Evaluating Co-construction in Dyadic Conversations: A Pilot Study on Older Adults with Dementia and Healthy Older Adults in Taiwan.

Older adults' daily conversations with other older adults enable them to connect to their surrounding communities and improve their friendships. However, typical aging processes and fluctuations in family caring might cause conversation changes. The purpose of this study was to explore the quantitative contributions of conversation turns (CTs) and speaking roles (SRs) in Mandarin-Chinese-speaking conversation dyads between mutually familiar healthy older adults (HOAs). A total of 20 HOAs aged 65 or over were recruited. Each dyad conversed for ten minutes once a week for five weeks, five sessions per dyad, for a total of 50 sessions. The frequency and percentages of the coded CTs and SRs contributed by each HOA were individually tallied and calculated. Quantitatively symmetrical contributions of CTs and SRs occurred in Mandarin-Chinese-speaking conversation dyads between mutually familiar HOAs. Although typical aging processes might change conversations, both Mandarin-Chinese-speaking HOAs serve as active interlocutors to each other in taking CTs and SRs to co-construct their conversation processes and content in their dyadic conversation. Sufficient knowledge of conversation co-constructions might lead them to have more supportive environments to connect to surrounding communities and improve their friendships.

This study explored the effect of mutual familiarity of interlocutors on quantitative contributions of conversation turns in dyadic conversation among Mandarin Chinese-speaking older adults. A quantitative quasi-experimental study was conducted. A total of 42 healthy older adults aged 65 years or over were recruited. Percentages of contributed conversation turns for each interlocutor were computed as frequency of interlocutor conversation turns divided by total frequency of dyad conversation turns multiplied by 100. Quantitative asymmetries were differences of percentages of contributed conversation turns. A total of 60 ten-minute dyadic conversation sessions were conducted, including 30 mutually familiar-older-adult sessions (FOAS) and 30 mutually unfamiliar-older-adult sessions (UOAS). Quantitatively asymmetrical contributions of conversation turns occurred in both FOAS and UOAS, and quantitative contributions of conversation turns in FOAS were significantly more asymmetrical than those in UOAS. There were three limitations to the current study, including limited representations of everyday conversation contexts (e.g., at home); no consideration of the types of conversation modes; and no consideration of sensitivity to conversation as one of the inclusion criteria for research participants. Quantitatively asymmetrical contributions of conversation turns occurred in both mutually FOAS and UOAS dyads among Mandarin Chinese-speaking older adults. Moreover, quantitative contributions of conversation turns in mutually FOAS dyads were significantly more asymmetrical than those in mutually UOAS dyads. Sufficient knowledge of changes in conversation turns in dyadic conversation among healthy older adults might reduce misperceptions of older adults suffering from neurological disease.

Exercise Testing and Training Strategies for Healthy and Frail Elderly

Aging is associated with detrimental changes in sleep physiology, a process accelerated in Alzheimer's disease. Fine-tuned temporal interactions of non-rapid eye movement slow oscillations and spindles were shown to be particularly important for memory consolidation, and to deteriorate in healthy older adults. Whether this oscillatory interaction further decline in early stages of Alzheimer's disease such as mild cognitive impairment has not been investigated to date, but may have important therapeutic implications. Here, we assessed differences in sleep architecture and memory-relevant slow oscillation, sleep spindles and their functional coupling during a 90-min nap between healthy young and older adults, and in older patients with mild cognitive impairment. Furthermore, associations of nap-sleep characteristics with sleep-dependent memory performance change were evaluated. We found significant differences between young and older healthy adults, and between young adults and patients with mild cognitive impairment, but not between healthy older adults and patients for several sleep metrics, including slow oscillation-spindle coupling. Moreover, sleep-dependent retention of verbal memories was significantly higher in young healthy adults versus older adults with and without mild cognitive impairment, but no difference between the two older groups was observed. Associations with sleep metrics were only found for pre-nap memory performances. In conclusion, our results indicate changes in nap sleep physiology and sleep-related memory consolidation in older adults with and without mild cognitive impairment. Thus, interventions targeted at improving sleep physiology may help to reduce memory decline in both groups, but our study does not indicate additional benefits for patients with mild cognitive impairment. Effects of Brain Stimulation During Daytime Nap on Memory Consolidation in Younger, Healthy Subjects: https://clinicaltrials.gov/ct2/show/NCT01840865; NCT01840865. Effects of Brain Stimulation During a Daytime Nap on Memory Consolidation in Older Adults; https://clinicaltrials.gov/ct2/show/study/NCT01840839?term=01840839&draw=2&rank=1; NCT01840839. Effects of Brain Stimulation During a Daytime Nap on Memory Consolidation in Patients With Mild Cognitive Impairment; https://clinicaltrials.gov/ct2/show/NCT01782365?term=01782365&draw=2&rank=1; NCT01782365.

Purpose/Hypothesis: The purpose of this study was to characterize differences in the time required to adaptively re-weight visual information following a sudden change in visual motion amplitude in healthy young, healthy older, and fall-prone older adults. Number of Subjects: Tree groups of subjects participated: healthy young adults (ages 20–30 yrs, N=21), healthy older adults (ages 70–93 yrs, N=25), and fall-prone elderly (ages 73–92 yrs, N=17). Materials/Methods: Subjects were exposed to two visual motion conditions in which the amplitude of visual motion stimuli switched from low-to-high or high-to-low. The postural sway responses to this change in visual environment were analyzed (COM gain, phase, position variability and velocity variability). We compared absolute levels of COM gain at, and adaptive gain changes across, selected time intervals and between groups. Changes in gain over time were analyzed using non-linear regression to obtain comparative prolonged rates of change before and after each amplitude switch, and rapid rates of change at each switch. Results: Absolute levels of gain, pre-and post-switch, were consistently higher in both older adult groups than in the young, when the stimulus amplitude was high. Gains were frequently higher in the fall-prone versus healthy older and young adults when the stimulus amplitude was low. For all three groups, adaptive sensory re-weighting was refected by gain changes following stimulus motion amplitude changes. Interestingly, all three groups showed evidence of equally rapid re-weighting at the time of the amplitude switch. Between-group differences were apparent in the prolonged changes in gain. Compared to young adults who usually did not reweight further after the initial rapid adaptation, both older adult groups demonstrated continued gradual changes in gain over time periods of 105 seconds. When the stimulus amplitude was high, both older adult groups demonstrated slower prolonged adaptation rates than the young. Rates of prolonged adaptation were not different between the older groups and the young when the stimulus amplitude was low. Conclusions: Rapid re-weighting when the stimulus amplitude suddenly increases is necessary to prevent instability. All three groups demonstrated functionally adaptive responses. However, down-weighting to high-amplitude stimuli is slower and to a lesser extent in healthy and fall-prone older adults compared to young adults. With low-amplitude stimuli, fall-prone older adults continued to have the highest absolute levels of gain and slowest rates of prolonged change compared to healthy older and young adults. Clinical Relevance: Older adults, especially the fall-prone elderly, may experience relatively heightened periods of postural instability and increased risk of falls until sensory adaptation is complete. It may be possible to increase the adaptation rate, and thus reduce the duration of periods of instability, via sensory-challenge balance exercises; future studies are needed to explore this possibility.

(169) Comparison of Temporal Stability of Conditioned Pain Modulation and Temporal Summation of Pain in Healthy Older and Younger Adults

PurposeEstablish bedside biomarkers of myosteatosis for sarcopenia and cachexia. We compared ultrasound biomarkers against MRI-based percent fat, histology, and CT-based muscle density among healthy adults and adults undergoing treatment for lung cancer.MethodsWe compared ultrasound and MRI myosteatosis measures among young healthy, older healthy, and older adults with non-small cell lung cancer undergoing systemic treatment, all without significant medical concerns, in a cross-sectional pilot study. We assessed each participant's rectus femoris ultrasound-based echo intensity (EI), shear wave elastography-based shear wave speed, and MRI-based proton density fat-fraction (PDFF). We also assessed BMI, rectus femoris thickness and cross-sectional area. Rectus femoris biopsies were taken for all older adults (n = 20) and we analyzed chest CT scans for older adults undergoing treatment (n = 10). We determined associations between muscle assessments and BMI, and compared these assessments between groups.ResultsA total of 10 young healthy adults, 10 older healthy adults, and 10 older adults undergoing treatment were recruited. PDFF was lower in young adults than in older healthy adults and older adults undergoing treatment (0.3 vs. 2.8 vs. 2.9%, respectively, p = 0.01). Young adults had significantly lower EI than older healthy adults, but not older adults undergoing treatment (48.6 vs. 81.8 vs. 75.4, p = 0.02). When comparing associations between measures, PDFF was strongly associated with EI (ρ = 0.75, p < 0.01) and moderately negatively associated with shear wave speed (ρ = −0.49, p < 0.01) but not BMI, whole leg cross-sectional area, or rectus femoris cross-sectional area. Among participants with CT scans, paraspinal muscle density was significantly associated with PDFF (ρ = −0.70, p = 0.023). Histological markers of inflammation or degradation did not differ between older adult groups.ConclusionPDFF was sensitive to myosteatosis between young adults and both older adult groups. EI was less sensitive to myosteatosis between groups, yet EI was strongly associated with PDFF unlike BMI, which is typically used in cachexia diagnosis. Our results suggest that ultrasound measures may serve to determine myosteatosis at the bedside and are more useful diagnostically than traditional weight assessments like BMI. These results show promise of using EI, shear wave speed, and PDFF proxies of myosteatosis as diagnostic and therapeutic biomarkers of sarcopenia and cachexia.

Cognitive function depends on adequate cerebrovascular perfusion and control. However, it is unknown whether acutely-reduced cerebral blood flow (CBF) impairs cognition in healthy adults. In the present study, we used a placebo-controlled, single-blinded, randomized cross-over design to test the hypothesis that acutely-reduced CBF (using a pharmacological aid; indomethacin) would impair cognition in young and older healthy adults. At baseline, older adults had lower cognitive performance and CBF, but similar cerebrovascular reactivity to CO2 and dynamic cerebral autoregulation compared to young adults. In both young and older adults, cognitive performance on a mental switching task was slightly (7%) reduced after indomethacin, but not significantly associated with reductions in CBF (∼31%). These results indicate that cognitive performance is broadly resilient against a ∼31% reduction in CBF per se in healthy young and older adults. Cognitive function depends on adequate cerebrovascular perfusion and control. However, it is unknown whether acutely-reduced cerebral blood flow (CBF) impairs cognition in healthy adults. Using a placebo-controlled, single-blinded, randomized cross-over design, we tested the hypothesis that acutely-reduced CBF (using indomethacin [1.2mgkg-1 oral dose]) would impair cognition in young (n=13; 25±4years) and older (n=12; 58±6years) healthy adults. CBF and cerebrovascular control were measured using middle cerebral artery blood velocity (MCAvmean ) and its reactivity to hypercapnia (CVRHYPER ) and hypocapnia (CVRHYPO ), respectively. Cognitive function was assessed using a computerized battery including response time tasks. Baseline comparisons revealed that older adults had 14% lower MCAvmean and 15% lower cognitive performance (all P≤0.048), but not lower CVRHYPER/HYPO (P≥0.26). Linear and rank-based mixed models revealed that indomethacin decreased MCAvmean by 31% (95% confidence interval=-35 to -26), CVRHYPER by 68% [interquartile range (IQR)=-94 to -44] and CVRHYPO by 50% (IQR=-83 to -33) (treatment-effect; all P<0.01), regardless of age. Baseline CVRHYPER/HYPO values were strongly associated with their indomethacin-induced reductions (r=0.70 to 0.89, P<0.01). Mental switching performance was impaired 7% (IQR=0-19) after indomethacin (P=0.04), but not significantly associated with reductions in MCAvmean (Young: rho=-0.31, P=0.30; Older: rho=0.06, P=0.86). In conclusion, indomethacin reduced MCAvmean and impaired cognition slightly; however, no clear association was evident in younger or older adults. Older adults had poorer cognition and lower MCAvmean , but similar CVRHYPER/HYPO .

IntroductionAge-related decline in episodic memory performance in otherwise healthy older adults is indisputably evident. Yet, it has been shown that under certain conditions episodic memory performance in healthy older adults’ barely deviates from those seen in young adults. Here we report on the quality of object encoding in an ecologically valid, virtual-reality based memory assessment in a sample of healthy older and younger adults with comparable memory performance.MethodsWe analyzed encoding by establishing both a serial and semantic clustering index and an object memory association network.ResultsAs expected, semantic clustering was superior in older adults without need for additional allocation of executive resources whereas young adults tended more to rely on serial strategies. The association networks suggested a plethora of obvious but also less obvious memory organization principles, some of which indicated converging approaches between the groups as suggested by a subgraph analysis and some of which indicated diverging approaches as suggested by the respective network interconnectivity. A higher interconnectivity was observed in the older adults’ association networks.DiscussionWe interpreted this as a consequence of superior semantic memory organization (extent to which effective semantic strategies diverged within the group). In conclusion, these results might indicate a diminished need for compensatory cognitive effort in healthy older adults when encoding and recalling everyday objects under ecologically valid conditions. Due to an enhanced and multimodal encoding model, superior crystallized abilities might be sufficient to counteract an age-related decline in various other and specific cognitive domains. This approach might potentially elucidate age-related changes in memory performance in both healthy and pathological aging.

Performance of older adults under dual task during stair descent

BackgroundLung cancer patients have low survival rates resulting in over 131,000 deaths in the US in 2021. Muscle health decline from sarcopenia and cachexia increases the risk of death among patients with lung cancer. Though muscle mass is often used for sarcopenia diagnosis and non‐tissue specific weight loss is typically used for cachexia diagnosis, both conditions have no consensus definitions. Therefore, the need for quantitative biomarkers that reflect muscle health changes due to aging and weight loss is critical to mitigate sarcopenia and cachexia. We propose using highly accurate MRI‐based proton density fat fraction (PDFF) as a reference measure of muscle health to develop bedside ultrasound measures as biomarkers of muscle health. We hypothesized that PDFF is associated with ultrasound‐based echointensity (EI) and shear wave elastography (SWE), and that all three modalities are sensitive to muscle health differences between healthy young, healthy older, and older adults undergoing treatment for lung cancer.MethodsWe compared muscle health operationalized as myosteatosis in the mid‐thigh of the rectus femoris using ultrasound‐based brightness‐mode for EI, ultrasound‐based SWE for tissue elasticity, and MRI‐based PDFF for percent fat, which was the reference measure. We compared the 3 measures among young healthy (n=10), older healthy (n=10), and older adults with non‐small cell lung cancer (n=10) in a cross‐sectional pilot study. We also compared non‐myosteatosis measures including subcutaneous adipose tissue thickness and rectus femoris thickness via ultrasound, whole‐leg cross‐sectional area via MRI, and BMI between groups and between myosteatosis measures. We used ANOVAs with Tukey post‐hoc comparisons to assess muscle health between groups and Pearson correlations to determine muscle health measure associations between imaging modalities.ResultsWe found young healthy adults had significantly lower PDFF than older healthy adults and older adults with lung cancer (0.33% vs 2.83% vs 2.93%, respectively; p=0.001). Young adults also had significantly lower EI than older healthy adults, but not older adults with cancer (48.58 vs 81.81 vs 75.35; p=0.008). When comparing between measures, PDFF was highly associated with EI (r=0.62, p&lt;0.001) and moderately inversely associated with SWE (r=‐0.41, p=0.025) but not BMI, rectus femoris thickness, or rectus femoris cross‐sectional area.ConclusionPDFF was sensitive to myosteatosis differences between young and both older adult groups. EI was less sensitive to myosteatosis differences between groups, yet EI was highly associated with PDFF unlike BMI. Our results suggest that the ultrasound measures could serve to determine muscle health at the bedside and are more sensitive to muscle health differences than BMI, which could improve interventions for cachexia and patient outcomes.

We compared the multiplication verification and production performances of healthy younger (n = 20) and older (n = 20) adults to that of mildly demented (Mini Mental Status Exam range: 19–27) individuals diagnosed with probable Alzheimer's disease (n = 18). While healthy older adults and Alzheimer's patients were slower than younger adults, the older adults actually showed significantly smaller problem-size effects for verification and production reaction time (RT) tasks. These results suggest that retrieval of multiplication fact knowledge from long-term memory for multiplicands greater than zero remains largely intact in mildly demented individuals diagnosed with probable Alzheimer's discase, although these individuals may have more difficulty with volitional retrieval because group differences were larger for some production analyses (require volitional retrieval) than for verification analyses (simply requires familiarity). However, for problems involving zero multiplicands (but not 1’s), healthy older adults and especially Alzheimer's patients showed significantly higher error rates than younger adults, suggesting that rule retrieval of correct solutions in memory was impaired in both of these older groups for problems involving zero operands. Also, when RT was regressed on problem size across groups, there was no effect for problem size for the production task for Alzheimer's patients—but there was for healthy younger and older adults. Finally, when verifying problems, there was a significant problem size effect of comparable magnitude for all three groups.

The acute effects of mental fatigue on balance performance in healthy young and older adults – A systematic review and meta-analysis

Lower-limb muscle function in healthy young and older adults across a range of walking speeds

Although anomalous perceptual experiences are common in healthy older adults, they remain poorly characterized. In particular, it is unclear whether the phenomenology of these experiences differs between healthy older and younger adults. The current study examined similarities and differences in the factor structure of the Cardiff Anomalous Perceptions Scale (CAPS) in healthy, community-dwelling older (n = 194; Mage = 71.89, SD = 7.74, range = 52-91; 69.1% female) and younger adults (n = 421, Mage = 19.40, SD = 2.44, range = 17-34; 69.6% female; N = 615), using exploratory and confirmatory factor analysis, together with measurement invariance testing. The results found that a 2-factor correlated model comprising 23 of the original 32 CAPS items provided the best fit to the data. Further, scalar invariance was found between the two samples, indicating equivalence of the factor structure, factor loadings, and thresholds by age group. Compared with younger adults, the latent group means of older adults were also found to be equal on Factor 1, but significantly lower on Factor 2. Evidence of scalar age invariance on the CAPS suggests that this tool is valid for making comparisons between older and younger adults on two dimensions of anomalous perceptual experiences. Further, the results suggest that anomalous perceptions in the general community may be characterized by two components: anomalous body-centered self-experiences (e.g., alterations in body, touch, smell, and taste perception) and anomalous external experiences (e.g., auditory, visual, and sensed presence hallucinations); each of which may have different causes, correlates, and consequences for healthy ageing. (PsycInfo Database Record (c) 2020 APA, all rights reserved).