Memory rehabilitation for older adults: preserving independent living / Rehabilitación de la memoria para adultos mayores: preservación de la autonomía de vida

Abstract

Episodic memory problems are the hallmark of cognitive ageing in normal elderly people. Learning of new material is worse in pathological cognitive ageing, such as dementia and its preliminary states (mild cognitive impairment). Because episodic learning is crucial to preserve independent living in the elderly, rehabilitation programmes for everyday memory problems are welcomed. The scope of scientific interest has switched from treatment to prevention. We claim that lifestyle interventions are the most direct way to preserve cognition. We summarize evidence for changes in nutrition and exercise. In addition, psychological interventions for elderly people with normal or pathological cognitive ageing are available. Recent meta-analyses found lacking evidence of transfer to everyday life and long-term effects. We critically assess these meta-analyses. We propose theoretically derived experimental interventions relying on spared learning mechanisms. As an example we report visual-imagery training showing positive effects in a randomized control trial, using individual memory diaries on memory improvement.     

Quality of Life in the European Union and the United States of America: Evidence from Comprehensive Indices

The main question of this article is about the quality of life in the European Union and the United States measured by different comprehensive indicators (HDI, WBI, WISP, OLS, PWI, ABS, HLE). On the world scale moderately different levels of quality of life characterize the European Area and the US. In objective terms, the US is more at the top level regarding economy and science, whereas Europe is more at the top level regarding social concerns in a broad sense. In subjective terms, which means to rely on the usual subjective measures, the average of US population seems to be slightly better off than the average of the EU population. That said, the differences inside the EU are often more significant than those between the EU and the US. Many EU countries in Northern and Western Europe show higher satisfaction levels than the US, and Eastern Europe is especially low in respect to the satisfaction of its population. It is rather obvious that the choice of criteria and values influences the results of the comparisons of nations and supranational unions to a considerable degree.     

Perceptual-Motor Contributions to Static and Dynamic Balance Control in Children

The authors addressed balance control in children from the perspective of skill development and examined the relationship between specific perceptual and motor skills and static and dynamic balance performance. Fifty 11- to 13-year-old children performed a series of 1-legged balance tasks while standing on a force platform. Postural control was reflected in the maximum displacement of the center of mass in anterior-posterior and mediolateral directions. Simple visual, discrimination, and choice reaction times; sustained attention; visuomotor coordination; kinesthesis; and depth perception were also assessed in a series of perceptual and motor tests. The correlation analysis revealed that balancing under static conditions was strongly associated with the ability to perceive and process visual information, which is important for feedback-based control of balance. On the other hand, when greater task demands were imposed on the system under dynamic balancing conditions, the ability to respond to the destabilizing hip abductions-adductions in order to maintain equilibrium was associated with motor response speed, suggesting the use of a descending, feedforward control strategy. Therefore, like adults, 11- to 13-year-old children have the ability to select varying balance strategies (feedback, feedforward, or both), depending on the constraints of a particular task.     

Development of Postural Adjustment During Gait Initiation: Kinematic and EMG Analysis

The authors studied the development of postural adjustments associated with the initiation of gait in children by using kinematic and electromyographic (EMG) analysis. Participants (N = 28) included infants with 1-4 and 9-17 months of walking experience, children 4-5 years of age, and adults. Anticipatory postural adjustments (APA) were present in the youngest age groups, including a clear anticipatory lateral tilt of the pelvis and the stance leg, which enabled the child to unload the opposite leg shortly before its swing phase. An anticipatory activation of the hip abductor of the leg in stance phase prior to heel-off was found, suggesting pelvis stabilization. APA did not appear consistently until 4-5 years of age. A decrease in segmental oscillations occurred across the ages, indicating better control of intersegmental coordination in the frontal and sagittal planes during the postural phase of gait initiation. Young walkers presented APA involving movements of both the upper and the lower parts of the body, whereas, like adults, 4- to 5-year-olds were able to laterally shift only the pelvis and the stance leg. The oldest children and the adults also showed lower activation levels of hip and knee muscles but higher activation at the ankle level. Those kinematic and EMG results taken together suggest a clear developmental sequence from an en bloc operation of the body through an articulated operation with maturation, walking experience, or both.     

Influence of Destabilization on the Temporal Characteristics of “Volitional” Stepping

Previous work suggests that there may be fundamental differences between compensatory stepping responses evoked by postural perturbation and visually cued “volitional” stepping (e.g., gait initiation). In contrast to visual cueing, postural destabilization evokes an array of sensory inputs that are intrinsically linked to the mobilization of rapid compensatory responses. The hypothesis examined in this study was that this fundamental difference would lead to distinct changes in the temporal characteristics of the stepping response. Six healthy young adults were instructed to step quickly in response to either visual cueing or anterioposterior platform motion. Both forward and backward stepping responses were characterized, using measures of vertical ground reaction force. A stereotypical temporal patterning of the stepping response occurred in both stimulus conditions and both directions of stepping, and anticipatory postural adjustments were evident in all trials. However, postural destabilization led to a more rapid initiation and execution of the temporal pattern, in comparison with visually cued responses. The most pronounced effect was seen in the duration of the response, which was reduced by a factor of two, with approximately proportional foreshortening of both the preparatory and swing phases. The results suggest that sensory information conveying a state of instability has a distinct influence on the characteristics of a subsequent stepping reaction. The persistence of the anticipatory postural adjustments suggests that the failure to see this element of the response in previous studies may reflect fundamental differences between volitional and unplanned compensatory stepping.     

Immediate and Latent Interlimb Transfer of Gait Stability Adaptation Following Repeated Exposure to Slips

The authors trained 21 participants by using blocked-and-mixed exposure to right-side slips and then caused them to slip unexpectedly on the untrained left side. Authors retested participants with a right slip and a left slip at 1 week, 2 weeks, 1 month, and 4 months. The authors found that preslip stability on the first untrained left slip improved and was significantly greater than that on the first right slip, which probably contributed to the reduction in incidence of falls from ~30% to ~10%. Postslip stability and base of support (BOS) slip velocity were similar to those on the first right slip and much lower than those on the last right slip. Increases in pre- and postslip stabilities and BOS slip velocity during the left slip led to reductions in backward balance loss (BLOB) from ~95% on initial left slip to ~60% and to ~25% on the 1st and 3rd retest sessions, respectively. In contrast, BLOB remained at a constant ~40% level on the right slip of the same retest sessions. The results indicate a partial immediate transfer and a possible latent transfer.     

Lower Extremity Kinetics for Balance Control in Children With Cerebral Palsy

The authors examined and compared the effect of support-surface perturbations of various magnitudes on lower extremity kinetics of 7 children with cerebral palsy (CP) and 8 typically developing (TD) children. Results showed that the highest velocity tolerated without stepping was slower in children with CP than in either age-matched TD or younger TD children. Multimodal torque profiles were more frequent in children with CP than in TD controls. TD groups temporally and spatially organized torque activation, whereas children with CP activated all joints simultaneously and showed altered torque contribution patterns among joints. Those results suggest that impairments in reactive postural control in children with CP result not only from developmental delay but also from pathology. Evidence for pathology included increased numbers of torque bursts required to regain stability and less efficient temporal and spatial organization of torque activation patterns.     

An Analysis of Motor Coordination Components for Various Localization Tasks

Localization abilities of subjects in three perceptual-motor tasks were considered before and after an exposure to a visual distortion. During this distortion the subject observed his hand ballistically point to an invisible but audible target while either receiving or not receiving knowledge of results (KR) concerning pointing accuracy. Also, subjects either received a 1-or a 4-sec rest period between each of 30 exposure ballistic pointing actions. The pre-and postexposure tasks involved the ability of a subject to accurately point to an occluded and stationary auditory target, to point to the straight-ahead position in space, and to indicate when a moving, auditory target was perceived as being in the straight-ahead position. For these tasks, the pre-vs. postexposure localization difference scores are referred to as the negative aftereffect, the proprioceptive shift, and the auditory shift, respectively. Wilkinson’s (1971) two-component additive model (negative aftereffect= proprioceptive shift plus auditory shift) held when KR was given regardless of amount of rest between exposure pointing responses. With a 4-sec rest and no KR, the relationship between coordination components was nonadditive (negative aftereffect greater than proprioceptive shift plus auditory shift).     

Effect of Wii-Based Balance Training on Corticomotor Excitability Post Stroke

The objective was to examine the effectiveness of a 3-week balance training program using the Nintendo Wii Fit gaming system (Nintendo Wii Sports, Nintendo, Redmond, WA) on lower limb corticomotor excitability and other clinical measures in chronic stroke survivors. Ten individuals diagnosed with ischemic stroke with residual hemiparesis received balance training using the Wii Fit for 60 min/day, three times/week, for three weeks. At the end of training, an increase in interhemispheric symmetry of corticomotor excitability of the tibialis anterior muscle representations was noted (n = 9). Participants also showed improvements in reaction time, time to perform the Dual Timed-Up-and-Go test, and balance confidence. The training-induced balance in corticomotor excitability suggests that this Wii-based balance training paradigm has the potential to influence neural plasticity and thereby functional recovery.     

Age-Related Changes in Distance From Center of Mass to Center of Pressure During One-Leg Standing

ABSTRACT. The purpose of this study was to clarify the age-related effects of distances from the center of pressure (COP) to the center of mass (COM) (COP-COM distances) during one-leg standing (OLS) task. Healthy old and young adults (n = 11 each) participated in this study. The authors divided the task into 3 phases (accelerated, decelerated, and steady) based on the relationship between COM and COP. COP-COM distances in the older group were significantly reduced during the accelerated phase, then significantly increased during the decelerated and steady phases. Furthermore, distances during these phases correlated inversely with OLS time. The authors conclude that OLS time is shortened by the larger braking response to COM shifts just after leg-lifting, and the production of larger inertial forces to maintain COM position during the OLS in older individuals.