Shoulder elevation affects joint position sense and muscle activation differently in upright and supine body orientations

ObjectiveInvestigate the effects of shoulder elevation on repositioning errors in upright and supine body orientations, and examine these effects on anterior and posterior deltoid muscle activation. We hypothesized decreased errors, and altered anterior and posterior deltoid activation with increasing elevation, in both orientations.DesignCrossover trial.SettingUniversity laboratory.ParticipantsThirty-five college-aged participants.InterventionSubjects attempted to replicate target positions of various elevation angles in upright and supine body orientations. Also, anterior and posterior deltoid activation was recorded in each shoulder position and body orientation.Main outcome measuresVector and variable repositioning errors, anterior and posterior deltoid percentage of maximal contraction.ResultsVector error was greater in supine compared to upright at 90° and 110°, but not at 70°. Variable error was larger in supine than upright, but was unaffected by elevation. Anterior deltoid activation increased with elevation in the upright posture only. Posterior deltoid activation increased with elevation across postures.ConclusionsMuscle activation, external torque, and cutaneous sensations may combine to provide afferent feedback, and be used with centrally-generated signals to interpret the state of the limb during movement. Clinicians may prescribe open kinetic chain exercises in the upright posture with the shoulder elevated approximately 90–100°.     

Older adults exhibit variable responses in stepping behaviour following unexpected forward perturbations during gait initiation

With the socioeconomic burden associated with falls expected to rise as the average age of the Canadian population increases, research is needed to elucidate the nature of postural responses generated by older adults (OA) following a posture-destabilizing event. This knowledge is even more imperative for novel and difficult tasks, such as gait initiation (GI), a task known to pose a postural threat to stability for OA. A common technique to regain stability following an unexpected perturbation is reactive stepping. A deficiency in the execution of a reactive control strategy following a destabilizing event may be the cause of many unexpected falls in OA. The purpose of this study is to explore age related changes in the nature of these responses during a challenging GI task combined with an unexpected forward perturbation of the support surface. A total of 18 young adults (YA) and 16 OA performed 36 trials containing 20 unexpected perturbations. We calculated step width, length, time and COM velocity in the first unperturbed step and the second perturbed step. Results revealed that, during unperturbed GI, OA had a reduced forward velocity and took shorter, faster steps. Following forward perturbations, OA altered stepping patterns, perhaps to reduce single support duration, via reduced base of support and shorter step length compared to YA. Additionally, OA executed both forward and backwards directed steps however YA only generated forward steps. Regression analyses revealed that reduced forward velocity was predictive of step direction; which is possibly an unfavorable motor control strategy as OA who walk slower generated a posterior directed step immediately following the perturbation. This strategy is of concern as rapid responses by the trail limb are required to recover successfully, and these alterations may be associated with an elevated risk of falls.     

Implementation of Expressive Physical Touch in Depressed Older Adults

Depression is a serious problem among older adults and there is limited research on the most effective way to implement and evaluate the effects of expressive touch, either alone or in combination with verbalization, on levels of depression. A convenience sample of 24 institutionalized depressed older adult subjects (15 females and 9 males), ages 67 to 91 years was used for this study. An interrupted time series with multiple replications design was employed with four measurements: Geriatric Depression Scale (GDS), Life-Satisfaction-A-Scale, Rosenburg Self-Esteem Scale, and Locus of Control Scale. Four interventions were implemented: expressive touch only, verbalization only, a combination of expressive touch and verbalization, and a control (presence). Significant differences were found between pretest and posttest scores on the GDS for the expressive touch/verbal intervention. The most comfortable locations to implement the expressive touch and combination interventions were in the dining room or at the subject's bedside. The most comfortable areas of the subjects' bodies touched were the arms, hands, shoulders, and back. Results of this study support an important link between depression, self-esteem, locus of control, and life satisfaction and expressive touch either alone or when combined with talk. Touch as a mode of effective social support may have a therapeutic effect for depressed older adults.     

Older adults exhibit altered motor coordination during an upper limb object transport task requiring a lateral change in support

Investigating an ecologically relevant upper limb task, such as manually transporting an object with a concurrent lateral change in support (sidestepping alongside a kitchen counter), may provide greater insight into potential deficits in postural stability, variability and motor coordination in older adults. Nine healthy young and eleven older, community dwelling adults executed an upper limb object transport task requiring a lateral change in support in two directions at two self-selected speeds, self-paced and fast-paced. Dynamic postural stability and movement variability was quantified via whole-body center of mass motion. The onset of lead lower limb movement in relation to object movement onset was quantified as a measure of motor coordination. Older adults demonstrated similar levels of stability and variability as their younger counterparts, but at slower peak movement velocity and increased task duration. Furthermore, older adults demonstrated asymmetrical motor coordination between left and right task directions, while younger adults remained consistent regardless of task direction. Thus, older adults significantly modulated movement speed and motor coordination to maintain similar levels of stability and variability compared to their younger counterparts.     

Older readers can be distracted by embellishing graphics in text

In most research on graphics in text students learn the content for a test (e.g., Mayer, 2002). The present study examined whether one of the principles from that literature, namely the deleterious effect of extraneous graphic information, would apply to adults who were consulting a leaflet to answer questions. The study used a mixed factorial design with 48 participants from three age bands (young-adult, young-old, old-old). Participants used two leaflets to answer questions, one without graphics and the other with either extraneous embellishing or supportive explanatory graphics. Relative to leaflets without graphics, the old-old participants were significantly slower finding information when leaflets contained embellishing but not explanatory graphics. The graphics had no effect on the other age groups. These findings suggest that either the reading task or the thematic relevance of the extraneous graphics may limit their negative effects for most adults but that negative effects recur for older readers.     

Social anxiety in older adults: phenomenology, prevalence, and measurement

Although phobias represent the most common anxiety disorders among the elderly, little is known about their social nature. The present study provides information about the prevalence, measurement, and phenomenology of social anxiety in older adults (n = 283) and compares results to those of younger adults (n = 318). Analyses revealed that social anxiety is less prevalent in old age than it is within younger cohorts and is associated with different symptomatology. The psychopathological profile of those who reach clinical levels of social anxiety is however similar, irrespective of age. Results regarding the psychometric properties of the SPAI when used for the elderly were promising, but the questionnaire appears to be difficult for some older adults to complete. Results are discussed in terms of explanations for age differences in social anxiety, initial psychometrics of the SPAI in an older adult sample, and suggestions for future research.     

The Role of Spirituality in Advance Directive Decision Making Among Independent Community Dwelling Older Adults

The purpose of this grounded theory study, based on Strauss and Corbin’s (1998) grounded theory methodology, was to investigate the meaning, definition, and needs regarding the role of spirituality in end of life care among independent community dwelling older adults in relation to advance directive decision making (ADDM). Findings revealed that through the use of story telling, independent community dwelling older adults were able to define spirituality and describe the important role spirituality plays in everyday life and in ADDM. A theoretical model was constructed consisting of a mirrored basic social process, Spirituality as Connecting.     

The hypercorrection effect in younger and older adults

ABSTRACT

The hypercorrection effect, which refers to the finding that errors committed with high confidence are more likely to be corrected than are low confidence errors, has been replicated many times, and with both young adults and children. In the present study, we contrasted older with younger adults. Participants answered general-information questions, made confidence ratings about their answers, were given corrective feedback, and then were retested on questions that they had gotten wrong. While younger adults showed the hypercorrection effect, older adults, despite higher overall accuracy on the general-information questions and excellent basic metacognitive ability, showed a diminished hypercorrection effect. Indeed, the correspondence between their confidence in their errors and the probability of correction was not significantly greater than zero, showing, for the first time, that a particular participant population is selectively impaired on this error correction task. These results potentially offer leverage both on the mechanisms underlying the hypercorrection effect and on reasons for older adults’ memory impairments, as well as on memory functions that are spared.     

Control of velocity and position in single joint movements

Previous research on single joint movements has lead to the development of models of control that propose that movement speed and distance are controlled through an initial pulsatile signal that can be modified in both amplitude and duration. However, the manner in which the amplitude and duration are modulated during the control of movement remains controversial. We now report two studies that were designed to differentiate the mechanisms used to control movement speed from those employed to control final position accuracy. In our first study, participants move at a series of speeds to a single spatial target. In this task, acceleration duration (pulse-width) varied substantially across speeds, and was negatively correlated with peak acceleration (pulse-height). In a second experiment, we removed the spatial target, but required movements at the three speeds similar to those used in the first study. In this task, acceleration amplitude varied extensively across the speed targets, while acceleration duration remained constant. Taken together, our current findings demonstrate that pulse-width measures can be modulated independently from pulse-height measures, and that a positive correlation between such measures is not obligatory, even when sampled across a range of movement speeds. In addition, our findings suggest that pulse-height modulation plays a primary role in controlling movement speed and specifying target distance, whereas pulse-width mechanisms are employed to correct errors in pulse-height control, as required to achieve spatial precision in final limb position.     

Exploitation in Older Adults: Personal Competence Correlates of Social Vulnerability

ABSTRACT

Clinical assessment of older people at heightened risk of financial exploitation (also termed social vulnerability) is a difficult task. There are a number of previously untested domains of personal competence which could influence social vulnerability in later life. In this study, intellectual, cognitive, and social-cognitive functioning was assessed in a combined sample of dementia patients (n = 31) and neurologically healthy individuals (n = 68) aged 50 years or over. Informants provided assessments of participants' social functioning, personality, and social vulnerability. In the combined sample, multiple regression analyses revealed significant relationships between each personal competence domain and (lower) social vulnerability, apart from personality which was non-significant. General cognitive functioning and, in particular, executive functioning showed significant overlap with social vulnerability after controlling for memory and age. Social measures were also important correlates of vulnerability, indicating that both neurocognitive and social cognitive deficits may contribute to financial exploitation in later life.     

The role of executive functioning in CBT: a pilot study with anxious older adults

Cognitive behavior therapy (CBT) is an effective treatment for late life anxiety and depression. The successful use of CBT is assumed to rely on cognitive skills known as executive functions (EF; e.g., hypothesis generation, allocation of attention, self-monitoring) governed by the prefrontal cortex. Because older adults sometimes have executive deficits as a consequence of normal aging, EF may be a mediator of CBT outcome in older samples. The current pilot study tested the hypothesis that older adults with executive deficits (as measured by neuropsychological tests) would show decreased therapeutic benefit from CBT for generalized anxiety disorder, as compared to a group with intact EF. Results indicated differential response to CBT within the dysfunction group depending on the stability (and possibly, the etiology) of executive deficits from pre- to posttreatment. Those whose EF scores remained low from pre- to posttreatment did not respond to CBT, while those whose scores improved responded quite well, similar to an Intact EF group. Results indicate that some, but not all, older adults with executive dysfunction show decreased benefit from CBT, and are consistent with the assumption that executive skills are important for the successful use of CBT. However, some participants may show improvement on both mood and cognitive skills during treatment, which is discussed further.     

Positive Gaze Preferences in Older Adults: Assessing the Role of Cognitive Effort with Pupil Dilation

ABSTRACT

Older adults display positive preferences in their gaze, consistent with their prioritization of emotion regulation goals. While some research has argued that substantial amounts of cognitive effort are necessary for these information-processing preferences to occur, other work suggests that these attentional patterns unfold with minimal cognitive exertion. The current study used an implicit regulatory context (i.e., viewing facial stimuli of varying emotions) to assess how much cognitive effort was required for positive attentional preferences to occur. Effortful cognitive processing was assessed with a direct measure of change in pupil dilation. Results indicated that minimal cognitive effort was expended when older adults engaged in positive gaze preferences. This finding suggests that gaze acts as a rather effortless and economical regulatory tool for individuals to shape their affective experience.     

The association of physical activity to neural adaptability during visuo-spatial processing in healthy elderly adults: A multiscale entropy analysis

Physical activity has been shown to benefit brain and cognition in late adulthood. However, this effect is still unexplored in terms of brain signal complexity, which reflects the level of neural adaptability and efficiency during cognitive processing that cannot be acquired via averaged neuroelectric signals. Here we employed multiscale entropy analysis (MSE) of electroencephalography (EEG), a new approach that conveys important information related to the temporal dynamics of brain signal complexity across multiple time scales, to reveal the association of physical activity with neural adaptability and efficiency in elderly adults. A between-subjects design that included 24 participants (aged 66.63 ± 1.31 years; female = 12) with high physical activity and 24 age- and gender-matched low physical activity participants (aged 67.29 ± 1.20 years) was conducted to examine differences related to physical activity in performance and MSE of EEG signals during a visuo-spatial cognition task. We observed that physically active elderly adults had better accuracy on both visuo-spatial attention and working memory conditions relative to their sedentary counterparts. Additionally, these physically active elderly adults displayed greater MSE values at larger time scales at the Fz electrode in both attention and memory conditions. The results suggest that physical activity may be beneficial for adaptability of brain systems in tasks involving visuo-spatial information. MSE thus might be a promising approach to test the effects of the benefits of exercise on cognition.     

Competitive Memory Training for treating depression and rumination in depressed older adults: a randomized controlled trial

Although rumination is an important mediator of depressive symptoms, there is insufficient proof that an intervention that specifically targets rumination ameliorates the clinical condition of, depressed patients. This study investigates whether a time-limited cognitive behavioral intervention (Competitive Memory Training, or COMET for depressive rumination) is an effective treatment for depression and rumination. This intervention was tested in older adult depressed outpatients. A total of 93 patients (aged ≥65 years with major depression and suffering from rumination) were treated in small groups according to the COMET protocol in addition to their regular treatment. Patients were randomized to two treatment conditions: 7 weeks of COMET + treatment-as-usual (TAU) versus TAU only. COMET + TAU showed a significant improvement in depression and rumination compared with TAU alone. This study shows that the transdiagnostic COMET protocol for depressive rumination might also be successful in treating depression and rumination in older adults.     

The Relationship between Everyday Problem Solving and Inconsistency in Reaction Time in Older Adults

ABSTRACT

The purpose of the present study was to investigate whether inconsistency in reaction time (RT) is predictive of older adults' ability to solve everyday problems. A sample of 304 community dwelling non-demented older adults, ranging in age from 62 to 92, completed a measure of everyday problem solving, the Everyday Problems Test (EPT). Inconsistency in latencies across trials was assessed on four RT tasks. Performance on the EPT was found to vary according to age and cognitive status. Both mean latencies and inconsistency were significantly associated with EPT performance, such that slower and more inconsistent RTs were associated with poorer everyday problem solving abilities. Even after accounting for age, education, and mean level of performance, inconsistency in reaction time continued to account for a significant proportion of the variance in EPT scores. These findings suggest that indicators of inconsistency in RT may be of functional relevance.     

Dispositional mindfulness and the wandering mind: Implications for attentional control in older adults

Age-related cognitive decline brings decreases in functional status. Dispositional mindfulness, the tendency towards present-moment attention, is hypothesized to correspond with enhanced attention, whereas mind-wandering may be detrimental to cognition. The relationships among mindfulness, task-related and task-unrelated thought, and attentional control performance on Go/No-Go and Continuous Performance tasks were examined in older adults. Dispositional mindfulness was negatively associated with task-unrelated thought and was positively associated with reactive control, but not proactive control or Go/No-Go performance. Although mind-wandering was not directly associated with performance, task-unrelated thought mediated the mindfulness-proactive control relation. Fewer task-unrelated thoughts were associated with lower proactive control. Interestingly, this effect was moderated by working memory such that it was present for those with low-average, but not high, working memory. This study highlights the importance of dispositional mindfulness and mind-wandering propensity in accounting for individual differences in attentional control in older adults, providing important targets for future cognitive remediation interventions.     

Dual-task effects of simulated lane navigation and story recall in older adults with and without memory impairment

ABSTRACT

While driving is a complex task, it becomes relatively automatic over time although unfamiliar situations require increased cognitive effort. Much research has examined driving risk in cognitively impaired elders and found little effect. This study assessed whether mildly memory impaired elders made disproportionate errors in driving or story recall, under simultaneous simulated driving and story recall. Forty-six healthy (61% women; mean age = 76.4) and 15 memory impaired (66% women, mean age = 79.4) elders participated. Cognitive status was determined by neuropsychological performance. Results showed that during dual-task conditions, participants stayed in lane more, and recalled stories more poorly, than when they did the tasks separately. Follow-up analysis revealed that verbatim recall, in particular, was reduced while driving for healthy participants. While memory impaired participants performed more poorly than healthy controls on both tasks, cognitive status was not associated with greater dual-task costs when driving and story recall were combined.     

Exercises focusing on rotator cuff and scapular muscles do not improve shoulder joint position sense in healthy subjects

Proprioception is essential for shoulder neuromuscular control and shoulder stability. Exercise of the rotator cuff and scapulothoracic muscles is an important part of shoulder rehabilitation. The purpose of this study was to investigate the effect of rotator cuff and scapulothoracic muscle exercises on shoulder joint position sense. Thirty-six healthy subjects were recruited and randomly assigned into either a control or training group. The subjects in the training group received closed-chain and open-chain exercises focusing on rotator cuff and scapulothoracic muscles for four weeks. Shoulder joint position sense errors in elevation, including the humerothoracic, glenohumeral and scapulothoracic joints, was measured. After four weeks of exercise training, strength increased overall in the training group, which demonstrated the effect of exercise on the muscular system. However, the changes in shoulder joint position sense errors in any individual joint of the subjects in the training group were not different from those of the control subjects. Therefore, exercises specifically targeting individual muscles with low intensity may not be sufficient to improve shoulder joint position sense in healthy subjects. Future work is needed to further investigate which types of exercise are more effective in improving joint position sense, and the mechanisms associated with those changes.     

Training attentional control in older adults

ABSTRACT

Recent research has demonstrated benefits for older adults from training attentional control using a variable priority strategy, but the construct validity of the training task and the degree to which benefits of training transfer to other contexts are unclear. The goal of this study was to characterize baseline performance on the training task in a sample of 105 healthy older adults and to test for transfer of training in a subset (n?=?21). Training gains after 5 days and extent of transfer was compared to another subset (n?=?20) that served as a control group. Baseline performance on the training task was characterized by a two-factor model of working memory and processing speed. Processing speed correlated with the training task. Training gains in speed and accuracy were reliable and robust (ps <.001, η²?=?.57 to .90). Transfer to an analogous task was observed (ps <.05, η²?=?.10 to .17). The beneficial effect of training did not translate to improved performance on related measures of processing speed. This study highlights the robust effect of training and transfer to a similar context using a variable priority training task. Although processing speed is an important aspect of the training task, training benefit is either related to an untested aspect of the training task or transfer of training is limited to the training context.     

Behavioral treatment of insomnia in older adults: an open clinical trial comparing two interventions

Fifty-five insomniacs, 60 years or above, participated in a behavioral treatment program, comparing two interventions (sleep hygiene+stimulus control vs sleep hygiene+relaxation tape). Half of the subjects were randomized to a waiting-list condition prior to treatment. No significant changes were observed during the waiting-list period. During the treatment period however, the subjects improved on several sleep parameters, and treatment gains were maintained at a 6-month follow-up. The effects of treatment were greater for nocturnal measures (e.g. sleep onset latency and total sleep time) as compared to daytime measures (e.g. life satisfaction, daytime alertness) and not-targeted behavior (medication use). There were no differences in treatment effects for the two interventions.