scholarly journals Role of motor skills and visual demand for age-related deficits in dual-task walking

2011 ◽  
Vol 2 (1) ◽  
pp. 5 ◽  
Author(s):  
Rainer Beurskens ◽  
Otmar Bock
Keyword(s):  
Dual Task ◽  
Visual Processing ◽  
Elderly Subjects ◽  
Similar Degree ◽  
Verbal Responses ◽  
Age Related ◽  
Manual Skills ◽  
Young Subjects ◽  
Task Conditions

Previous studies suggested that age-related deficits of walking are accentuated under dual-task conditions when the non-walking task is visually demanding. Here we evaluate whether a requirement for manual skills is critical as well. Young (22±2 years) and older (69±3 years) subjects walked along a straight path while performing a task that required manual skills but no visual processing, i.e., checking off boxes on a handheld panel without seeing the arm, or a task that required visual processing but no manual skill , i.e., a Stroop-like task with verbal responses. We found that the checking task affected the performance of young and elderly subjects to a similar degree, while the Stroop-like task affected seniors’ performance more than that of young subjects. This outcome confirms the role of visual demand for age-related deficits of dual-task walking (in the Stroop-like task), but doesn’t support a similar role for manual skills (in the checking task).

scholarly journals Effects of a Visual Distracter Task on the Gait of Elderly versus Young Persons

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Otmar Bock ◽  
Rainer Beurskens
Keyword(s):  
Executive Functions ◽  
Everyday Life ◽  
Mental Rotation ◽  
Dual Task ◽  
Visual Processing ◽  
The Elderly ◽  
Spatiotemporal Variability ◽  
Elderly Subjects ◽  
Visual Distracter ◽  
Young Subjects

Seniors show deficits of dual-task walking when the second task has high visual-processing requirements. Here, we evaluate whether similar deficits emerge when the second task is discrete rather than continuous, as is often the case in everyday life. Subjects walked in a hallway, while foot proprioception was either perturbed by vibration or unperturbed. At unpredictable intervals, they were prompted to turn their head and perform a mental-rotation task. We found that locomotion of young subjects was not affected by this distracter task with or without vibration. In contrast, seniors moved their legs after the distraction at a slower pace through smaller angles and with a higher spatiotemporal variability; the magnitude of these changes was vibration independent. We conclude that the visual distracter task degraded the gait of elderly subjects but completely spared young ones, that this effect is not due to degraded proprioception, and that it rather might reflect the known decline of executive functions in the elderly.

scholarly journals Extra Virgin Olive Oil Prevents the Age-Related Shifts of the Distribution of HDL Subclasses and Improves Their Functionality

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2235
Author(s):  
Alyann Otrante ◽  
Amal Trigui ◽  
Roua Walha ◽  
Hicham Berrougui ◽  
Tamas Fulop ◽  
...  
Keyword(s):  
Olive Oil ◽  
Virgin Olive Oil ◽  
Density Lipoprotein ◽  
Extra Virgin Olive Oil ◽  
The Elderly ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
Elderly Subjects ◽  
Age Related ◽  
Young Subjects

High-density lipoproteins (HDL) maintain cholesterol homeostasis through the role they play in regulating reverse cholesterol transport (RCT), a process by which excess cholesterol is transported back to the liver for elimination. However, RCT can be altered in the presence of cardiovascular risk factors, such as aging, which contributes to the increase in the incidence of cardiovascular diseases (CVD). The present study was aimed at investigating the effect of extra virgin olive oil (EVOO) intake on the cholesterol efflux capacity (CEC) of HDL, and to elucidate on the mechanisms by which EVOO intake improves the anti-atherogenic activity of HDL. A total of 84 healthy women and men were enrolled and were distributed, according to age, into two groups: 27 young (31.81 ± 6.79 years) and 57 elderly (70.72 ± 5.6 years) subjects. The subjects in both groups were given 25 mL/d of extra virgin olive oil (EVOO) for 12 weeks. CEC was measured using J774 macrophages radiolabeled with tritiated cholesterol ((3H) cholesterol). HDL subclass distributions were analyzed using the Quantimetrix Lipoprint® system. The HDL from the elderly subjects exhibited a lower level of CEC, at 11.12% (p < 0.0001), than the HDL from the young subjects. The CEC of the elderly subjects returned to normal levels following 12 weeks of EVOO intake. An analysis of the distribution of HDL subclasses showed that HDL from the elderly subjects were composed of lower levels of large HDL (L-HDL) (p < 0.03) and higher levels of small HDL (S-HDL) (p < 0.002) compared to HDL from the young subjects. A multiple linear regression analysis revealed a positive correlation between CEC and L-HDL levels (r = 0.35 and p < 0.001) as well as an inverse correlation between CEC and S-HDL levels (r = −0.27 and p < 0.01). This correlation remained significant even when several variables, including age, sex, and BMI as well as low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and glucose levels (β = 0.28, p < 0.002, and β = 0.24, p = 0.01) were accounted for. Consuming EVOO for 12 weeks modulated the age-related difference in the distribution of HDL subclasses by reducing the level of S-HDL and increasing the level of intermediate-HDL/large-HDL (I-HDL/L-HDL) in the elderly subjects. The age-related alteration of the CEC of HDL was due, in part, to an alteration in the distribution of HDL subclasses. A diet enriched in EVOO improved the functionality of HDL through an increase in I-HDL/L-HDL and a decrease in S-HDL.

Decreased Neutrophil Cyclic AMP Response to Isoprenaline Stimulation in the Elderly

1983 ◽  
Vol 65 (2) ◽  
pp. 155-157 ◽  
Author(s):  
T. G. Cotter ◽  
K. O'Malley
Keyword(s):  
Monoclonal Antibodies ◽  
Cyclic Amp ◽  
The Elderly ◽  
Population Heterogeneity ◽  
Elderly Subjects ◽  
Age Related ◽  
Significant Difference ◽  
Young Subjects ◽  
Drug Free

1. Neutrophils from drug-free elderly subjects produced approximately 50% less cyclic AMP in response to isoprenaline than did neutrophils from young subjects. A significant difference in basal cyclic AMP levels was also evident (elderly 2.8 ± 0.37; young 4.9 ± 0.36 pmol of cAMP/107 cells; P < 0.05). 2. With a range of anti-neutrophil monoclonal antibodies no evidence of age-related neutrophil population heterogeneity was found. 3. These findings indicate that the age-related decline in β-adrenoceptor responsiveness is not due to changes in the neutrophil population. 4. The present results support the hypothesis that there is a generalized decline in β-adrenoceptor-mediated responsiveness in the elderly.

scholarly journals The Role of Visual Association Cortex in Associative Memory Formation across Development

2018 ◽  
Vol 30 (3) ◽  
pp. 365-380 ◽  
Author(s):  
Maya L. Rosen ◽  
Margaret A. Sheridan ◽  
Kelly A. Sambrook ◽  
Matthew R. Peverill ◽  
Andrew N. Meltzoff ◽  
...  
Keyword(s):  
Associative Memory ◽  
Visual Processing ◽  
Memory Performance ◽  
Neural Mechanism ◽  
Association Cortex ◽  
Associative Memories ◽  
Associate Learning ◽  
Visual Association Cortex ◽  
Age Related

Associative learning underlies the formation of new episodic memories. Associative memory improves across development, and this age-related improvement is supported by the development of the hippocampus and pFC. Recent work, however, additionally suggests a role for visual association cortex in the formation of associative memories. This study investigated the role of category-preferential visual processing regions in associative memory across development using a paired associate learning task in a sample of 56 youths (age 6–19 years). Participants were asked to bind an emotional face with an object while undergoing fMRI scanning. Outside the scanner, participants completed a memory test. We first investigated age-related changes in neural recruitment and found linear age-related increases in activation in lateral occipital cortex and fusiform gyrus, which are involved in visual processing of objects and faces, respectively. Furthermore, greater activation in these visual processing regions was associated with better subsequent memory for pairs over and above the effect of age and of hippocampal and pFC activation on performance. Recruitment of these visual processing regions mediated the association between age and memory performance, over and above the effects of hippocampal activation. Taken together, these findings extend the existing literature to suggest that greater recruitment of category-preferential visual processing regions during encoding of associative memories is a neural mechanism explaining improved memory across development.

scholarly journals Age-related changes in multifinger synergies in accurate moment of force production tasks

2007 ◽  
Vol 102 (4) ◽  
pp. 1490-1501 ◽  
Author(s):  
Halla Olafsdottir ◽  
Wei Zhang ◽  
Vladimir M. Zatsiorsky ◽  
Mark L. Latash
Keyword(s):  
Hand Function ◽  
The Elderly ◽  
Time Profile ◽  
Uncontrolled Manifold ◽  
Elderly Subjects ◽  
Total Force ◽  
Dominant Hand ◽  
Total Moment ◽  
Age Related ◽  
Young Subjects

The purpose of this investigation was to document and quantify age-related differences in the coordination of fingers during a task that required production of an accurate time profile of the total moment of force by the four fingers of a hand. We hypothesized that elderly subjects would show a decreased ability to stabilize a time profile of the total moment of force, leading to larger indexes of moment variability compared with young subjects. The subjects followed a trapezoidal template on a computer screen by producing a time profile of the total moment of force while pressing down on force sensors with the four fingers of the right (dominant) hand. To quantify synergies, we used the framework of the uncontrolled manifold hypothesis. The elderly subjects produced larger total force, larger variance of both total force and total moment of force, and larger involvement of fingers that produced moment of force against the required moment direction (antagonist moment). This was particularly prominent during supination efforts. Young subjects showed covariation of commands to fingers across trials that stabilized the moment of total force (moment-stabilizing synergy), while elderly subjects failed to do so. Both subject groups showed similar indexes of covariation of commands to the fingers that stabilized the time profile of the total force. The lack of moment-stabilizing synergies may be causally related to the documented impairment of hand function with age.

scholarly journals Maximum Voluntary Activation in Nonfatigued and Fatigued Muscle of Young and Elderly Individuals

2001 ◽  
Vol 81 (5) ◽  
pp. 1102-1109 ◽  
Author(s):  
Scott K Stackhouse ◽  
Jennifer E Stevens ◽  
Samuel CK Lee ◽  
Karen M Pearce ◽  
Lynn Snyder-Mackler ◽  
...  
Keyword(s):  
Maximum Voluntary Contraction ◽  
Quadriceps Femoris ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Elderly Subjects ◽  
Central Activation ◽  
Quadriceps Femoris Muscle ◽  
Age Related ◽  
Young Subjects ◽  
Femoris Muscle

Abstract Background and Purpose. Researchers studying central activation of muscles in elderly subjects (≥65 years of age) have investigated activation in only the nonfatigued state. This study examined the ability of young and elderly people to activate their quadriceps femoris muscles voluntarily under both fatigued and nonfatigued conditions to determine the effect of central activation failure on age-related loss of force. Subjects and Methods. Twenty young subjects (11 men, 9 women; mean age=22.67 years, SD=4.14, range=18–32 years) and 17 elderly subjects (8 men, 9 women; mean age=71.5 years, SD=5.85, range=65–84 years) participated in this study. Subjects were seated on a dynamometer and stabilized. Central activation was quantified, based on the change in force produced by a 100-Hz, 12-pulse electrical train that was delivered during a 3- to 5-second isometric maximum voluntary contraction (MVC) of the quadriceps femoris muscle. Next, subjects performed 25 MVCs (a 5-second contraction with 2 seconds of rest) to fatigue the muscle. During the last MVC, central activation was measured again. Results. In the nonfatigued state, elderly subjects had lower central activation than younger subjects. In the fatigued state, this difference became larger. Discussion and Conclusion. Central activation of the quadriceps femoris muscle in elderly subjects was reduced in both the fatigued and nonfatigued states when compared with young subjects. Some part of age-related weakness, therefore, may be attributed to failure of central activation in both the fatigued and nonfatigued states.

Effect of ‘Autonomic Blockade’ on Cardiac β-Adrenergic Chronotropic Responsiveness in Healthy Young, Healthy Elderly and Endurance-Trained Elderly Subjects

1994 ◽  
Vol 87 (3) ◽  
pp. 297-302 ◽  
Author(s):  
G. A. Ford ◽  
O. F. W. James
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Geometric Mean ◽  
Cardiovascular Responses ◽  
The Elderly ◽  
Elderly Subjects ◽  
Healthy Elderly ◽  
Age Related ◽  
Autonomic Blockade ◽  
Young Subjects

1. Cardiac chronotropic responses to isoprenaline are reduced with ageing in man. It is unclear whether this is due to reduced cardiac β-adrenergic sensitivity or to age-associated differences in reflex cardiovascular responses to the vasodilatory effects of isoprenaline. Age-associated changes in physical activity are also reported to influence β-adrenergic sensitivity. 2. The aim of the present study was to determine the contribution of alterations in reflex changes in parasympathetic and sympathetic influences and physical fitness to the age-associated reduction in cardiac chronotropic responses to β-adrenergic agonists. 3. The effect of ‘autonomic blockade’ with atropine (40 μg/kg intravenously) and clonidine (4 μg/kg intravenously) on blood pressure, heart rate and chronotropic responses to intravenous bolus isoprenaline doses was determined in eight healthy young (mean age 21 years), nine healthy elderly (72 years) and 10 endurance-trained elderly (69 years) subjects. 4. Elderly subjects had a reduced increase in heart rate after atropine (young, 49 ± 9 beats/min; elderly, 36 ± 5 beats/min; endurance-trained elderly, 34 ± 12 beats/min; P < 0.01) and did not demonstrate the transient increase in systolic blood pressure after clonidine observed in young subjects (young, 11 ± 10 mmHg; elderly, −12 ± 16 mmHg; endurance-trained elderly, −18 ± 11 mmHg; P < 0.01). 5. Cardiac chronotropic sensitivity to isoprenaline after ‘autonomic blockade’ increased in the young but decreased in the elderly subjects. The isoprenaline dose that increased heart rate by 25 beats/min before and after autonomic blockade' was: young, before 1.6 μg, after 2.8 μg, P < 0.01 (geometric mean, paired test); elderly, before 6.9 μg, after 3.6 μg, P < 0.05; endurance-trained elderly, before 5.9 μg, after 4.0 μg, P < 0.05. Cardiac chronotropic sensitivity to isoprenaline was significantly reduced in elderly compared with young subjects before (P < 0.01) but was similar after (P = 0.09) ‘autonomic blockade’. Chronotropic sensitivity did not differ between healthy and endurance-trained elderly subjects before or after ‘autonomic blockade’. 6. The age-associated reduction in cardiac chronotropic responses to bolus isoprenaline is primarily due to an age-related reduction in the influence of reflex cardiovascular responses on heart rate and not to an age-related reduction in cardiac β-adrenergic sensitivity. Endurance training is not associated with altered β-adrenergic chronotropic sensitivity in the elderly. The transient pressor response to intravenously administered clonidine may be lost in ageing man.

Age Differences in Performance at Concentration: A Pilot Study

1992 ◽  
Vol 74 (2) ◽  
pp. 412-414 ◽  
Author(s):  
Joyce Chagnon ◽  
Stuart J. McKelvie
Keyword(s):  
Pilot Study ◽  
Age Differences ◽  
Visual Processing ◽  
The Elderly ◽  
Elderly Subjects ◽  
Age Related

24 subjects ranging in age from 5 to 65 years individually played Concentration in pictorial and verbal formats. Consistent with age-related declines in both general and visual processing, performance was poorest for the elderly subjects on both tasks; however, there was no evidence of children's precocity.

scholarly journals What affects the magnitude of age-related dual-task costs in working memory? The role of stimulus domain and access to semantic representations

2020 ◽  
pp. 174702182097074
Author(s):  
Agnieszka J Jaroslawska ◽  
Stephen Rhodes ◽  
Clément Belletier ◽  
Jason M Doherty ◽  
Nelson Cowan ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Dual Task ◽  
Memory Task ◽  
Semantic Representations ◽  
Younger Adults ◽  
Task Effects ◽  
Concurrent Processing ◽  
Age Related

Although there is evidence that the effect of including a concurrent processing demand on the storage of information in working memory is disproportionately larger for older than younger adults, not all studies show this age-related impairment, and the critical factors responsible for any such impairment remain elusive. Here we assess whether domain overlap between storage and processing activities, and access to semantic representations, are important determinants of performance in a sample of younger and older adults ( N = 119). We developed four versions of a processing task by manipulating the type of stimuli involved (either verbal or non-verbal) and the decision that participants had to make about the stimuli presented on the screen. Participants either had to perform a spatial judgement, in deciding whether the verbal or non-verbal item was presented above or below the centre of the screen, or a semantic judgement, in deciding whether the stimulus refers to something living or not living. The memory task was serial-ordered recall of visually presented letters. The study revealed a large increase in age-related memory differences when concurrent processing was required. These differences were smaller when storage and processing activities both used verbal materials. Dual-task effects on processing were also disproportionate for older adults. Age differences in processing performance appeared larger for tasks requiring spatial decisions rather than semantic decisions. We discuss these findings in relation to three competing frameworks of working memory and the extant literature on cognitive ageing.

Effects of Aging on Motor-Unit Control Properties

1999 ◽  
Vol 82 (5) ◽  
pp. 2081-2091 ◽  
Author(s):  
Zeynep Erim ◽  
M. Faisal Beg ◽  
David T. Burke ◽  
Carlo J. de Luca
Keyword(s):  
Firing Rate ◽  
Motor Unit ◽  
Motor Units ◽  
Elderly Subjects ◽  
Compensatory Mechanism ◽  
Type I ◽  
Firing Behavior ◽  
Firing Rates ◽  
Age Related ◽  
Young Subjects

It was hypothesized that the age-related alterations in the morphological properties of a motor unit would be accompanied by modifications in the control aspects of the motor unit, as either an adaptive or compensatory mechanism to preserve smooth force production. In specific, the objective of the study was to investigate the age-related alterations in the concurrent firing behavior of multiple motor units in the first dorsal interosseous (FDI) muscle in isometric contractions at 20 and 50% of the subject's voluntary contraction level. Analysis of the data collected from 10 young (24–37 yr of age) and 10 elderly (65–88 yr of age) subjects led to three novel observations regarding the firing behavior of aged motor units. 1) Among elderly subjects, there is a decrease in the common fluctuations that are observed among the firing rates of motor units in the young. 2) The relationship observed between the firing rate and recruitment threshold of young subjects is disturbed in the elderly. Although in young subjects, at any point in a given submaximal contraction, earlier recruited motor units have higher firing rates than later-recruited units; in aged subjects this dependency of firing rate on recruitment rank is compromised. 3) The progressive decrease observed in the firing rates of concurrently active motor units in constant-force contractions in the young is not seen in the aged. In addition to these original findings, this study provided support for earlier reports of 1) decreased average firing rates probably reflecting the slowing of the muscle, 2) a shift in recruitment thresholds toward lower force levels in line with the shift toward type I fibers, and 3) multiphasic action potential shapes indicative of the reinnervation process that takes place during aging. Taken as a whole, these findings indicate significant age-related modifications in the control properties of human motor units.

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