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Age-related decline in executive functions and postural control due to degenerative processes in the central nervous system have been related to increased fall-risk in old age. Many studies have shown cognitive-postural dual-task interference in old adults, but research on the role of specific executive functions in this context has just begun. In this study, we addressed the question whether postural control is impaired depending on the coordination of concurrent response-selection processes related to the compatibility of input and output modality mappings as compared to impairments related to working-memory load in the comparison of cognitive dual and single tasks. Specifically, we measured total center of pressure (CoP) displacements in healthy female participants aged 19–30 and 66–84 years while they performed different versions of a spatial one-back working memory task during semi-tandem stance on an unstable surface (i.e., balance pad) while standing on a force plate. The specific working-memory tasks comprised: (i) modality compatible single tasks (i.e., visual-manual or auditory-vocal tasks), (ii) modality compatible dual tasks (i.e., visual-manual and auditory-vocal tasks), (iii) modality incompatible single tasks (i.e., visual-vocal or auditory-manual tasks), and (iv) modality incompatible dual tasks (i.e., visual-vocal and auditory-manual tasks). In addition, participants performed the same tasks while sitting. As expected from previous research, old adults showed generally impaired performance under high working-memory load (i.e., dual vs. single one-back task). In addition, modality compatibility affected one-back performance in dual-task but not in single-task conditions with strikingly pronounced impairments in old adults. Notably, the modality incompatible dual task also resulted in a selective increase in total CoP displacements compared to the modality compatible dual task in the old but not in the young participants. These results suggest that in addition to effects of working-memory load, processes related to simultaneously overcoming special linkages between input- and output modalities interfere with postural control in old but not in young female adults. Our preliminary data provide further evidence for the involvement of cognitive control processes in postural tasks.
Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60–72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality (p < 0.05) and the auditory modality (p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination.
The aim was to analyze the risk of hip fracture in German primary care patients with dementia. This study included patients aged 65-90 from 1072 primary care practices who were first diagnosed with dementia between 2010 and 2013. Controls were matched (1:1) to cases for age, sex, and type of health insurance. The primary outcome was the diagnosis of hip fracture during the three-year follow-up period. A total of 53,156 dementia patients and 53,156 controls were included. A total of 5.3% of patients and 0.7% of controls displayed hip fracture after three years. Hip fracture occurred more frequently in dementia subjects living in nursing homes than in those living at home (9.2% versus 4.3%). Dementia, residence in nursing homes, and osteoporosis were risk factors for fracture development. Antidementia, antipsychotic, and antidepressant drugs generally had no significant impact on hip fracture risk when prescribed for less than six months. Dementia increased hip fracture risk in German primary care practices.
The aim was to analyze the risk of hip fracture in German primary care patients with dementia. This study included patients aged 65-90 from 1072 primary care practices who were first diagnosed with dementia between 2010 and 2013. Controls were matched (1:1) to cases for age, sex, and type of health insurance. The primary outcome was the diagnosis of hip fracture during the three-year follow-up period. A total of 53,156 dementia patients and 53,156 controls were included. A total of 5.3% of patients and 0.7% of controls displayed hip fracture after three years. Hip fracture occurred more frequently in dementia subjects living in nursing homes than in those living at home (9.2% versus 4.3%). Dementia, residence in nursing homes, and osteoporosis were risk factors for fracture development. Antidementia, antipsychotic, and antidepressant drugs generally had no significant impact on hip fracture risk when prescribed for less than six months. Dementia increased hip fracture risk in German primary care practices.
Age-related decline in executive functions and postural control due to degenerative processes in the central nervous system have been related to increased fall-risk in old age. Many studies have shown cognitive-postural dual-task interference in old adults, but research on the role of specific executive functions in this context has just begun. In this study, we addressed the question whether postural control is impaired depending on the coordination of concurrent response-selection processes related to the compatibility of input and output modality mappings as compared to impairments related to working-memory load in the comparison of cognitive dual and single tasks. Specifically, we measured total center of pressure (CoP) displacements in healthy female participants aged 19–30 and 66–84 years while they performed different versions of a spatial one-back working memory task during semi-tandem stance on an unstable surface (i.e., balance pad) while standing on a force plate. The specific working-memory tasks comprised: (i) modality compatible single tasks (i.e., visual-manual or auditory-vocal tasks), (ii) modality compatible dual tasks (i.e., visual-manual and auditory-vocal tasks), (iii) modality incompatible single tasks (i.e., visual-vocal or auditory-manual tasks), and (iv) modality incompatible dual tasks (i.e., visual-vocal and auditory-manual tasks). In addition, participants performed the same tasks while sitting. As expected from previous research, old adults showed generally impaired performance under high working-memory load (i.e., dual vs. single one-back task). In addition, modality compatibility affected one-back performance in dual-task but not in single-task conditions with strikingly pronounced impairments in old adults. Notably, the modality incompatible dual task also resulted in a selective increase in total CoP displacements compared to the modality compatible dual task in the old but not in the young participants. These results suggest that in addition to effects of working-memory load, processes related to simultaneously overcoming special linkages between input- and output modalities interfere with postural control in old but not in young female adults. Our preliminary data provide further evidence for the involvement of cognitive control processes in postural tasks.
Background: The aim of the present study was to investigate the psychometric characteristics of the Perceived Stress Scale (PSS) in a sample of dementia patients and their spousal caregivers. Methods: We investigated the reliability and validity of the 14-item PSS in a sample of 80 couples, each including one spouse who had been diagnosed with mild to moderate dementia (mean age 75.55, SD = 5.85, 38.7% female) and one spousal caregiver (mean age 73.06, SD = 6.75, 61.3% female). We also examined the factor structure and sensitivity of the scale with regard to gender differences. Results: Exploratory factor analysis of the PSS revealed a two-factor solution for the scale; the first factor reflected general stress while the second factor consisted of items reflecting the perceived ability to cope with stressors. A confirmatory factor analysis verified that the data were a better fit for the two-factor model than a one-factor model. The two factors of the PSS showed good reliability for patients as well as for caregivers ranging between alpha = 0.73 and alpha = 0.82. Perceived stress was significantly positively correlated with depressive symptomatology in both caregivers and patients. Mean PSS scores did not significantly differ between male and female patients nor did they differ between male and female caregivers. Conclusion: The present data indicate that the PSS provides a reliable and valid measure of perceived stress in dementia patients and their caregivers.
Objectives: In patients with early-stage dementia and their caregiving partners, reciprocal dyadic coping (DC) is crucial for preventing or reducing depressive symptoms in both partners. This study examines the relationships between ‘own DC’ and ‘perceived partner DC’ with depressive symptoms in couples coping with dementia on individual (actor effects) and cross-person (partner effects) levels.
Method: 164 individuals (82 patients with early-stage dementia and their 82 caregiving partners; ND = 82 dyads) participated in this prospective study with measures (DC, depressive symptoms, and dementia severity) taken at baseline and at six months. Each partner evaluated their own and the perceived partner DC. Actor–partner interdependence models were applied to the resulting four independent evaluations.
Results: Results differed substantially between patients and caregivers. DC was significantly related to patients’ but not to caregivers’ depressive symptoms, when adjustments were made for individual coping. Perceived partner DC showed a negative association with depressive symptoms in patients, whereas own DC was adversely related for actor as well as for partner effects across individuals.
Conclusion: The adverse association between the own DC of the caregiver and the patient on depressive symptoms of the patient might be due to inappropriate efforts or to the loss of autonomy as a care-receiver. DC is important in both patients and caregivers, as shown by the negative association between perceived partner DC and depressive symptoms in the patients, which might inform interventions that target the couple as a whole.
Background/Aims: Even though cognitive behavioral therapy has become a relatively effective treatment for major depressive disorder and cognitive behavioral therapy-related changes of dysfunctional neural activations were shown in recent studies, remission rates still remain at an insufficient level. Therefore, the implementation of effective augmentation strategies is needed. In recent meta-analyses, exercise therapy (especially endurance exercise) was reported to be an effective intervention in major depressive disorder. Despite these findings, underlying mechanisms of the antidepressant effect of exercise especially in combination with cognitive behavioral therapy have rarely been studied to date and an investigation of its neural underpinnings is lacking. A better understanding of the psychological and neural mechanisms of exercise and cognitive behavioral therapy would be important for developing optimal treatment strategies in depression. The SPeED study (Sport/Exercise Therapy and Psychotherapyevaluating treatment Effects in Depressive patients) is a randomized controlled trial to investigate underlying physiological, neurobiological, and psychological mechanisms of the augmentation of cognitive behavioral therapy with endurance exercise. It is investigated if a preceding endurance exercise program will enhance the effect of a subsequent cognitive behavioral therapy. Methods: This study will include 105 patients diagnosed with a mild or moderate depressive episode according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed.). The participants are randomized into one of three groups: a high-intensive or a low-intensive endurance exercise group or a waiting list control group. After the exercise program/waiting period, all patients receive an outpatient cognitive behavioral therapy treatment according to a standardized therapy manual. At four measurement points, major depressive disorder symptoms (Beck Depression Inventory, Hamilton Rating Scale for Depression), (neuro)biological measures (neural activations during working memory, monetary incentive delay task, and emotion regulation, as well as cortisol levels and brain-derived neurotrophic factor), neuropsychological test performance, and questionnaires (psychological needs, self-efficacy, and quality of life) are assessed. Results: In this article, we report the design of the SPeED study and refer to important methodological issues such as including both high- and low-intensity endurance exercise groups to allow the investigation of dose-response effects and physiological components of the therapy effects. Conclusion: The main aims of this research project are to study effects of endurance exercise and cognitive behavioral therapy on depressive symptoms and to investigate underlying physiological and neurobiological mechanisms of these effects. Results may provide important implications for the development of effective treatment strategies in major depressive disorder, specifically concerning the augmentation of cognitive behavioral therapy by endurance exercise.
Rationale: Advances in neurocomputational modeling suggest that valuation systems for goal-directed (deliberative) on one side, and habitual (automatic) decision-making on the other side may rely on distinct computational strategies for reinforcement learning, namely model-free vs. model-based learning. As a key theoretical difference, the model-based system strongly demands cognitive functions to plan actions prospectively based on an internal cognitive model of the environment, whereas valuation in the model-free system relies on rather simple learning rules from operant conditioning to retrospectively associate actions with their outcomes and is thus cognitively less demanding. Acute stress reactivity is known to impair model-based but not model-free choice behavior, with higher working memory capacity protecting the model-based system from acute stress. However, it is not clear which impact accumulated real life stress has on model-free and model-based decision systems and how this influence interacts with cognitive abilities. Methods: We used a sequential decision-making task distinguishing relative contributions of both learning strategies to choice behavior, the Social Readjustment Rating Scale questionnaire to assess accumulated real life stress, and the Digit Symbol Substitution Test to test cognitive speed in 95 healthy subjects. Results: Individuals reporting high stress exposure who had low cognitive speed showed reduced model-based but increased model-free behavioral control. In contrast, subjects exposed to accumulated real life stress with high cognitive speed displayed increased model-based performance but reduced model-free control. Conclusion: These findings suggest that accumulated real life stress exposure can enhance reliance on cognitive speed for model-based computations, which may ultimately protect the model-based system from the detrimental influences of accumulated real life stress. The combination of accumulated real life stress exposure and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities.