Practice Effects on Motor Control in Healthy Seniors and Patients with Mild Cognitive Impairment and Alzheimer's Disease

ABSTRACT

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.     

Dependence on Visual Feedback During Motor Skill Learning in Alzheimer's Disease

Three experiments examined the role of visual feedback on the performance of a fine motor task, namely the rotary pursuit, in patients with Alzheimer's disease (AD) and healthy older adults. After extensive practice tracking a fully visible target, participants in Experiments 1 and 2 were tested under restricted vision (RV) conditions. In both experiments, the two groups showed a drop in performance when vision was restricted, with AD patients showing a significantly larger decline. Tracking improved significantly in normal controls, but not AD patients across the RV trials after the initial drop. When difficulty of the rotary pursuit task was manipulated in Experiment 3 without restricting vision, AD patients and normal controls showed identical patterns of performance. Consequently, it could be concluded that AD patients in the first two experiments were relying more heavily on visual information for accurate performance of the tracking task than their healthy peers.     

Why Do Churches Become Empty,While New Age Grows? Secularization and Religious Change in the Netherlands

Research from the Netherlands has pointed out that the increased popularity of New Age since the 1960s by no means compensates for the dramatic decline of the Christian churches. From a theoretical point of view, however, it is more important to study why those remarkably divergent developments have occurred in the first place. This article does this by analyzing survey data collected among the Dutch population at large in 1998, focusing on a comparison of the young and the elderly. It is concluded, first, that there are no indications that the decline of the Christian tradition has been caused by a process of rationalization. Second, the decline of the Christian tradition and the growth of nonreligiosity as well as New Age are caused by increased levels of moral individualism (individualization). Implications for the sociological analysis of cultural and religious change are discussed.     

Effect of eye movements on backward masking and perceived location

A typical trial of this masking experiment involves, in quick succession, presentation of five letters, evocation of an eye movement, and presentation of a spatially localized mask, either a visual-pattern mask or a metacontrast ring. The effect of the mask is to sappress the report of the letter that stimulates the same retinal location, even though the mask appears to cover or surround the letter whose position in real space it shares. Masking is. however, weaker when the eyes move than when they do not. An auxiliary experiment suggests that the spatial aspects of observable (reportable by S) stimulus persistence are unaffected by eye movements, and therefore that observable persistence differs from that susceptible to masking.     

Processing time for naming and categorization of letters and numbers

A reaction-time experiment was carried out to examine the relationship between naming and categorization. Ss were shown one item at a time and asked either to name the item or to categorize the item as a letter or number. The size of the stimulus set was varied systematically across Ss. Naming time increased as the stimulus set size increased; categorization time could be predicted by the time required for naming, plus a constant. These results were interpreted as indicating that naming must precede categorization.     

Iconic memory and its relation to perceptual processing and other memory mechanisms

Research on iconic memory is reviewed. Specific issues discussed include the duration of the icon, effects of stimulus variables, types of information lost, selection, processing capacity, and scanning. More general issues include the level of encoding in the icon and its relation to short-term memory. It is also argued that a number of experiments do not show what they were intended to show because of possible methodological problems. The view is developed that iconic memory is postretinal but uncoded; nor is it influenced directly by strategies or subsequent mechanisms.     

Sustainable Family Care for Children with Disabilities

The majority of parents want to continue caring for their sons and daughters with disabilities at home, and they are expected and actively encouraged to do so. Notwithstanding, and for reasons that are not well understood, a substantial number of parents seek to place their disabled son or daughter out-of-home. The aim of this study was to investigate the attitudes of parent-carers in Alberta, Canada, toward out-of-home placement. The primary objective was to identify factors that may explain why some families, and not others, seriously consider out-of-home placement as an option for their child. This knowledge is vital for developing social care policies and programs that support parents and promote sustainable family care for children with disabilities. A stratified (by child age group) random sample of 538 families raising children with disabilities in Alberta, Canada took part. Participants completed the family life survey, which incorporated measures of child and family characteristics, sustainability of the daily routine, and out-of-home placement propensity. Results suggest that family placement propensity is inversely associated with the sustainability of the daily routine. Sustainability of the daily routine is, in turn, more strongly associated with social-ecological resources, including parental control-over-work and the adequacy of child care options, than with child characteristics, including activity limitations and behaviour problems. If families have the social-ecological resources they need to create and maintain a daily routine that is congruent with their values and goals, and with the needs, interests and competences of family members, then they are unlikely to give out-of-home placement any serious consideration.     

LearningRx Cognitive Training Effects in Children Ages 8–14: A Randomized Controlled Trial

In a randomized controlled study, we examined the effects of a one‐on‐one cognitive training program on memory, visual and auditory processing, processing speed, reasoning, attention, and General Intellectual Ability (GIA) score for students ages 8–14. Participants were randomly assigned to either an experimental group to complete 60 h of cognitive training or to a wait‐list control group. The purpose of the study was to examine changes in multiple cognitive skills after completing cognitive training with ThinkRx, a LearningRx program. Results showed statistically significant differences between groups on all outcome measures except for attention. Implications, limitations, and suggestions for future research are examined. © 2016 The Authors Applied Cognitive Psychology Published by John Wiley & Sons Ltd.     

Laterality of the frontal aslant tract (FAT) explains externalizing behaviors through its association with executive function

We investigated the development of a recently identified white matter pathway, the frontal aslant tract (FAT) and its association with executive function and externalizing behaviors in a sample of 129 neurotypical male and female human children ranging in age from 7 months to 19 years. We found that the FAT could be tracked in 92% of those children, and that the pathway showed age‐related differences into adulthood. The change in white matter microstructure was very rapid until about 6 years, and then plateaued, only to show age‐related increases again after the age of 11 years. In a subset of those children (5–18 years; n = 70), left laterality of the microstructural properties of the FAT was associated with greater attention problems as measured by the Child Behavior Checklist (CBCL). However, this relationship was fully mediated by higher executive dysfunction as measured by the Behavior Rating Inventory of Executive Function (BRIEF). This relationship was specific to the FAT—we found no relationship between laterality of a control pathway, or of the white matter of the brain in general, and attention and executive function. These findings suggest that the degree to which the developing brain favors a right lateralized structural dominance of the FAT is directly associated with executive function and attention. This novel finding provides a new potential structural biomarker to assess attention deficit hyperactivity disorder (ADHD) and associated executive dysfunction during development.     

Episodic memory function is affected by lifestyle factors: a 14-year follow-up study in an elderly population

Understanding the relationship between memory function and lifestyle offers great opportunities for promoting beneficial lifestyle choices to foster healthy cognitive aging and for the development of intervention programs for older adults. We studied a cohort of older adults (age 65 and older) enrolled in the Longitudinal Aging Study Amsterdam, an ongoing prospective population-based research project. A total of 1,966 men and women participated in an episodic memory test every 3 years over a period of 14 years. Lifestyle habits were repeatedly assessed using self-report measures. Physical activity, light-to-moderate alcohol consumption, difficulties staying asleep, and social engagement were associated with better memory function over the course of 14 years. In contrast, smoking and long sleep duration were associated with worse memory function. These findings suggest that certain lifestyle factors can have long-term protective or harmful effects on memory function in aging individuals.