Normal aging is associated with alterations of functional connectivity (FC) in brain neuronal networks. Altered network connectivity may be associated with accelerated cognitive decline. Physical activity is considered a beneficial lifestyle factor for maintaining cognitive health. Higher intensities of physical activity may induce structural and functional changes in the brain, particularly in regions involved in cognitive functions, such as memory, attention and executive functions. However, the underlying neural mechanisms are not widely investigated. Our aim was to examine the association between resting-state FC of brain networks and baseline physical activity in healthy older adults. We analyzed baseline resting-state fMRI and baseline physical activity data of 149 healthy older adults (mean age: 68 years) from the AgeGain study. Physical activity was measured by using actigraphs worn for 7 days. Different intensities were measured, such as light, mean and moderate-to-vigorous activity (min/d). We used Independent Component Analysis (ICA) and seed-based approaches to examine brain network activity in the Default Mode Network (DMN), Salience Network (SAL), Central Executive Network (CEN), Visual Network (VN) for cognitive effects and Sensorimotor Network (SMN) for physical effects. We observed statistically significant associations between functional activation within SMN and light physical activity and spatially restricted effects for DMN and moderate-to-vigorous physical activity ( p <.01 uncorrected). In addition, we observed an overlap on frontal activation across DMN, SMN and SAL. Results of the seed-based analysis will be presented at the conference. Light to higher intensities of physical activity showed an association with higher functional activation of networks previously associated with cognitive decline and physical activity. This agrees with the notion that physical activity may be a protective factor against cognitive decline. Further research is needed to test the replicability of these results.

Age-related cognitive decline increase the need for cognitive interventions to maintain cognitive function. Transfer of training gains to untrained tasks is a key indicator for the effectiveness of cognitive training. However, the underlying brain mechanisms need to be further investigated. We implemented a cognitive training study to assess functional connectivity determinants of transfer of training gains. A sample of 181 healthy older adults (mean age: 68 years) underwent a 4-week cognitive training across three sites. The control group consisted of 54 older adults. To evaluate transfer and training effects, participants underwent a neuropsychological assessment before and after the training. A second follow-up assessment was applied 12 weeks after the training. The training group was divided in subjects who had and who did not have successful transfer, which was defined as higher improvement in cognitive tasks than the control group. We used cognitive scores representing working memory, verbal and visuospatial memory and executive functions. Baseline resting-state functional magnetic resonance imaging was assessed in order to investigate the functional connectivity of brain networks associated with cognitive functions. Cognitive performance of the training group remained stable across time and did not show a significant improvement. Transfer of training gains directly after the training was limited. However, our participants were able to maintain gains 12 weeks after the training. We hypothesized a higher functional connectivity of brain networks, such as Default Mode Network or the Executive Network, to be associated with successful transfer of cognitive gains. Investigation of brain networks activity and the association with transfer of training gains is currently ongoing and complete results will be presented at the conference. Transfer of training gains in aging is possible, but it remains limited. Cognitively healthy older adults might not have major benefits from a 4-week cognitive training. Our results could help to identify healthy older adults who will most benefit from training and understand the brain mechanisms underlying transfer of cognitive gains.

ObjectiveTo determine whether gait and accelerometric features can predict disorientation events in young and older adults.MethodsCognitively healthy younger (18–40 years, n = 25) and older (60–85 years, n = 28) participants navigated on a treadmill through a virtual representation of the city of Rostock featured within the Gait Real-Time Analysis Interactive Lab (GRAIL) system. We conducted Bayesian Poisson regression to determine the association of navigation performance with domain-specific cognitive functions. We determined associations of gait and accelerometric features with disorientation events in real-time data using Bayesian generalized mixed effect models. The accuracy of gait and accelerometric features to predict disorientation events was determined using cross-validated support vector machines (SVM) and Hidden Markov models (HMM).ResultsBayesian analysis revealed strong evidence for the effect of gait and accelerometric features on disorientation. The evidence supported a relationship between executive functions but not visuospatial abilities and perspective taking with navigation performance. Despite these effects, the cross-validated percentage of correctly assigned instances of disorientation was only 72% in the SVM and 63% in the HMM analysis using gait and accelerometric features as predictors.ConclusionDisorientation is reflected in spatiotemporal gait features and the accelerometric signal as a potentially more easily accessible surrogate for gait features. At the same time, such measurements probably need to be enriched with other parameters to be sufficiently accurate for individual prediction of disorientation events.

Background: Normal aging is associated with working memory decline. A decrease in working memory performance is associated with age-related changes in functional activation patterns in the dorsolateral prefrontal cortex (DLPFC). Cognitive training can improve cognitive performance in healthy older adults. We implemented a cognitive training study to assess determinants of generalization of training gains to untrained tasks, a key indicator for the effectiveness of cognitive training. We aimed to investigate the association of resting-state functional connectivity (FC) of DLPFC with working memory performance improvement and cognitive gains after the training. Method: A sample of 60 healthy older adults (mean age: 68 years) underwent a 4-week neuropsychological training, entailing a working memory task. Baseline resting-state functional MRI (rs-fMRI) images were acquired in order to investigate the FC of DLPFC. To evaluate training effects, participants underwent a neuropsychological assessment before and after the training. A second follow-up assessment was applied 12 weeks after the training. We used cognitive scores of digit span backward and visual block span backward tasks representing working memory function. The training group was divided into subjects who had and who did not have training gains, which was defined as a higher improvement in working memory tasks than the control group ( N = 19). Results: A high FC of DLPFC of the right hemisphere was significantly associated with training gains and performance improvement in the visuospatial task. The maintenance of cognitive gains was restricted to the time period directly after the training. The training group showed performance improvement in the digit span backward task. Conclusion: Functional activation patterns of the DLPFC were associated with the degree of working memory training gains and visuospatial performance improvement. Although improvement through cognitive training and acquisition of training gains are possible in aging, they remain limited.

Cognitive training can improve cognitive performance in healthy older adults. The effectiveness of a training is considered as a maintenance of training skills outside of a training context. Research data indicate an association between cognitive decline and changes of brain function in normal aging. A better understanding of the brain mechanisms that can enhance or preserve cognitive training skills could help identifying healthy older adults who will benefit from cognitive interventions. The cholinergic basal forebrain is involved in several aspects of cognition including attention. In our study, we aimed to assess the association of functional connectivity of the basal forebrain with maintained training skills. A sample of 60 healthy older adults (mean age: 68 years) underwent a 4-week multi-modal cognitive training and neuropsychological assessments before and after the training. A second follow-up assessment was applied 12 weeks after the training. Baseline resting-state functional magnetic resonance imaging was used to derive the global functional connectivity of the anterior-medial and posterior-lateral compartments of the basal forebrain. We focused on attention capacities using the Test battery for Attention Performance (TAP), which assesses a variety of attentional aspects, including alertness. Maintenance of training gains was defined as higher improvement in the alertness tasks after 12 weeks than a no-training control group. A high functional connectivity of anterior basal forebrain was a significantly associated with maintenance of training gains in the phasic arousal tasks, i.e. the reaction time in response to a critical stimulus preceded by a cue stimulus presented as a warning tone. There was no significant association for the posterior basal forebrain. Functional activation patterns of basal forebrain contribute to maintenance of training gains of alertness tasks.