Training-related Improvements Research Articles

The effects of working memory resource depletion and training on sensorimotor adaptation

We have recently demonstrated that visuospatial working memory performance predicts the rate of motor skill learning, particularly during the early phase of visuomotor adaptation. Here, we follow up these correlational findings with direct manipulations of working memory resources to determine the impact on visuomotor adaptation, a form of motor learning. We conducted two separate experiments. In the first one, we used a resource depletion strategy to investigate whether the rate of early visuomotor adaptation would be negatively affected by fatigue of spatial working memory resources. In the second study, we employed a dual n-back task training paradigm that has been shown to result in transfer effects [1] over five weeks to determine whether training-related improvements would boost the rate of early visuomotor adaptation. The depletion of spatial working memory resources negatively affected the rate of early visuomotor adaptation. However, enhancing working memory capacity via training did not lead to improved rates of visuomotor adaptation, suggesting that working memory capacity may not be the factor limiting maximal rate of visuomotor adaptation in young adults. These findings are discussed from a resource limitation/capacity framework with respect to current views of motor learning.

An Online Investigation of Face Training in a Large Sample of Developmental Prosopagnosics, Phase 1

Case studies over the last 5 years have shown it is possible to improve face processing in developmental prosopagnosics (DPs) through cognitive training. Though these studies are promising, it's unclear whether face processing can be improved in a larger sample of DPs. Moreover, these studies did not sufficiently characterize the real-world significance of training-related improvements. We attempted to address these issues by recruiting a larger sample of DPs to perform an intensive face training program (45 min/day for 15 days) aimed at improving configural/holistic processing of faces. This program has shown previous evidence of training-related improvements in individual cases (for example, see DeGutis, 2007). To increase our sample we had subjects perform testing and training on the web while being in close communication with the experimenter. The assessment battery consisted of tests of face perception, memory, part and whole processing, and object processing. We compared the pre and post results of the training group with a group of DPs that were assessed before and after a 15 day wait period. The training group also completed a diary for 5 days before and after training to quantify potential real-world improvements. We found that, as a group, DPs significantly improved on accuracy and reaction time in the training task. Compared to the test-retest control group, trained DPs demonstrated significant improvements on whole trials in the part-whole task (similar to a recent intervention study with autistic children by Tanaka and colleagues (2010)). Unfortunately, group-level improvements were limited to the part-whole task and these improvements did not necessarily correspond with robust real-world improvements. In summary, it is possible to improve aspects of face processing in a larger sample of DPs through face training, but these improvements may be limited to the face processes trained and may be limited in their real-world implications.

Training to Improve Hearing Speech in Noise: Biological Mechanisms

We investigated training-related improvements in listening in noise and the biological mechanisms mediating these improvements. Training-related malleability was examined using a program that incorporates cognitively based listening exercises to improve speech-in-noise perception. Before and after training, auditory brainstem responses to a speech syllable were recorded in quiet and multitalker noise from adults who ranged in their speech-in-noise perceptual ability. Controls did not undergo training but were tested at intervals equivalent to the trained subjects. Trained subjects exhibited significant improvements in speech-in-noise perception that were retained 6 months later. Subcortical responses in noise demonstrated training-related enhancements in the encoding of pitch-related cues (the fundamental frequency and the second harmonic), particularly for the time-varying portion of the syllable that is most vulnerable to perceptual disruption (the formant transition region). Subjects with the largest strength of pitch encoding at pretest showed the greatest perceptual improvement. Controls exhibited neither neurophysiological nor perceptual changes. We provide the first demonstration that short-term training can improve the neural representation of cues important for speech-in-noise perception. These results implicate and delineate biological mechanisms contributing to learning success, and they provide a conceptual advance to our understanding of the kind of training experiences that can influence sensory processing in adulthood.

Hebbian-Type Stimulation During Robot-Assisted Training in Patients With Stroke

Background. Training-related improvements in motor function are associated with changes in movement representation of the primary motor cortex (M1). In healthy individuals, transcranial magnetic stimulation (TMS) of M1 delivered in a strict temporal relationship (Hebbian-type stimulation) during execution of movements enhances these effects and is superior to random stimulation. Objective. The authors tested whether training combined with Hebbian-type M1 stimulation enhances M1 reorganization in patients with stroke. Methods. Six patients with chronic stroke participated in the study. Patients executed robot-assisted wrist extension movements at 0.2 Hz frequency while subthreshold repetitive TMS was applied over M1 in a strict temporal relationship to the training movements. TMS was applied to either the affected hemisphere (contralateral M1) or the nonaffected hemisphere (ipsilateral M1) at 0.1 Hz. Intervention-related changes in motor maps and intracortical excitability were measured using TMS. Results. Training alone or combined Hebbian-type stimulation of either M1 resulted in differential effects on motor maps and intracortical inhibition. Shifts in motor maps were associated with increases in intracortical excitability. In contrast to previous results for healthy participants, the inhibitory effect of ipsilateral M1 Hebbian-type stimulation was not present, and the facilitatory effect of contralateral M1 stimulation was more subtle. Conclusions. Hebbian-type stimulation is feasible in patients poststroke and induces map reorganization and associated decreases in GABAergic inhibition. However, because TMS protocols have a different effect on motor reorganization in the injured brain and may depend on location of the lesion, protocols need to be tailored to the patient’s pathology.

Comparison of the effect of upper body-ergometry aerobic training vs treadmill training on central cardiorespiratory improvement and walking distance in patients with claudication

Supervised treadmill-walking exercise programs have been proven to be a highly effective in improving walking distance in peripheral arterial disease (PAD) patients with lifestyle-limiting claudication. Limited information is available on the contributions of central cardiorespiratory functions for improving these patients' walking capacity with exercise training. This study randomized 28 participants (21 men; age, 65.6 years; 92.7% smoking history, 36.6% with diabetes) with lifestyle-limiting PAD-related claudication to 3 hours/week of supervised exercise training for 12 weeks, using arm-ergometry (n = 10) or treadmill-walking (n = 10) vs a usual-care control group (n = 8). Cardiorespiratory function measurements were assessed before and after training at a submaximal workload and at the onset of claudication (pain-free walking distance [PFWD]) and at maximal walking distance [(MWD]). Changes in these functions from baseline were analyzed among the groups with analysis of covariance. Associations between variables were determined by Pearson's partial correlations. The mean baseline demographic, medical, and exercise variables were similar among the groups. There were similar significant differences in the submaximal double product (heart rate × systolic blood pressure) and at MWD, ventilatory threshold, ventilatory oxygen uptake (VO(2)) at onset of claudication, and VO(2) peak in response to training in both exercise groups vs the control group. Statistically significant, moderate correlations (r = 0.60-0.68) were found between changes in all cardiorespiratory variables and changes in PFWD or MWD. Improvements in cardiorespiratory function after arm-ergometry or treadmill-training were significantly associated with improvements in both PFWD and MWD, providing supporting evidence of systemic contributions to exercise training-related improvements in walking capacity seen in patients with claudication.

Influence of a Locomotor Training Approach on Walking Speed and Distance in People With Chronic Spinal Cord Injury: A Randomized Clinical Trial

Impaired walking limits function after spinal cord injury (SCI), but training-related improvements are possible even in people with chronic motor incomplete SCI. The objective of this study was to compare changes in walking speed and distance associated with 4 locomotor training approaches. This study was a single-blind, randomized clinical trial. This study was conducted in a rehabilitation research laboratory. Participants were people with minimal walking function due to chronic SCI. Participants (n=74) trained 5 days per week for 12 weeks with the following approaches: treadmill-based training with manual assistance (TM), treadmill-based training with stimulation (TS), overground training with stimulation (OG), and treadmill-based training with robotic assistance (LR). Overground walking speed and distance were the primary outcome measures. In participants who completed the training (n=64), there were overall effects for speed (effect size index [d]=0.33) and distance (d=0.35). For speed, there were no significant between-group differences; however, distance gains were greatest with OG. Effect sizes for speed and distance were largest with OG (d=0.43 and d=0.40, respectively). Effect sizes for speed were the same for TM and TS (d=0.28); there was no effect for LR. The effect size for distance was greater with TS (d=0.16) than with TM or LR, for which there was no effect. Ten participants who improved with training were retested at least 6 months after training; walking speed at this time was slower than that at the conclusion of training but remained faster than before training. It is unknown whether the training dosage and the emphasis on training speed were optimal. Robotic training that requires active participation would likely yield different results. In people with chronic motor incomplete SCI, walking speed improved with both overground training and treadmill-based training; however, walking distance improved to a greater extent with overground training.

Transfer of task-switching training in older age: The role of verbal processes.

This study investigated the influence of verbal self-instructions (VSI) on the transfer of task-switching training in older adults (56-78 years). We applied an internally cued switching paradigm in a pretest-training-posttest design. Training-related improvements were not modulated by VSI. Transfer (the pretest-posttest reduction of switch costs) was most pronounced when participants applied the VSI at posttest after practicing the switching task without VSI. The results indicate that in contrast to transfer of executive control training, transfer of (verbal) strategy training seems to be limited and that VSI is most beneficial when the task-switching abilities are already well practiced.

Cardiac Rehabilitation After Stroke—Need and Opportunity

In North America, established long-term rehabilitation programs are commonly available for individuals following a cardiac event but are largely unavailable for stroke survivors. The purpose of this study was to determine (1) the availability of cardiac rehabilitation (CR) for individuals poststroke (survey of all programs in Ontario, Canada) and (2) the effects of CR, comparing individuals with primary and secondary diagnoses of stroke versus those with cardiac diagnoses only (retrospective review of a large outpatient North American program). An Ontario-wide survey was disseminated to CR programs to determine barriers to enrollment of stroke participants. Additionally, a retrospective analysis of data from 9,173 participants in 1 CR program in Toronto, Ontario, compared 3 subgroups (n = 19 each): (1) primary diagnosis of stroke or transient ischemic attack (TIA), (2) primary cardiac diagnosis and occurrence of stroke or TIA, and (3) cardiac diagnoses only. Twenty-four of 40 (60%) programs surveyed included stroke participants, although the proportion was small (<5% of total enrollment). Barriers to enrollment included issues around primary diagnosis and degree of stroke-related disability. While those with a history of stroke or TIA had a lower baseline peak oxygen uptake, all 3 groups showed comparable postprogram improvements in peak oxygen uptake and anaerobic threshold (time effect, P < .001). There were no group-time interaction effects. Despite the common cardiovascular etiology of stroke and heart disease, individuals with stroke are not routinely included in CR in Ontario. However, individuals with stroke demonstrated similar training-related improvements in exercise capacity compared with nonstroke participants.

Effect of Training on Upper-Extremity Prosthetic Performance and Motor Learning: A Single-Case Study

Dromerick AW, Schabowsky CN, Holley RJ, Monroe B, Markotic A, Lum P. Effect of training on upper-extremity prosthetic performance and motor learning: a single-case study. Objectives To examine the impact of a new prosthesis on an experienced and highly motivated prosthetic limb user, to evaluate the effects of training and the ability of clinical measures to detect change, and to gain insight into the mechanisms by which improvement occurs. Design A single-case study. Setting An outpatient clinic. Participant A bilateral high-arm amputee (right shoulder disarticulation, left above elbow). Interventions Provision of new prosthesis and occupational therapy. Main Outcome Measures Action Research Arm Test, box and block test of manual dexterity, Jebsen-Taylor Hand Function Test, and speed and accuracy of reaching movements with and without visual guidance. Results In this experienced prosthesis user, provision of a new prosthesis led to an immediate worsening in functional limitation. With training, the subject recovered his baseline status and then exceeded it in both proximal and distal function. All study clinical measures detected change, but the change detected varied as much as 300-fold depending on the measure chosen. The clinical improvements were associated with modest improvements in the speed of reaching but not the accuracy of reaching under visual guidance. Improvements in reaching accuracy without visual guidance were seen after 10 trials, suggesting that some motor learning had occurred. Conclusions Provision of a new prosthesis can cause functional decline even in an experienced user; this decline can be reversed with training. There is wide variability in sensitivity to change among functional limitation measures. Although some training-related improvements may have been due to increased speed and accuracy of reaching without visual guidance, skill in prosthesis use also plays a role.

Abstract 3111: Contribution of Improved Cardiorespiratory Functions to Increased Pain-Free and Maximal Walking Distance in Patients with Claudication Following Arm Ergometer or Treadmill Exercise Training

Introduction: We previously reported that arm ergometer exercise training improves walking distance in patients with claudication similar to treadmill exercise training through unknown mechanisms. This is the first study to investigate the effects of 12 weeks of arm ergometer or treadmill training on cardiorespiratory functions during treadmill exercise testing in patients with claudication, as compared to a usual care control group. Hypothesis: Both arm ergometer and treadmill training will significantly improve cardiorespiratory functions, which will contribute to improvement in both pain-free walking distance (PFWD) and maximal walking distance (MWD). Methods: Participants (21m, 7f, mean age 65.6 yrs, 86 % smoke hx., 27% diabetes) with claudication were randomly assigned to supervised exercise training [arm ergometry (n=10) or treadmill (n=10) ] for 12 weeks, 3h/week, or to a usual care control group (n=8). Double product at stage 1 and at MWD, anaerobic threshold, and VO 2 at onset of claudication pain and VO 2 peak were assessed during a symptom-limited, graded treadmill exercise test. Changes in these functions from baseline were analyzed between groups via ANCOVA and associations between variables were determined by Pearson’s partial correlations. Results: Groups did not differ in baseline demographic, medical or exercise variables. There were significant differences in response of cardiorespiratory variables to training in both exercise groups compared to the control group, but no statistical differences between exercise groups. Significant moderate correlations were found between changes in all cardiorespiratory variables and changes in PFWD or MWD (Table 1 ). Conclusion: Improvements in cardiorespiratory functions following arm ergometer or treadmill training were significantly associated with changes in PFWD and MWD, supporting systemic contributions to exercise training-related improvements seen in patients with claudication. Changes from Baseline in Submaximal and Maximal Cardiorespiratory Variables and Walking Improvement

Auditory processing disorder in children with reading disabilities: effect of audiovisual training

Reading disability is associated with phonological problems which might originate in auditory processing disorders. The aim of the present study was 2-fold: first, the perceptual skills of average-reading children and children with dyslexia were compared in a categorical perception task assessing the processing of a phonemic contrast based on voice onset time (VOT). The medial olivocochlear (MOC) system, an inhibitory pathway functioning under central control, was also explored. Secondly, we investigated whether audiovisual training focusing on voicing contrast could modify VOT sensitivity and, in parallel, induce MOC system plasticity. The results showed an altered voicing sensitivity in some children with dyslexia, and that the most severely impaired children presented the most severe reading difficulties. These deficits in VOT perception were sometimes accompanied by MOC function abnormalities, in particular a reduction in or even absence of the asymmetry in favour of the right ear found in average-reading children. Audiovisual training significantly improved reading and shifted the categorical perception curve of certain children with dyslexia towards the average-reading children's pattern of voicing sensitivity. Likewise, in certain children MOC functioning showed increased asymmetry in favour of the right ear following audiovisual training. The training-related improvements in reading score were greatest in children presenting the greatest changes in MOC lateralization. Taken together, these results confirm the notion that some auditory system processing mechanisms are impaired in children with dyslexia and that audiovisual training can diminish these deficits.

Perceptual training improves syllable identification in new and experienced hearing aid users

We assessed the effects of perceptual training of syllable identification in noise on nonsense syllable test (NST) performance of new (Experiment 1) and experienced (Experiment 2) hearing aid (HA) users with sensorineural hearing loss. In Experiment 1, new HA users were randomly assigned to either immediate training (IT) or delayed training (DT) groups. IT subjects underwent 8 weeks of at-home syllable identification training and in-laboratory testing, whereas DT subjects underwent identical in-laboratory testing without training. Training produced large improvements in syllable identification in IT subjects, whereas spontaneous improvement was minimal in DT subjects. DT subjects then underwent training and showed performance improvements comparable with those of the IT group. Training-related improvement in NST scores significantly exceeded improvements due to amplification. In Experiment 2, experienced HA users received identical training and testing procedures as users in Experiment 1. The experienced users also showed significant training benefit. Training-related improvements generalized to untrained voices and were maintained on retention tests. Perceptual training appears to be a promising tool for improving speech perception in new and experienced HA users.

Effects of aerobic exercise training in community-based subjects aged 80 and older: a pilot study.

To assess the ability of sedentary, frail subjects aged 80 and older to train in a community-based exercise program and to evaluate clinical factors that predict improvements in peak oxygen consumption (VO2peak). Pretest, posttest. Charlestown Retirement Community, Catonsville, Maryland Twenty-two (11 male, 11 female; mean age +/- standard deviation = 84 +/- 4.0, range 80-92) self-referred. Six months of moderate-intensity aerobic exercise training, two to three sessions/week, 20 to 30 minutes per session. Training modes included treadmill walking and/or stationary cycling. Baseline and follow-up maximal exercise treadmill tests (ETTs) with electrocardiogram monitoring and respiratory gas analysis. Six months of aerobic exercise training resulted in significant increases (mean +/- standard deviation) in ETT duration (11.9 +/- 3.3 vs 15.9 +/- 4.3 minutes; P =.01), VO2peak (1.23 +/- 0.37 vs 1.31 +/- 0.36 L/min; P =.04), and oxygen pulse (9.3 +/- 2.8 vs 10.1 +/- 3.2; P =.03). Mean heart rate was significantly lower during submaximal ETT stages 1 through 4 (P <.05), and resting systolic blood pressure decreased (146 +/- 18 vs 133 +/- 14 mmHg; P =.01) after training. Multiple regression analysis indicated that baseline VO2peak (r = 0.75, P =.002) and the total amount of time spent in exercise training (r = 0.55, P =.008) were independent predictors of the training-related improvements in VO2peak. Subjects aged 80 and older can increase aerobic capacity and reduce systolic blood pressure in a community-based exercise program of moderate intensity. The most important predictors of change in VO2peak were baseline VO2peak and the time spent in exercise training. Subjects with a lower baseline VO2peak had the greatest improvements in VO2peak after training.

Inspiratory muscle training in the patient with neuromuscular disease.

Pulmonary complications due to respiratory muscle dysfunction are commonly a source of morbidity and mortality in patients with neuromuscular diseases. This review discusses the adverse effects of respiratory muscle weakness on pulmonary mechanics and examines the role that inspiratory muscle training may play in reversing pulmonary dysfunction in these individuals. In asymptomatic persons, it is well established that the inspiratory muscles can be trained to increase both force and endurance. In patients with neuromuscular diseases, the effects of training protocols on force and endurance are more controversial. This article reviews seven studies that have evaluated respiratory muscle training in a total of 75 patients with varied neuromuscular disorders. Training regimens included breathing through inspiratory resistive loads and isocapnic hyperpnea. Despite methodologic differences among studies, investigators have generally shown that the inspiratory muscles are similar to other skeletal muscle groups in that they can be trained for both force and endurance in these patients. The training-related improvements in inspiratory muscle performance are more pronounced in patients who are less severely affected by their disease. In those patients who have disease to the extent that they are already retaining carbon dioxide, there is little change in force or endurance with training. In these individuals, the inspiratory muscles may already be working at a level sufficiently severe to provide a training stimulus with each breath. No adverse effects of inspiratory muscle training were reported. Inspiratory muscle training can improve force and endurance in patients with neuromuscular weakness.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of Dynavision rehabilitation on behind-the-wheel driving ability and selected psychomotor abilities of persons after stroke.

Many conventional rehabilitation exercises, such as pencil-and-paper and computer tasks, may not train perceptual and motor skills as applied to a complex, multiskill activity such as driving. The present study examined the usefulness of the Dynavision apparatus for driving-related rehabilitation. The Dynavision was designed to train visual scanning, peripheral visual awareness, visual attention, and visual-motor reaction time across a broad, active visual field. Ten persons with a cerebrovascular accident participated in the study. All had failed behind-the-wheel driving assessments. Subjects participated in a 6-week Dynavision training program using exercises designed to impose various motor, perceptual, and cognitive demands. Dynavision training resulted in significantly improved behind-the-wheel driving assessments as compared to expected outcomes. Comparisons between pretests, posttests, and follow-up tests on a number of Dynavision, response, and reaction time variables showed significant improvements and maintenance effects. Dynavision performance, and, to a lesser extent, choice visual reaction and response times, were found to differentiate between persons assessed as safe and unsafe to drive, and between older and younger drivers. Subject self-reports suggested that a variety of training-related improvements had occurred in everyday functioning. Dynavision training shows some rehabilitative promise for improving driving and basic psychomotor skills. Future research on the benefits and limitations of this apparatus should use finer laboratory skill measures and more comprehensive tests of driving and daily functioning to assess more thoroughly skill improvements in persons after stroke.