal-directed hand movements on a computer tablet for 30 minutes. Before and after the training program, all participants completed a test battery to establish their level of cognition and visuomotor skills. RESULTS: We observed an overall change in visuomotor behavior in all groups, as participants completed the tasks faster but less accurately. More importantly, we observed a significant improvement in measures of overall cognition in the subaverage cognition group and the mild-to-moderate cognitive deficits group. CONCLUSION: Our findings indicate that (1) cognitive-motor exercises induce improved test scores, which is most prominent in elderly with only mild cognitive deficits, and (2) cognitive-motor exercises induce altered visuomotor behavior and slight improvements in measures of general cognition.