scholarly journals Gravity effects are better optimized by older than young adults when reaching with the non-dominant arm

2021 ◽  
Author(s):  
Gabriel Poirier ◽  
Charalambos Papaxanthis ◽  
Adrien Juranville ◽  
Mélanie Lebigre ◽  
France Mourey ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Motor Control ◽  
Control Process ◽  
Open Loop ◽  
Emg Activity ◽  
Aging Effects ◽  
Arm Kinematics ◽  
Age Related ◽  
Gravity Effects

Motor lateralization refers to differences in the neural organization of cerebral hemispheres, resulting in different control specializations between the dominant and the non-dominant motor systems. Multiple studies proposed that the dominant hemisphere is specialized for open-loop optimization-like processes. Recently, comparing arm kinematics between upward and downward movements, we found that the dominant arm outperformed the non-dominant one regarding gravity-related motor optimization in healthy young subjects. The literature about aging effects on motor control presents several neurophysiological and behavioral evidences for an age-related reduction of motor lateralization. Here, we compare the lateralization of a well-known gravity-related optimal motor control process between young and older adults. Thirty healthy young (mean age = 24.1 ± 3 years) and nineteen healthy older adults (mean age = 73.0 ± 8) performed single degree-of-freedom vertical arm movements between two targets (upward and downward). Participants alternatively reached with their dominant and non-dominant arms. We recorded arm kinematics and electromyographic activities of the prime movers (Anterior and Posterior Deltoids) and we analyzed parameters thought to represent the hallmark of the gravity-related optimization process (i.e directional asymmetries and negative epochs on the phasic EMG activity). We found no arm difference in older participants, such that parameters with both arms were similar to those of young participants with their dominant arm. With the non-dominant arm, these results suggest that older adults better optimize gravity effects than young adults.

scholarly journals Reduced corticospinal responses in older compared with younger adults during submaximal isometric, shortening, and lengthening contractions

2019 ◽  
Vol 126 (4) ◽  
pp. 1015-1031 ◽  
Author(s):  
Jakob Škarabot ◽  
Paul Ansdell ◽  
Callum G. Brownstein ◽  
Kirsty M. Hicks ◽  
Glyn Howatson ◽  
...  
Keyword(s):  
Older Adults ◽  
Motor Control ◽  
Motor Evoked Potentials ◽  
Production Capacity ◽  
Emg Activity ◽  
Younger Adults ◽  
Lengthening Contractions ◽  
Age Related ◽  
Age Dependent ◽  
Contraction Type

The aim of this study was to assess differences in motor performance, as well as corticospinal and spinal responses to transcranial magnetic and percutaneous nerve stimulation, respectively, during submaximal isometric, shortening, and lengthening contractions between younger and older adults. Fifteen younger [26 yr (SD 4); 7 women, 8 men] and 14 older [64 yr (SD 3); 5 women, 9 men] adults performed isometric and shortening and lengthening dorsiflexion on an isokinetic dynamometer (5°/s) at 25% and 50% of contraction type-specific maximums. Motor evoked potentials (MEPs) and H reflexes were recorded at anatomical zero. Maximal dorsiflexor torque was greater during lengthening compared with shortening and isometric contractions ( P < 0.001) but was not age dependent ( P = 0.158). However, torque variability was greater in older compared with young adults ( P < 0.001). Background electromyographic (EMG) activity was greater in older compared with younger adults ( P < 0.005) and was contraction type dependent ( P < 0.001). As evoked responses are influenced by both the maximal level of excitation and background EMG activity, the responses were additionally normalized {[MEP/maximum M wave (Mmax)]/root-mean-square EMG activity (RMS) and [H reflex (H)/Mmax]/RMS}. (MEP/Mmax)/RMS and (H/Mmax)/RMS were similar across contraction types but were greater in young compared with older adults ( P < 0.001). Peripheral motor conduction times were prolonged in older adults ( P = 0.003), whereas peripheral sensory conduction times and central motor conduction times were not age dependent ( P ≥ 0.356). These data suggest that age-related changes throughout the central nervous system serve to accommodate contraction type-specific motor control. Moreover, a reduction in corticospinal responses and increased torque variability seem to occur without a significant reduction in maximal torque-producing capacity during older age. NEW & NOTEWORTHY This is the first study to have explored corticospinal and spinal responses with aging during submaximal contractions of different types (isometric, shortening, and lengthening) in lower limb musculature. It is demonstrated that despite preserved maximal torque production capacity corticospinal responses are reduced in older compared with younger adults across contraction types along with increased torque variability during dynamic contractions. This suggests that the age-related corticospinal changes serve to accommodate contraction type-specific motor control.

scholarly journals Age-related changes in the neuromuscular control of forward and backward locomotion

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246372
Author(s):  
Arthur H. Dewolf ◽  
Francesca Sylos-Labini ◽  
Germana Cappellini ◽  
Yury Ivanenko ◽  
Francesco Lacquaniti
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Neuromuscular Control ◽  
Emg Activity ◽  
Intersegmental Coordination ◽  
Backward Walking ◽  
Lower Limb Muscles ◽  
Age Related ◽  
Spatiotemporal Parameters ◽  
Age Related Changes

Previous studies found significant modification in spatiotemporal parameters of backward walking in healthy older adults, but the age-related changes in the neuromuscular control have been considered to a lesser extent. The present study compared the intersegmental coordination, muscle activity and corresponding modifications of spinal montoneuronal output during both forward and backward walking in young and older adults. Ten older and ten young adults walked forward and backward on a treadmill at different speeds. Gait kinematics and EMG activity of 14 unilateral lower-limb muscles were recorded. As compared to young adults, the older ones used shorter steps, a more in-phase shank and foot motion, and the activity profiles of muscles innervated from the sacral segments were significantly wider in each walking condition. These findings highlight age-related changes in the neuromuscular control of both forward and backward walking. A striking feature of backward walking was the differential organization of the spinal output as compared to forward gait. In addition, the resulting spatiotemporal map patterns also characterized age-related changes of gait. Finally, modifications of the intersegmental coordination with aging were greater during backward walking. On the whole, the assessment of backward walk in addition to routine forward walk may help identifying or unmasking neuromuscular adjustments of gait to aging.

Inefficient Encoding as an Explanation for Age-Related Deficits in Recollection-Based Processing

2014 ◽  
Vol 28 (3) ◽  
pp. 148-161 ◽  
Author(s):  
David Friedman ◽  
Ray Johnson
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Cognitive Processes ◽  
Brain Activity ◽  
Memory Performance ◽  
Brain Regions ◽  
Semantic Retrieval ◽  
Age Related ◽  
The Face ◽  
Episodic Memories

A cardinal feature of aging is a decline in episodic memory (EM). Nevertheless, there is evidence that some older adults may be able to “compensate” for failures in recollection-based processing by recruiting brain regions and cognitive processes not normally recruited by the young. We review the evidence suggesting that age-related declines in EM performance and recollection-related brain activity (left-parietal EM effect; LPEM) are due to altered processing at encoding. We describe results from our laboratory on differences in encoding- and retrieval-related activity between young and older adults. We then show that, relative to the young, in older adults brain activity at encoding is reduced over a brain region believed to be crucial for successful semantic elaboration in a 400–1,400-ms interval (left inferior prefrontal cortex, LIPFC; Johnson, Nessler, & Friedman, 2013 ; Nessler, Friedman, Johnson, & Bersick, 2007 ; Nessler, Johnson, Bersick, & Friedman, 2006 ). This reduced brain activity is associated with diminished subsequent recognition-memory performance and the LPEM at retrieval. We provide evidence for this premise by demonstrating that disrupting encoding-related processes during this 400–1,400-ms interval in young adults affords causal support for the hypothesis that the reduction over LIPFC during encoding produces the hallmarks of an age-related EM deficit: normal semantic retrieval at encoding, reduced subsequent episodic recognition accuracy, free recall, and the LPEM. Finally, we show that the reduced LPEM in young adults is associated with “additional” brain activity over similar brain areas as those activated when older adults show deficient retrieval. Hence, rather than supporting the compensation hypothesis, these data are more consistent with the scaffolding hypothesis, in which the recruitment of additional cognitive processes is an adaptive response across the life span in the face of momentary increases in task demand due to poorly-encoded episodic memories.

scholarly journals Strategies and cognitive reserve to preserve lexical production in aging

GeroScience ◽  
2021 ◽  
Author(s):  
Monica Baciu ◽  
Sonja Banjac ◽  
Elise Roger ◽  
Célise Haldin ◽  
Marcela Perrone-Bertolotti ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Aging ◽  
Individual Variability ◽  
Future Research ◽  
Aging Effects ◽  
Main Hypothesis ◽  
Compensatory Strategies ◽  
Age Related ◽  
Complementary Domain

AbstractIn the absence of any neuropsychiatric condition, older adults may show declining performance in several cognitive processes and among them, in retrieving and producing words, reflected in slower responses and even reduced accuracy compared to younger adults. To overcome this difficulty, healthy older adults implement compensatory strategies, which are the focus of this paper. We provide a review of mainstream findings on deficient mechanisms and possible neurocognitive strategies used by older adults to overcome the deleterious effects of age on lexical production. Moreover, we present findings on genetic and lifestyle factors that might either be protective or risk factors of cognitive impairment in advanced age. We propose that “aging-modulating factors” (AMF) can be modified, offering prevention opportunities against aging effects. Based on our review and this proposition, we introduce an integrative neurocognitive model of mechanisms and compensatory strategies for lexical production in older adults (entitled Lexical Access and Retrieval in Aging, LARA). The main hypothesis defended in LARA is that cognitive aging evolves heterogeneously and involves complementary domain-general and domain-specific mechanisms, with substantial inter-individual variability, reflected at behavioral, cognitive, and brain levels. Furthermore, we argue that the ability to compensate for the effect of cognitive aging depends on the amount of reserve specific to each individual which is, in turn, modulated by the AMF. Our conclusion is that a variety of mechanisms and compensatory strategies coexist in the same individual to oppose the effect of age. The role of reserve is pivotal for a successful coping with age-related changes and future research should continue to explore the modulating role of AMF.

Mechanism of Sequential Swallowing During Straw Drinking in Healthy Young and Older Adults

2004 ◽  
Vol 47 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Stephanie K. Daniels ◽  
David M. Corey ◽  
Leslie D. Hadskey ◽  
Calli Legendre ◽  
Daniel H. Priestly ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Movement Patterns ◽  
Leading Edge ◽  
Normal Aging ◽  
Significant Relation ◽  
Age Related ◽  
Laryngeal Penetration ◽  
Airway Invasion ◽  
Edge Location

Recent research has revealed differences between isolated and sequential swallowing in healthy young adults; however, the influence of normal aging on sequential swallowing has not been studied. Thus, the purpose of this investigation was to examine the effects of normal aging on deglutition during sequential straw drinking. Videofluoroscopic samples of two 10-s straw drinking trials were obtained for 20 healthy young men (age 29±3 years) and 18 healthy older men (age 69±7 years). Hyolaryngeal complex (HLC) movement patterns, leading edge of the bolus location at swallow onset, and occurrences of airway invasion were determined. Two HLC patterns were identified: (a) HLC lowering with the epiglottis returned to upright between swallows and (b) partially maintained HLC elevation with the epiglottis inverted between swallows. The bolus was frequently in the hypopharynx at swallow onset. Strong associations were identified between age and HLC pattern, age and leading edge of the bolus location, and HLC pattern and leading edge location. Laryngeal penetration was uncommon overall; however, it occurred more frequently in the older adults than in the young adults. A significant relation was identified between age and the average Penetration-Aspiration Scale score. Laryngeal penetration was associated with both HLC movement patterns and hypopharyngeal bolus location, particularly in older adults. Results indicate that subtle age-related differences are evident in healthy young and older adults with sequential straw drinking. These data suggest that specific inherent swallowing patterns may increase the risk of laryngeal penetration with normal aging.

Processing gender stereotypes in dementia patients and older healthy adults: a self-paced reading study

2019 ◽  
Vol 5 (s2) ◽  
Author(s):  
Daniel Müller-Feldmeth ◽  
Katharina Ahnefeld ◽  
Adriana Hanulíková
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Sentence Processing ◽  
Gender Stereotypes ◽  
Time Course ◽  
Healthy Adults ◽  
Control Group ◽  
Healthy Older Adults ◽  
Dementia Patients ◽  
Age Related

AbstractWe used self-paced reading to examine whether stereotypical associations of verbs with women or men as prototypical agents (e.g. the craftsman knits a sweater) are activated during sentence processing in dementia patients and healthy older adults. Effects of stereotypical knowledge on language processing have frequently been observed in young adults, but little is known about age-related changes in the activation and integration of stereotypical information. While syntactic processing may remain intact, semantic capacities are often affected in dementia. Since inferences based on gender stereotypes draw on social and world knowledge, access to stereotype information may also be affected in dementia patients. Results from dementia patients (n = 9, average age 86.6) and healthy older adults (n = 14, average age 79.5) showed slower reading times and less accuracy in comprehension scores for dementia patients compared to the control group. While activation of stereotypical associations of verbs was visible in both groups, they differed with respect to the time-course of processing. The effect of stereotypes on comprehension accuracy was visible for healthy adults only. The evidence from reading times suggests that older adults with and without dementia engage stereotypical inferences during reading, which is in line with research on young adults.

scholarly journals Systematic review and meta-analysis of age-related differences in instructed emotion regulation success

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6051 ◽  
Author(s):  
Brooke Brady ◽  
Ian I. Kneebone ◽  
Nida Denson ◽  
Phoebe E. Bailey
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Emotion Regulation ◽  
Process Model ◽  
Meta Analysis ◽  
Cognitive Change ◽  
Emotional Behavior ◽  
Response Modulation ◽  
Age Related ◽  
Process Strategy

The process model of emotion regulation (ER) is based on stages in the emotion generative process at which regulation may occur. This meta-analysis examines age-related differences in the subjective, behavioral, and physiological outcomes of instructed ER strategies that may be initiated after an emotional event has occurred; attentional deployment, cognitive change, and response modulation. Within-process strategy, stimulus type, and valence were also tested as potential moderators of the effect of age on ER. A systematic search of the literature identified 156 relevant comparisons from 11 studies. Few age-related differences were found. In our analysis of the subjective outcome of response modulation strategies, young adults used expressive enhancement successfully (g = 0.48), but not expressive suppression (g = 0.04). Response modulation strategies had a small positive effect among older adults, and enhancement vs suppression did not moderate this success (g = 0.31 and g = 0.10, respectively). Young adults effectively used response modulation to regulate subjective emotion in response to pictures (g = 0.41) but not films (g = 0.01). Older adults were able to regulate in response to both pictures (g = 0.26) and films (g = 0.11). Interestingly, both age groups effectively used detached reappraisal, but not positive reappraisal to regulate emotional behavior. We conclude that, in line with well-established theories of socioemotional aging, there is a lack of evidence for age differences in the effects of instructed ER strategies, with some moderators suggesting more consistent effectiveness for older compared to younger adults.

scholarly journals Electrophysiological Evidence for Preserved Primacy of Lexical Prediction in Normative Aging

2017 ◽  
Author(s):  
Shruti Dave ◽  
Trevor A. Brothers ◽  
Matthew J. Traxler ◽  
Fernanda Ferreira ◽  
John M. Henderson ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Prediction Accuracy ◽  
Predictive Accuracy ◽  
Accurate Prediction ◽  
Self Report ◽  
Clear Cut ◽  
Age Related ◽  
Contextual Support ◽  
Normative Aging

Young adults show consistent neural benefits of predictable contexts when processing upcoming words, but these benefits are less clear-cut in older adults. Here we conduct two ERP experiments to examine whether aging uniquely affects neural correlates of prediction accuracy, as compared to contextual support independent of accuracy. In Experiment 1, readers were asked to predict sentence-final words and self-report prediction accuracy, allowing for separation of ERP effects of accurate prediction and contextual support. While N250 and N400 effects of accurate prediction were reduced in older readers, both temporal primacy and relative amplitudes of predictive compared to contextual processing were similar across age. In Experiment 2, participants read for comprehension without an overt prediction task and showed similar age-related declines in N400 amplitude across experiments. In both studies, older adults showed relatively larger frontal post-N400 positivities (PNPs) than young adults, suggesting age-graded differences in revision following unexpected items. Previous research suggests the production system may be linked to lexical prediction, but here we found that verbal fluency modulated PNP effects of contextual support, but not predictive accuracy. Taken together, our findings suggest that normative aging does not result in specific declines or boosts of lexical prediction.

scholarly journals Directed connectivity between primary and premotor areas underlying ankle force control in young and older adults

2019 ◽  
Author(s):  
Meaghan Elizabeth Spedden ◽  
Mikkel Malling Beck ◽  
Mark Schram Christensen ◽  
Martin Jensen Dietz ◽  
Anke Ninija Karabanov ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Force Control ◽  
Coupling Strength ◽  
Empirical Bayes ◽  
Premotor Cortex ◽  
Force Production ◽  
Age Group ◽  
Compensatory Mechanisms ◽  
Age Related

AbstractThe control of ankle muscle force is an integral component of walking and postural control. Aging impairs the ability to produce force steadily and accurately, which can compromise functional capacity and quality of life. Here, we hypothesized that reduced force control in older adults would be associated with altered cortico-cortical communication within a network comprising the primary motor area (M1), the premotor cortex (PMC), parietal, and prefrontal regions. We examined electroencephalographic (EEG) responses from fifteen younger (20-26 yr) and fifteen older (65-73 yr) participants during a unilateral dorsiflexion force-tracing task. Dynamic Causal Modelling (DCM) and Parametric Empirical Bayes (PEB) were used to investigate how directed connectivity between contralateral M1, PMC, parietal, and prefrontal regions was related to age group and precision in force production. DCM and PEB analyses revealed that the strength of connections between PMC and M1 were related to ankle force precision and differed by age group. For young adults, bidirectional PMC-M1 coupling was negatively related to task performance: stronger backward M1-PMC and forward PMC-M1 coupling was associated with worse force precision. The older group exhibited deviations from this pattern. For the PMC to M1 coupling, there were no age-group differences in coupling strength; however, within the older group, stronger coupling was associated with better performance. For the M1 to PMC coupling, older adults followed the same pattern as young adults - with stronger coupling accompanied by worse performance - but coupling strength was lower than in the young group. Our results suggest that bidirectional M1-PMC communication is related to precision in ankle force production and that this relationship changes with aging. We argue that the observed age-related differences reflect compensatory mechanisms whereby older adults maintain performance in the face of declines in the sensorimotor system.

Kinematic Analysis of Dance-Based Exergaming: A Cross-Sectional Study

2021 ◽  
Author(s):  
Ernest K. Ofori ◽  
Savitha Subramaniam ◽  
Shuaijie Wang ◽  
Tanvi Bhatt
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Postural Stability ◽  
Center Of Mass ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Healthy Older Adults ◽  
Age Related ◽  
Aging Populations ◽  
Cortical Pathology

Background: Recent studies demonstrate improvements in both postural stability and mobility among aging populations and those with stroke who are exposed to dance-based exergaming (DBExG). However, age-related deficits and aging with cortical pathology may lead to distinct movement adaptation patterns during DBExG, which could impact therapeutic outcomes.Aim: The aim of this study was to examine the movement kinematics (postural stability and mobility) of healthy older adults, older adults with stroke, and young adults for different paces of dance during DBExG. Method: The study included 33 particpants (11 participant from each group of healthy older adults, older adults with chronic stroke, and healthy young adults) who performed the DBExG using slow- (SP), medium- (MP), and fast-paced (FP) songs with movements in the anteroposterior (AP) and mediolateral (ML) directions. Center of mass (CoM) sway area, excursion (Ex), and peaks as well as hip, knee, and ankle joint excursions were computed. Results: Results of the study revealed that CoM sway areas and Exs were greater for healthy young adults than for older adults with stroke for the SP dance (p < 0.05) and that there were significantly more AP CoM peaks for young adults than for healthy older adults and those with stroke for the FP dance (p < 0.05). Young adults also exhibited greater hip and ankle Exs than older adults with stroke (p < 0.05) for all song paces. Similarly, knee and ankle Exs were greater for healthy older adults than for older adults with stroke for all song paces (p < 0.05). Conclusion: The quantitative evaluation and comparison of the movement patterns presented for the three groups could provide a foundation for both assessing and designing therapeutic DBExG protocols for these populations.

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