scholarly journals Age-related deficits of manual grasping in a laboratory versus in an everyday-like setting

2012 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
Otmar Bock ◽  
Fabian Steinberg

This study compared the grasping performance of 24 younger (20-30 years of age) and 24 older subjects (60-70 years of age) in a typical laboratory task (L) where movements were repetitive, externally triggered, purposeless and attention-attracting, and in an everydaylike task (E) where movements were part of a rich behavioral repertoire, internally initiated, purposive and little attended. We registered a wide range of kinematic and force parameters, and calculated their within-subject means and variation coefficients. Multiple differences emerged between the parameter values in L and E. Factor analysis reduced them to five independent effects. We also found multiple differences between the two age groups, with seniors responding more slowly and in a more stereotyped fashion. Multiple significant task x age interactions emerged as well, with age differences being more pronounced in E than in L. The latter finding is of practical relevance, since it suggests that age-related deficits in some real-life situations may be underestimated in laboratory research. It also is of theoretical relevance: it indicates that brain regions which are particularly vulnerable to aging may contribute to task E more than to task L.

1997 ◽  
Vol 82 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Timothy J. Doherty ◽  
William F. Brown

Doherty, Timothy J., and William F. Brown. Age-related changes in the twitch contractile properties of human thenar motor units. J. Appl. Physiol. 82(1): 93–101, 1997.—The purpose of this study was to examine the effects of aging on the contractile and electrophysiological properties of human thenar motor units (MUs). Percutaneous electrical stimulation of single motor axons within the median nerve was used to isolate and examine the twitch tensions, contractile speeds, and surface-detected MU action potential (S-MUAP) sizes of 48 thenar MUs in 17 younger subjects (25–53 yr) and 44 thenar MUs in 9 older subjects (64–77 yr). A wide range of twitch tensions, contractile speeds, and S-MUAP sizes was observed in both age groups. However, older subjects had significantly larger MU twitch tensions and slower MU twitch contraction and half-relaxation times. These changes were accompanied by increased S-MUAP sizes. These findings suggest that the human thenar MU pool undergoes significant age-related increase in MU size and slowing of contractile speed. Such adaptation may help to overcome previously reported age-related losses of thenar MUs.


2014 ◽  
Vol 30 (4) ◽  
pp. 542-546 ◽  
Author(s):  
Dennis E. Anderson ◽  
Christopher T. Franck ◽  
Michael L. Madigan

The effects of gait speed and step length on the required coefficient of friction (COF) confound the investigation of age-related differences in required COF. The goals of this study were to investigate whether age differences in required COF during self-selected gait persist when experimentally-controlling speed and step length, and to determine the independent effects of speed and step length on required COF. Ten young and 10 older healthy adults performed gait trials under five gait conditions: self-selected, slow and fast speeds without controlling step length, and slow and fast speeds while controlling step length. During self-selected gait, older adults walked with shorter step lengths and exhibited a lower required COF. Older adults also exhibited a lower required COF when walking at a controlled speed without controlling step length. When both age groups walked with the same speed and step length, no age difference in required COF was found. Thus, speed and step length can have a large influence on studies investigating age-related differences in required COF. It was also found that speed and step length have independent and opposite effects on required COF, with step length having a strong positive effect on required COF, and speed having a weaker negative effect.


2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Karen P. Y. Liu ◽  
Monica Lai ◽  
Shirley S. M. Fong ◽  
Michelle Bissett

This study examined if imagery ability (i.e., vividness and temporal congruence between imagined and executed knee extensions) and imagery perspective preference were affected by ageing and gender. Ninety-four participants, 31 young, 43 intermediate, and 20 older adults completed the Vividness of Movement Imagery Questionnaire-2 and a knee extension temporal congruence test to reflect on their imagery ability and an imagery perspective preference test. Male participants had a better imagery ability than the female participants (F 4,85=2.84, p=.029, η2=.118). However, significant age-related changes in imagery ability were not found in the three age groups. Change in imagery perspective preference with a trend towards an external imagery perspective was observed with ageing (F 3,89=3.16, p=.028, η2=.096) but not between male and female. The results suggest that imagery ability may be preserved with ageing. As individuals age, their preference for using an imagery perspective shifts from a more internal to a more external perspective. This understanding is important when designing future imagery research and real-life application or clinical intervention.


Author(s):  
Lauren Werner ◽  
Gaojian Huang ◽  
Brandon J. Pitts

The number of older adults is growing significantly worldwide. At the same time, technological developments are rapidly evolving, and older populations are expected to interact more frequently with such sophisticated systems. Automated speech recognition (ASR) systems is an example of one technology that is increasingly present in daily life. However, age-related physical changes may alter speech production and limit the effectiveness of ASR systems for older individuals. The goal of this paper was to summarize the current knowledge on ASR systems and older adults. The PRISMA method was employed and 17 studies were compared on the basis of word error rate (WER). Overall, WER was found to be influenced by age, gender, and the number of speech samples used to train ASR systems. This work has implications for the development of future human-machine technologies that will be used by a wide range of age groups.


2004 ◽  
Vol 16 (8) ◽  
pp. 1339-1351 ◽  
Author(s):  
Kathleen M. Thomas ◽  
Ruskin H. Hunt ◽  
Nathalie Vizueta ◽  
Tobias Sommer ◽  
Sarah Durston ◽  
...  

Prevailing theories of implicit or unaware learning propose a developmental invariance model, with implicit function maturing early in infancy or childhood despite prolonged improvements in explicit or intentional learning and memory systems across childhood. Neuroimaging studies of adult visuomotor sequence learning have associated fronto-striatal brain regions with implicit learning of spatial sequences. Given evidence of continued development in these brain regions during childhood, we compare implicit sequence learning in adults and 7- to 11-year-old children to examine potential developmental differences in the recruitment of fronto-striatal circuitry during implicit learning. Participants performed a standard serial reaction time task. Stimuli alternately followed a fixed 10-step sequence of locations or were presented in a pseudorandom order of locations. Adults outperformed children, achieving a significantly larger sequence learning effect and showing learning more quickly than children. Age-related differences in activity were observed in the premotor cortex, putamen, hippocampus, inferotemporal cortex, and parietal cortex. We observed differential recruitment of cortical and subcortical motor systems between groups, presumably reflecting age differences in motor response execution. Adults showed greater hippocampal activity for sequence trials, whereas children demonstrated greater signal during random trials. Activity in the right caudate correlated significantly with behavioral measures of implicit learning for both age groups, although adults showed greater signal change than children overall, as would be expected given developmental differences in sequence learning magnitude. These results challenge the idea of developmental invariance in implicit learning and instead support a view of parallel developments in implicit and explicit learning systems.


1987 ◽  
Vol 10 (3) ◽  
pp. 359-375 ◽  
Author(s):  
Michael W. Pratt ◽  
Gail Golding ◽  
Patricia Kerig

Recent work on aging and moral judgment has investigated the claim that older adults may show a regression in their average stage level of moral judgment, compared with younger groups. A second line of work has suggested that at least some elderly adults may be more reflective in their thinking regarding moral and ethical issues (e.g. Kohlberg, 1973). The present research was designed to investigate these issues with respect to hypothetical and real-life moral judgment. Subjects were 60 adults in three age groups: 18-24 years, 30-45 years, and 60-75 years. Each responded to the Kohlberg Moral Judgment Interview and to the personal moral dilemma task of Gilligan. Measures of stage level and of reported use of perspectivetaking processes, as well as analyses of the content of personal dilemmas, were obtained. Results showed no average stage level differences between the age or sex groups. Hypothetical stage scores were significantly higher than real-life scores overall. There were no age differences in reported role-taking processes on hypothetical dilemmas, though there were sex differences, with men more likely to report adopting a third-party, observer role. Finally, older subjects produced significantly more varied reflections on their personal dilemmas.


2007 ◽  
Vol 19 (3) ◽  
pp. 319-333 ◽  
Author(s):  
Khalid S. Almuzaini

The main purpose of the present study was to determine isokinetic strength and endurance, isometric strength, and anaerobic power for untrained healthy Saudi children and adolescents. The secondary purpose was to evaluate the effects of age in relation to anthropometric characteristics on strength and anaerobic performances. Forty-four (untrained) 11- to 19-year-old boys were grouped by age: 11-13 years, 14–16 years, and 17–19 years. All participants underwent anthropometric measurements, a flexibility test, a vertical jump test, a grip strength test, isokinetic strength measurements (Cybex Norm), and a Wingate anaerobic power test. Oneway ANOVA results indicated age-related increases in muscle strength and power. High correlation coefficients that were found among age and strength and anaerobic power indices almost disappeared when fat-free mass (FFM) was controlled for, indicating that the amount of variance in these indices that was explained by age is mostly shared by FFM. In addition, stepwise linear regression models indicated that FFM was the main predictor of strength and power performances. Thus, FFM was the best scaling variable for body size when comparing these age groups of Saudis. Until wide-range normal representative values for isokinetic strength and anaerobic power for Saudi children and adolescents are available, the present study’s results can serve as a reference for these indices.


2020 ◽  
Author(s):  
Nils Rosjat ◽  
Bin A. Wang ◽  
Liqing Liu ◽  
Gereon R. Fink ◽  
Silvia Daun

AbstractCognitive performance slows down with increasing age. This includes cognitive processes that are essential for the performance of a motor act, such as the slowing down in response to an external stimulus. The objective of this study was to identify aging-associated functional changes in the brain networks that are involved in the transformation of external stimuli into motor action. To investigate this topic, we employed dynamic graphs based on phase-locking of Electroencephalography signals recorded from healthy younger and older subjects while performing a simple visually-cued finger-tapping task. The network analysis yielded specific age-related network structures varying in time in the low frequencies (2-7 Hz), which are closely connected to stimulus processing, movement initiation and execution in both age groups. The networks in older subjects, however, contained several additional, particularly interhemispheric, connections and showed an overall increased coupling density. Cluster analyses revealed reduced variability of the subnetworks in older subjects, particularly during movement preparation. In younger subjects, occipital, parietal, sensorimotor and central regions were - temporally arranged in this order - heavily involved in hub nodes. Whereas in older subjects, a hub in frontal regions preceded the noticeably delayed occurrence of sensorimotor hubs, indicating different neural information processing in older subjects.All observed changes in brain network organization, which are based on neural synchronization in the low frequencies, provide a possible neural mechanism underlying previous fMRI data, which report an overactivation, especially in the prefrontal and pre-motor areas, associated with a loss of hemispheric lateralization in older subjects.


2021 ◽  
Vol 12 ◽  
Author(s):  
Esther C. McWilliams ◽  
Florentine M. Barbey ◽  
John F. Dyer ◽  
Md Nurul Islam ◽  
Bernadette McGuinness ◽  
...  

Access to affordable, objective and scalable biomarkers of brain function is needed to transform the healthcare burden of neuropsychiatric and neurodegenerative disease. Electroencephalography (EEG) recordings, both resting and in combination with targeted cognitive tasks, have demonstrated utility in tracking disease state and therapy response in a range of conditions from schizophrenia to Alzheimer's disease. But conventional methods of recording this data involve burdensome clinic visits, and behavioural tasks that are not effective in frequent repeated use. This paper aims to evaluate the technical and human-factors feasibility of gathering large-scale EEG using novel technology in the home environment with healthy adult users. In a large field study, 89 healthy adults aged 40–79 years volunteered to use the system at home for 12 weeks, 5 times/week, for 30 min/session. A 16-channel, dry-sensor, portable wireless headset recorded EEG while users played gamified cognitive and passive tasks through a tablet application, including tests of decision making, executive function and memory. Data was uploaded to cloud servers and remotely monitored via web-based dashboards. Seventy-eight participants completed the study, and high levels of adherence were maintained throughout across all age groups, with mean compliance over the 12-week period of 82% (4.1 sessions per week). Reported ease of use was also high with mean System Usability Scale scores of 78.7. Behavioural response measures (reaction time and accuracy) and EEG components elicited by gamified stimuli (P300, ERN, Pe and changes in power spectral density) were extracted from the data collected in home, across a wide range of ages, including older adult participants. Findings replicated well-known patterns of age-related change and demonstrated the feasibility of using low-burden, large-scale, longitudinal EEG measurement in community-based cohorts. This technology enables clinically relevant data to be recorded outside the lab/clinic, from which metrics underlying cognitive ageing could be extracted, opening the door to potential new ways of developing digital cognitive biomarkers for disorders affecting the brain.


2020 ◽  
Vol 245 (17) ◽  
pp. 1584-1593 ◽  
Author(s):  
Pichet Termsarasab ◽  
Thananan Thammongkolchai ◽  
Ju Gao ◽  
Luwen Wang ◽  
Jingjing Liang ◽  
...  

Transactive response DNA binding protein 43 (TDP-43) pathologies have been well recognized in various neurodegenerative disorders including frontotemporal lobar degeneration (FTLD), amyotrophic lateral sclerosis (ALS), and Alzheimer’s disease (AD). However, there have been limited studies on whether there are any TDP-43 alterations in normal aging. We investigated TDP-43 distribution in different brain regions in normal aged ( n =  3 for 26- or 36-month-old) compared to young ( n =  3 for 6- or 12-month-old) mice. In both normal aged and young mice, TDP-43 and phosphorylated TDP-43 (pTDP-43) demonstrated a unique pattern of distribution in neurons in some specific brain regions including the pontine nuclei, thalamus, CA3 region of the hippocampus, and orbital cortex. This pattern was demonstrated on higher magnification of high-resolution double fluorescence images and confocal microscopy as mislocalization of TDP-43 and pTDP-43, characterized by neuronal nuclear depletion and cytoplasmic accumulation in these brain regions, as well as colocalization between TDP-43 or pTDP-43 and mitochondria, similar to what has been described previously in neurodegenerative disorders. All these findings were identical in both normal aged and young mice. In summary, TDP-43 and pTDP-43 mislocalization from nucleus to cytoplasm and their colocalization with mitochondria in the specific brain regions are present not only in aging, but also in young healthy states. Our findings provide a new insight for the role of TDP-43 proteinopathy in health and diseases, and that aging may not be a critical factor for the development of TDP-43 proteinopathy in subpopulations of neurons. Impact statement Despite increasing evidence implicating the important role of TDP-43 in the pathogenesis of a wide range of age-related neurodegenerative diseases, there is limited study of TDP-43 proteinopathy and its association with mitochondria during normal aging. Our findings of cytoplasmic accumulation of TDP-43 that is highly colocalized with mitochondria in neurons in selective brain regions in young animals in the absence of neuronal loss provide a novel insight into the development of TDP-43 proteinopathy and its contribution to neuronal loss.


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