Facilitating acquisition and transfer of a continuous motor task in healthy older adults and patients with Alzheimer's disease

Examining gait aid use and user safety by older people with dementia: Perspectives of informal carers to inform practice

PURPOSE

To determine gait aid use and decision-making related to usage in people with dementia, and examine factors influencing (1) gait aid use or not; and (2) falls in past year.

MATERIALS AND METHODS

A survey of informal carers of older people with dementia in the community. Closed questions on gait aid use, falls, timing and sources of gait aid acquisition, and advice received to support use were used. Chi-squared tests (Fisher's Exact) compared: (1) gait aid users vs non-users and carers' report of (i) unsteadiness in walking/turning, (ii) dementia severity, (iii) falls in past year, and (2) fallers vs non-fallers and (i) timing of gait aid commencement relative to dementia diagnosis, (ii) whether health professional advice was received regarding use, and iii) regularity of use.

RESULTS

Forty-seven completed surveys, 63.8% of care recipients used a gait aid; 56.9% had ≥2 falls in past year; 66.7% commenced use after dementia diagnosis; 25% acquired their aids from non-health professionals; and 37% did not receive advice regarding use. Gait aid users and non-users differed on carer ratings of unsteadiness in walking/turning (p = 0.02).

CONCLUSION

Carers reported important aspects regarding gait aid acquisition, safe gait aid use and benefits which warrant further investigation.IMPLICATIONS FOR REHABILITATIONIn our small sample, use of gait aids by people with dementia was related to the level of unsteadiness in walking and/or turning, and not associated with falling in the past year.People with dementia do not routinely receive professional advice about how to use gait aids, highlighting the potential value of maximizing health professional involvement in gait aid prescription and training.Deterioration in the ability of gait aid use after the diagnosis of dementia indicates a need for re-assessment or re-training of gait aid use over time.Clinical guidelines to facilitate decision-making regarding under what conditions gait aids are beneficial, what duration and aspects require instruction to ensure effective use by people with dementia are needed.

Does Cognitive Impairment Impact Motor Learning? A Scoping Review of Elderly Individuals With Alzheimer's Disease and Mild Cognitive Impairment

Individuals with cognitive impairment may have motor learning deficits due to the high engagement of cognitive mechanisms during motor skill acquisition. We conducted a scoping review to address the quality of current research on the relationship between cognitive impairments (i.e., deficits in attention, memory, planning and executive functions) and motor learning among older adults with Alzheimer's Disease or Mild Cognitive Impairment. After screening thousands of articles, we selected 15 studies describing cognitive assessment tools, experimental designs, and the severity of cognitive impairment. Although seven studies reported that cognitive impairment impaired motor learning, most studies included a high risk of bias. We identified multiple assessment tools across these studies that make comparisons among findings difficult. Future research in this area should focus on the influence of increased practice days during motor learning acquisition and incorporate both retention and transfer tests. Cognitive assessments should target the specific cognitive skills or deficits most closely related to the motor learning process.

The Potential for Effect of a Six-Week Training Program for Gait Aid Use in Older People with Dementia with Unsteadiness of Gait: A Pilot Study

This study examined the potential for effect of a six-week gait aid training program for people with dementia on spatiotemporal gait outcomes, perception of use, and falls with gait aid use. The program utilised four 30-min physiotherapy home visits, scheduled at weeks 1/2/3/6, and was enhanced by carer-supervised practice. Falls and the physiotherapist's clinical judgement of participants achieving safe gait aid use during and after the program were described. Perception ratings at each visit were measured using Likert scales which, along with the spatiotemporal outcomes using the gait aid (Time-Up-and-Go-Test, 4-m-walk-test, Figure-of-8-Walk-Test with/without a cognitive task) at weeks 1 and 6, and at weeks 6 and 12 (6-week post-program), were examined with ordinal logistic regression analyses. Twenty-four community-dwelling older people with dementia and their carers participated. Twenty-one (87.5%) older people achieved safe gait aid use. Twenty falls occurred, and only one faller was using their gait aid when they fell. Walking speed, step length, and cadence significantly improved when walking with the gait aid at week 6 compared with week 1. No significant improvements in spatiotemporal outcomes were retained at week 12. Physiotherapists were more likely to agree that gait aid use had improved walking safety among older people with dementia with subsequent training visits. Larger studies of the gait aid training program are needed for this clinical group.

A Biopsychosocial Model of Mealtime Management in Persons with Dementia, an Asset-Based Approach to Patient-Centered Care

Considering the rapid increase in the population over the age of 65, there is increasing need to consider models of care for persons with dementia (PWD). One common deficit associated with dementia progression is difficulty with successful participation in mealtimes. Difficulty participating in mealtimes in PWD is not the result of one factor, but rather a confluence of biological, psychological, and social characteristics common in dementia. Factors leading to mealtime difficulties for PWD may include changes in cognitive status, altered sensorimotor functioning, and increased reliance on caregiver support. The complex nature of biological, psychological, and social factors leading to mealtime difficulty highlights the need for a pragmatic model that caregivers can utilize to successfully support PWD during mealtimes. Existing models of dementia and mealtime management were reviewed and collated to create a model of mealtime management that considers this complex interplay. The Biopsychosocial Model of Mealtime Management builds on past research around patient-centered care and introduces an asset-based approach to capitalize on a PWD's retained capabilities as opposed to compensating for disabilities associated with dementia. We hope this model will provide a framework for caregivers to understand what factors impact mealtime participation in PWD and provide appropriate means on intervention.

Effects of Motor Learning Interventions on Walking Performance and Physical Function in Older Adults With Cognitive Impairment and Dementia: A Systematic Review and Meta-Analysis

Older adults with cognitive impairment have deficits in executive systems that affect their gait automaticity. The aim of the meta-analysis and systematic review was to examine the effects of interventions focus on only motor learning principles on gait performance and physical functions (e.g., dynamic balance). After inspections of 879 articles, 11 relevant studies were selected for systematic review and meta-analysis. The PEDro scale and Modified Downs and Black checklist were used to assess the quality of studies, and a random-effect model was used at a 95% confidence interval for calculating pooled effect sizes. The results of this systematic review and meta-analysis showed that motor learning interventions increased gait speed, cadence, stride length, and reduced gait cognitive cost but did not affect gait variability and physical function. In conclusion, practitioners should pay attention more to the potential benefits of motor learning interventions in rehabilitating older adults with cognitive impairment.

A framework for rehabilitation for older adults living with dementia

Introduction & Background

The aging of the population assures increased prevalence of Individuals Living with Dementia (ILwD) and there will be an increased representation of this cohort requiring physical rehabilitation. If physical therapists (PTs) manage these patients as they do their age-matched, cognitively-intact peers, they will likely be unsuccessful. ILwD have unique needs related to interpersonal and pragmatic components of rehabilitation. Therapeutic nihilism (doubting the benefit of therapy) is well-documented in PTs, either because of existing biases about dementia or previous challenges in working with ILwD. Physical rehabilitation eligibility and placement decisions are often made by PTs without special training in dementia, based upon brief exposure to patients in environments not well-designed for their best functioning. This can lead to underestimation of rehabilitation potential and denial of future PT services. PTs who work with ILwD desire more practical knowledge and targeted skills. Those with more education and training have a more positive attitude and outlook related to ILwD.

Purpose

The purpose of this paper is to introduce a framework for rehabilitation with ILwD equipped with pragmatic ideas to facilitate therapeutic success. The four primary components of the model are: (1) Establish a personal RELATIONSHIP, (2) Use intentional verbal and nonverbal COMMUNICATION, (3) Understand and optimize MOTOR LEARNING capabilities, and (4) Create a safe, purposeful ENVIRONMENT. Specific strategies to help PTs optimize each component are provided with supporting evidence. The model is intended to be dynamic, encouraging PTs to capitalize on the most accessible strategies within their control for a given patient and setting.

Implications

This framework provides a practical resource for working with ILwD with immediate implications for facilitating therapeutic success. The model is displayed in a schematic that reminds the reader of ideas at a glance within the context of each of the components. If an appreciation for this content was among core competencies required among PTs working with ILwD, perhaps there would be significantly fewer patients written off as “uncooperative” or “unable to participate” in PT.

A survey of nurses, physiotherapists and occupational therapists in mobility care and gait aid use for hospital patients with dementia

This study described mobility care practice of nurses, physiotherapists and occupational therapists and gait aid use for hospital patients with dementia. Two surveys, tailored to staff mobility care roles were distributed in Australian hospitals. Physiotherapists and occupational therapists were asked additional questions regarding assessments and factors for prescribing gait aids to patients with dementia. Descriptive statistics for closed-ended and summative content analyses for open-ended questions were undertaken. Nurses (n=56), physiotherapists (n=11) and occupational therapists (n=23) used various practices to ensure ambulation safety for patients with dementia. Nurses and occupational therapists commonly referred patients with dementia to physiotherapists for mobility and gait aid assessments. Therapists predominantly considered the severity of dementia, the person's learning ability and mobility history in deciding about gait aid use. Exploring ways to strengthen nursing and health professional education, and inter-professional practice for safe mobility in patients with dementia, with and without gait aids, could be helpful.

Normal Aging Affects the Short-Term Temporal Stability of Implicit, But Not Explicit, Motor Learning following Visuomotor Adaptation

Normal aging is associated with a decline in memory and motor learning ability. However, the exact form of these impairments (e.g., the short-term temporal stability and affected learning mechanisms) is largely unknown. Here, we used a sensorimotor adaptation task to examine changes in the temporal stability of two forms of learning (explicit and implicit) because of normal aging. Healthy young subjects (age range, 19–28 years; 20 individuals) and older human subjects (age range, 63–85 years; 19 individuals) made reaching movements in response to altered visual feedback. On each trial, subjects turned a rotation dial to select an explicit aiming direction. Once selected, the display was removed and subjects moved the cursor from the start position to the target. After initial training with the rotational feedback perturbation, subjects completed a series of probe trials at different delay periods to systematically assess the short-term retention of learning. For both groups, the explicit aiming showed no significant decrease over 1.5 min. However, this was not the case for implicit learning; the decay pattern was markedly different between groups. Older subjects showed a linear decrease of the implicit component of adaptation over time, while young subjects showed an exponential decay over the same period (time constant, 25.61 s). Although older subjects adapted at a similar rate, these results suggest natural aging selectively impacts the short-term (seconds to minutes) temporal stability of implicit motor learning mechanisms. This understanding may provide a means to dissociate natural aging memory impairments from deficits caused by brain disorders that progress with aging.

Effectiveness of gait aid prescription for improving spatiotemporal gait parameters and associated outcomes in community-dwelling older people: a systematic review

PURPOSE

To integrate the evidence of gait aid prescription for improving spatiotemporal gait parameters, balance, safety, adherence to gait aid use, and reducing falls in community-dwelling older people.

METHODS

Seven health databases were searched to June 2021. Experimental studies investigating gait aid prescription (provision and instruction for use) for older people, reporting gait parameters, balance, falls, and safety of or adherence to gait aid use was included. Mean differences with 95% confidence intervals of gait and balance outcomes in participants at the program's last follow-up were analyzed. The safety of and adherence to gait aid use were described.

RESULTS

Eight studies were included (N = 555 older people). No meta-analyses could be performed. Five studies used a single gait aid instruction session. Gait aid prescription had inconsistent effects on gait velocity, and no reported benefits in reducing gait variability in older people with mobility problems or fall risks, including Parkinson's or Alzheimer's disease. No study investigated gait aid prescription on falls and balance performance. Effects on safety and adherence to gait aid use were unclear.

CONCLUSION

Research is needed to investigate the benefits of extensive gait aid training in older people with mobility problems, including those with dementia or high falls risk.IMPLICATIONS FOR REHABILITATIONThere is little evidence currently addressing the benefits of gait aid prescription on gait and associated outcomes in older people with mobility problems or fall risks.Gait aid prescription yielded inconsistent effects on increasing gait velocity and did not appear to reduce gait variability in older people with mobility problems or fall risks, nor in those with Parkinson's disease or Alzheimer's disease.Clinicians may consider using a more extensive gait aid training approach to optimize learning of safe gait patterns and gait aid use, which may produce better outcomes.

A Phonomotor Approach to Apraxia of Speech Treatment

Purpose This study continued Phase I investigation of a modified Phonomotor Treatment (PMT) Program on motor planning in two individuals with apraxia of speech (AOS) and aphasia and, with support from prior work, refined Phase I methodology for treatment intensity and duration, a measure of communicative participation, and the use of effect size benchmarks specific to AOS. Method A single-case experimental design with multiple baselines across behaviors and participants was used to examine acquisition, generalization, and maintenance of treatment effects 8-10 weeks posttreatment. Treatment was distributed 3 days a week, and duration of treatment was specific to each participant (criterion based). Experimental stimuli consisted of target sounds or clusters embedded nonwords and real words, specific to each participants' deficit. Results Findings show improved repetition accuracy for targets in trained nonwords, generalization to targets in untrained nonwords and real words, and maintenance of treatment effects at 10 weeks posttreatment for one participant and more variable outcomes for the other participant. Conclusions Results indicate that a modified version of PMT can promote generalization and maintenance of treatment gains for trained speech targets via a multimodal approach emphasizing repeated exposure and practice. While these results are promising, the frequent co-occurrence of AOS and aphasia warrants a treatment that addresses both motor planning and linguistic deficits. Thus, the application of traditional PMT with participant-specific modifications for AOS embedded into the treatment program may be a more effective approach. Future work will continue to examine and maximize improvements in motor planning, while also treating anomia in aphasia.

What nursing home environment can maximise eating independence among residents with cognitive impairment? Findings from a secondary analysis

To explore the influence of the Nursing Home (NH) environment on eating independence while taking into account individual and nursing care factors, was the aim of the study. A secondary analysis was performed based on data collected in a multicentre prospective observational study involving 13 NHs. Residents aged >65 were included (n = 1,027). Dependence in eating was measured using the Edinburgh Feeding Evaluation in Dementia scale (EdFED, range 0-20). In addition to individual and nursing care variables, the NHs environments were assessed with the Therapeutic Environment Screening Survey for Nursing Homes (TESS-NH, range 0-149). The mean EdFED score was 2.48 (95% Confidence Interval [CI]=2.22-2.73) and the TESS-NH score was 122.19 (95% CI=115.89-128.49). A linear regression analysis explained 30.8% of the total variance in eating dependence. Alongside individual and nursing care factors, in poor NH unit environments, residents with severe cognitive impairment showed increased eating dependence; in contrast, in better environments, similar residents showed maximal eating performance.

Procedural Learning Improves Cognition in Multiple Sclerosis

Background:

Multiple sclerosis (MS) is considered a neurodegenerative disease and an inflammatory demyelinating neuropathology in young population. Procedural memory has been poorly investigated in MS.

Objective:

We assessed whether the MS group was able to develop a motor-cognitive skill, using a procedural task (PLSC) developed in our laboratory, applying a manual and serial reaction time (RT) paradigm to semantic categorization.

Methods:

We evaluated 26 MS patients and 26 socio-demographic matched control participants using the PLSC task.

Results:

Using non-parametric statistical analyses, we observed a significant improvement of semantic categorization RTs with practice (p = 0.002), even with new verbal material to categorize in MS patients (p = 0.006), despite their motor and executive moderate deficits. This same profile of semantic procedural learning in MS was observed in previous studies carried out with Alzheimer’s and Parkinson’s diseases. Moreover, the visual-motor RTs remained stable or slightly improved over the five blocks in both groups, as well as in the AD groups of previous studies. The MS group showed longer visual-motor reaction times than those of the control group (p < 0.042), except in motor initiation aspect (p = 0.064). Both groups showed no significant differences for any type of error. Additionally, disability level and cognitive performances were not associated with the ratio of semantic procedural learning.

Conclusion:

The present results support the notion that MS patients may be capable of acquiring semantic skill, despite their motor disabilities and executive troubles. This work also addresses the possibilities to improve motor-cognitive skill RTs in neurodegenerative diseases.

Variable training but not sleep improves consolidation of motor adaptation

How motor memory consolidates still remains elusive. Consolidation of motor skills has been shown to depend on periods of sleep. Conversely, motor adaptation during tasks not dependent on the hippocampus may not depend on sleep. Some research suggests that the training schedule affects the sleep dependency of motor adaptation tasks. Here, we investigated whether sleep differentially affects memory consolidation that depends on the training schedule. Healthy men were trained with their dominant, right hand on a force-field adaptation task and re-tested after an 11-h consolidation period involving overnight sleep (Sleep) or daytime wakefulness (Wake). Retesting included a transfer test of the non-dominant hand. Half of the subjects in each group adapted to different force-field magnitudes during training with low inter-trial force variability (Sleep-Blocked; Wake-Blocked), and the other half were trained with a high-variability schedule (Sleep-Random; Wake-Random). EEG was recorded during task execution and overnight polysomnography. Consolidation was comparable between Wake and Sleep groups, although performance changes over sleep correlated with sleep spindles nesting in slow-wave upstates. Higher training variability improved retest performance, including transfer learning, and these improvements correlated with higher alpha power in contralateral parietal areas. These enhanced consolidation effects might be fostered by feedback rather than feedforward mechanisms.

Motor-cognitive effects of a computerized game-based training method in people with dementia: a randomized controlled trial

OBJECTIVES

To examine the effects of a computerized, game-based training on motor-cognitive performances, the transfer of training effects on untrained tasks, and the sustainability of training gains in people with dementia.

METHOD

Ninety-nine individuals with a mean age of 82.9 (5.8) and dementia participated in a 10-week randomized controlled trial with three-month follow-up. The intervention group (IG) received a motor-cognitive training on (Physiomat®) including concurrent dual-tasks of balance control with cognitive demands (Physiomat®-Trail Making Tasks (PTMTs)). The control group (CG) performed non-specific, low-intensity exercises. Duration and accuracy at different complexity levels of trained and untrained PTMTs and the number of successfully performed tasks (PTMT score) were assessed.

RESULTS

Physiomat® training significantly improved the duration and accuracy at almost all complexity levels of trained (P ≤ 0.001-0.047, η_p² = 0.065-0.589) and untrained PTMTs (P < 0.001-0.005, η_p² = 0.073-0.459). Significant effects were also found for the PTMT score of trained (P < 0.001, η_p² = 0.211) and untrained PTMTs (P < 0.001, η_p² = 0.184). Training gains were partly sustained at follow-up.

CONCLUSION

Physiomat® is feasible and has the potential to sustainably improve motor-cognitive performances in people with dementia.

People with Dementia Can Learn Compensatory Movement Maneuvers for the Sit-to-Stand Task: A Randomized Controlled Trial

BACKGROUND

A complex motor skill highly relevant to mobility in everyday life (e.g., sit-to-stand [STS] transfer) has not yet been addressed in studies on motor learning in people with dementia (PwD).

OBJECTIVE

To determine whether a dementia-specific motor learning exercise program enables PwD to learn compensatory STS maneuvers commonly taught in geriatric rehabilitation therapy to enhance patients' STS ability.

METHODS

Ninety-seven patients with mild-to-moderate dementia (Mini-Mental State Examination: 21.9±2.9 points) participated in a double-blinded, randomized, placebo-controlled trial with 10-week intervention and 3-month follow-up period. The intervention group (IG, n = 51) underwent a motor learning exercise program on compensatory STS maneuvers specifically designed for PwD. The control group (CG, n = 46) performed a low-intensity motor placebo activity. Primary outcomes were scores of the Assessment of Compensatory Sit-to-stand Maneuvers in People with Dementia (ACSID), which covers the number of recalled and initiated, and of effectively performed compensatory STS maneuvers. Secondary outcomes included temporal and kinematic STS characteristics measured by a body-fixed motion sensor (BFS, DynaPort® Hybrid).

RESULTS

The IG significantly improved in all ACSID scores compared to the CG (p < 0.001). Secondary analysis confirmed learning effects for all BFS-based outcomes (p < 0.001-0.006). Learning gains were sustained during follow-up for most outcomes.

CONCLUSION

People with mild-to-moderate dementia can learn and retain compensatory STS maneuvers in response to a dementia-specific motor learning exercise program. This is the first study that demonstrated preserved motor learning abilities in PwD by using a motor skill highly relevant to everyday life.

Effects of a High-Intensity Functional Exercise Program on Dependence in Activities of Daily Living and Balance in Older Adults with Dementia

OBJECTIVES

To investigate the effects of a high-intensity functional exercise program on independence in activities of daily living (ADLs) and balance in older people with dementia and whether exercise effects differed between dementia types.

DESIGN

Cluster-randomized controlled trial: Umeå Dementia and Exercise (UMDEX) study.

SETTING

Residential care facilities, Umeå, Sweden.

PARTICIPANTS

Individuals aged 65 and older with a dementia diagnosis, a Mini-Mental State Examination score of 10 or greater, and dependence in ADLs (N=186).

INTERVENTION

Ninety-three participants each were allocated to the high-intensity functional exercise program, comprising lower limb strength and balance exercises, and 93 to a seated control activity.

MEASUREMENTS

Blinded assessors measured ADL independence using the Functional Independence Measure (FIM) and Barthel Index (BI) and balance using the Berg Balance Scale (BBS) at baseline and 4 (directly after intervention completion) and 7 months.

RESULTS

Linear mixed models showed no between-group effect on ADL independence at 4 (FIM=1.3, 95% confidence interval (CI)=-1.6-4.3; BI=0.6, 95% CI=-0.2-1.4) or 7 (FIM=0.8, 95% CI=-2.2-3.8; BI=0.6, 95% CI=-0.3-1.4) months. A significant between-group effect on balance favoring exercise was observed at 4 months (BBS=4.2, 95% CI=1.8-6.6). In interaction analyses, exercise effects differed significantly between dementia types. Positive between-group exercise effects were found in participants with non-Alzheimer's dementia according to the FIM at 7 months and BI and BBS at 4 and 7 months.

CONCLUSION

In older people with mild to moderate dementia living in residential care facilities, a 4-month high-intensity functional exercise program appears to slow decline in ADL independence and improve balance, albeit only in participants with non-Alzheimer's dementia.

Optimizing Eating Performance for Long-Term Care Residents With Dementia: Testing the Impact of Function-Focused Care for Cognitively Impaired

OBJECTIVES

The objective of this study was to evaluate the impact of a well-developed theory-based function-focused care for cognitively impaired (FFC-CI) intervention on eating performance among long-term care (LTC) residents with moderate-to-severe cognitive impairment.

DESIGN

A secondary analysis of longitudinal data from 2 cluster-randomized controlled trials that originally tested the impact of FFC-CI on all function and physical activities.

PARTICIPANTS AND SETTING

Participants were 199 residents with moderate-to-severe cognitive impairment from 4 nursing homes and 4 assisted living facilities.

MEASUREMENTS

Data at baseline, and 3 and 6 months were used. Resident outcome data used in this analysis included eating performance conceptualized using the single self-care "feeding" item in the Barthel Index, cognitive function by Mini-Mental State Examination, sitting balance conceptualized using the single "chair sit-sitting balance" item in the Tinetti Gait and Balance scale, physical capability by Physical Capability Scale, depression by Cornell Scale for Depression in Dementia, and agitation by Cohen-Mansfield Agitation Inventory (short form).

RESULTS

At baseline, almost one-third (32.2%) of the 199 residents needed help with eating. There was no significant change with regard to eating performance over time in both groups, and no significant treatment by time difference between groups in eating performance (P = .195).

CONCLUSION

Current findings support a need to revise the FFC-CI to better address eating performance. Future work may benefit from a stronger focus on eating performance rather than the more commonly addressed functional tasks, such as bathing, dressing, and ambulation. In addition, the inclusion of a more heterogeneous group of LTC residents with regard to eating performance is needed to test the impact of the revised approach on eating performance.

Tasks matter: a cross-sectional study of the relationship of cognition and dual-task performance in older adults

BACKGROUND

Dual-task (DT) performance, the ability to divide one's attention between motor and secondary tasks, is required in daily life. Adults with cognitive impairment (CI) experience more difficulty with DTs than healthy older adults, but it is unclear how the degree of CI relates to DT performance, particularly with tasks of varying levels of difficulty.

PURPOSE

The purposes of this cross-sectional study were to (1) explore the relationship between cognitive level and DT performance and (2) determine how the difficulty of the combined tasks impacts this relationship.

METHODS

Twenty-three older adults with Mini-Mental State Examination (MMSE) scores ranging from 7 to 30 performed 2 single tasks (ST): the Timed Up and Go (TUG) and a 6-m walk for which self-selected walking speed (SSWS) was calculated. Each ST was repeated under 2 DT conditions: counting forward by 1's (TUG1 and SSWS1) and counting backward by 3's (TUG3 and SSWS3). Dual-task cost (DTC) was calculated for each DT as follows: [(difference between DT and ST motor performance)/ST motor performance] × 100. Spearman rank correlation coefficients were used to determine the relationship between DTC and the MMSE. The Friedman 2-way ANOVA on ranks was used to compare the magnitude of DTC among the 4 DTs.

RESULTS

Significant correlations between the MMSE and DTC were found for SSWS3, TUG1, and TUG3 (r = 0.43-0.57). SSWS1 had a weaker and nonsignificant correlation between MMSE and DTC (r = 0.36). The TUG3 was the most difficult DT, while the SSWS1 was the easiest DT. All participants, regardless of MMSE score, were able to engage in all DTs.

DISCUSSION AND CONCLUSIONS

A linear relationship exists between cognition and DTC in older adults with varying cognitive levels. The strength of this relationship is greater for more challenging tasks. We also suggest that patients with CI may be able to engage in more challenging tasks than might be assumed. The impact of task difficulty has implications in the design of future studies of DT training for individuals both with and without CI.

Blocked and alternating variable practice and unintended spatial variations in continuous aiming movements

The main goal of the study was to test a prediction of schema theory: a wider range of variable practice would result in better transfer performance compared to a narrower range of variable practice in less-studied, continuous aiming movements. Constant and variable amplitude continuous aiming movements were investigated in the preferred hand of participants of college age (N = 32; 8 men, 24 women). Participants made continuous rapid reversal movements with a lever in the horizontal plane. Groups attempted to reach a short (20 degrees) target and a long target (either 45 degrees or 70 degrees) in separate constant-practice conditions, but alternated between the two targets in a variable practice condition. On the transfer test, participants alternated between unpracticed 10 degrees and 80 degrees targets. Four blocks of practice trials were provided in each condition, with 20 movements made in each. Movements were more accurate and consistent during constant practice compared to variable practice, with the 20 degrees-70 degrees group having greater spatial errors compared to the 20 degrees-45 degrees group. Both groups performed equally well on the novel transfer test suggesting that adequate practice variability had been provided during acquisition.

Impaired acquisition of a mirror-reading skill in Alzheimer's disease

Several studies using the mirror-reading paradigm have shown that procedural learning and repetition priming may be preserved in the early stages of Alzheimer's disease (AD) (e.g., Deweer et al., 1994). According to the classical interpretation, improved reading time for repeated words is sustained by a repetition priming effect, while procedural learning is demonstrated when this improvement is also observed for new words. Following Masson (1986), the hypothesis tested in the present study was that improved reading of new words could also be due to a repetition priming effect rather than to the acquisition of a mirror-reading skill. Indeed, because the same letters are presented throughout the task, a repetition priming effect for the letters could suffice to explain the improvement in performance. To test this hypothesis, we administered to 30 healthy young and elderly subjects and to 30 AD patients a new mirror-reading task in two phases: an acquisition phase comprising pseudo-words constructed with one part of the alphabet, and a test phase in which both pseudo-words constructed with the same part of the alphabet and pseudo-words constructed with another part of the alphabet were presented. If the new pseudo-words composed with repeated letters were read faster, it would reflect a repetition priming effect; if pseudo-words composed of 'new' letters were read faster, it would reflect a procedural learning effect. The results show comparable repetition priming effects in AD patients and in healthy elderly subjects, whereas only healthy subjects showed a procedural learning effect. These results suggest, contrary to previous studies, that the learning of a new perceptual skill may not always be preserved in AD.

Alzheimer's disease and implicit memory

Specific neuropsychiatric disorders, such as Alzheimer's disease (AD) affect some forms of memory while leaving others relatively intact. In this review, we investigate particularities of the relationship between explicit and implicit memories in AD. It was found that implicit memory is preserved in AD, irrespective of the task used; in other words, there was not interference from explicit memory. In addition, it was verified that is possible through implicit memory compensatory strategies such as, activities of daily living (ADL) to compensate for the explicit memory deficits. In this sense, cognitive rehabilitation (CR) demonstrates reasonable results in the process of compensation of explicit memory deficits. Concluding, the decline in explicit memory suggests that both systems are functionally independent even if the other is compromised. We expect that when explicit memory system is not involved in competition with the implicit system, the final effect of learning is better, because all of the implicit memory capacity is engaged in learning and not in competition with the explicit system.

Motor-skill learning in Alzheimer's disease: a review with an eye to the clinical practice

Since elderly people suffering from dementia want to go on living independently for as long as possible, they need to be able to maintain familiar and learn new practical skills. Although explicit or declarative learning methods are mostly used to train new skills, it is hypothesized that implicit or procedural techniques may be more effective in this population. The present review discusses 23 experimental studies on implicit motor-skill learning in patients with Alzheimer's disease (AD). All studies found intact implicit motor-learning capacities. Subsequently, it is elaborated how these intact learning abilities can be exploited in the patients' rehabilitation with respect to the variables 'practice' and 'feedback.' Recommendations for future research are provided, and it is concluded that if training programs are adjusted to specific needs and abilities, older people with AD are well able to (re)learn practical motor skills, which may enhance their autonomy.

Preserved implicit memory in dementia: a potential model for care

A growing body of evidence supports the presence of a preserved implicit memory (PIM) system for persons with Alzheimer's disease (AD). This article describes a new approach to dementia care, the PIM model, which translates evidence from implicit memory research into a practice model of dementia care. The PIM model predicts that function can be sustained longer for persons with AD through interventions and environments that activate an individual's PIM. Activation of PIM can occur with perceptual priming of familiar objects and reinforcement of learned motor skill memories within tasks. This practice model provides a new framework for planning and implementing dementia care that may preserve function for persons with Alzheimer's dementia.

Cholinesterase inhibitors affect brain potentials in amnestic mild cognitive impairment

Amnestic mild cognitive impairment (MCI) is an isolated episodic memory disorder that has a high likelihood of progressing to Alzheimer's disease. Auditory sensory cortical responses (P50, N100) have been shown to be increased in amplitude in MCI compared to older controls. We tested whether (1) cortical potentials to other sensory modalities (somatosensory and visual) were also affected in MCI and (2) cholinesterase inhibitors (ChEIs), one of the therapies used in this disorder, modulated sensory cortical potentials in MCI. Somatosensory cortical potentials to median nerve stimulation and visual cortical potentials to reversing checkerboard stimulation were recorded from 15 older controls and 15 amnestic MCI subjects (single domain). Results were analyzed as a function of diagnosis (Control, MCI) and ChEIs treatment (Treated MCI, Untreated MCI). Somatosensory and visual potentials did not differ significantly in amplitude in MCI subjects compared to controls. When ChEIs use was considered, somatosensory potentials (N20, P50) but not visual potentials (N70, P100, N150) were of larger amplitude in untreated MCI subjects compared to treated MCI subjects. Three individual MCI subjects showed increased N20 amplitude while off ChEIs compared to while on ChEIs. An enhancement of N20 somatosensory cortical activity occurs in amnestic single-domain MCI and is sensitive to modulation by ChEIs.

Practice effects on motor control in healthy seniors and patients with mild cognitive impairment and Alzheimer's disease

This research was designed to test the hypothesis that motor practice can enhance the capabilities of motor control in healthy controls (NC) and patients with a diagnosis of probable Alzheimer's disease (AD) and mild cognitive impairment (MCI), and consequently results in better motor performance. Approximately half of the subjects in the NC (n = 31), AD (n = 28), and MCI (n = 29) either received or did not receive practice on a task of fast and accurate arm movement with a digitizer. Changes in movement time (MT), movement smoothness (jerk), and percentage of primary submovement (PPS) were recorded and compared among the three groups across six blocks of trials (baseline and five training sessions). For all subjects, practice improved motor functions as reflected by faster and smoother motor execution, as well as a greater proportion of programming control. Compared to unaffected matched controls, AD and MCI subjects exhibited a greater reduction in movement jerk due to practice. Movement time and PPS data revealed that motor practice appeared to reduce the use of "on-line" correction adopted by the AD or MCI patients while performing the aiming movements. Evidently, their arm movements were quicker, smoother, and temporally more consistent than their untrained peers. The findings of this study shed light on how MCI and AD may affect motor control mechanisms, and suggest possible therapeutic interventions aimed at improving motor functioning in these impaired individuals.

Brain plasticity and functional losses in the aged: scientific bases for a novel intervention

Aging is associated with progressive losses in function across multiple systems, including sensation, cognition, memory, motor control, and affect. The traditional view has been that functional decline in aging is unavoidable because it is a direct consequence of brain machinery wearing down over time. In recent years, an alternative perspective has emerged, which elaborates on this traditional view of age-related functional decline. This new viewpoint--based upon decades of research in neuroscience, experimental psychology, and other related fields--argues that as people age, brain plasticity processes with negative consequences begin to dominate brain functioning. Four core factors--reduced schedules of brain activity, noisy processing, weakened neuromodulatory control, and negative learning--interact to create a self-reinforcing downward spiral of degraded brain function in older adults. This downward spiral might begin from reduced brain activity due to behavioral change, from a loss in brain function driven by aging brain machinery, or more likely from both. In aggregate, these interrelated factors promote plastic changes in the brain that result in age-related functional decline. This new viewpoint on the root causes of functional decline immediately suggests a remedial approach. Studies of adult brain plasticity have shown that substantial improvement in function and/or recovery from losses in sensation, cognition, memory, motor control, and affect should be possible, using appropriately designed behavioral training paradigms. Driving brain plasticity with positive outcomes requires engaging older adults in demanding sensory, cognitive, and motor activities on an intensive basis, in a behavioral context designed to re-engage and strengthen the neuromodulatory systems that control learning in adults, with the goal of increasing the fidelity, reliability, and power of cortical representations. Such a training program would serve a substantial unmet need in aging adults. Current treatments directed at age-related functional losses are limited in important ways. Pharmacological therapies can target only a limited number of the many changes believed to underlie functional decline. Behavioral approaches focus on teaching specific strategies to aid higher order cognitive functions, and do not usually aspire to fundamentally change brain function. A brain-plasticity-based training program would potentially be applicable to all aging adults with the promise of improving their operational capabilities. We have constructed such a brain-plasticity-based training program and conducted an initial randomized controlled pilot study to evaluate the feasibility of its use by older adults. A main objective of this initial study was to estimate the effect size on standardized neuropsychological measures of memory. We found that older adults could learn the training program quickly, and could use it entirely unsupervised for the majority of the time required. Pre- and posttesting documented a significant improvement in memory within the training group (effect size 0.41, p<0.0005), with no significant within-group changes in a time-matched computer using active control group, or in a no-contact control group. Thus, a brain-plasticity-based intervention targeting normal age-related cognitive decline may potentially offer benefit to a broad population of older adults.