Contrasting Age Effects on Complexity of Tracking Force and Force Fluctuations During Monorhythmic Contraction

2020 ◽  
Vol 28 (1) ◽  
pp. 114-121
Author(s):  
Yi-Ching Chen ◽  
I-Chen Lin ◽  
Yen-Ting Lin ◽  
Wei-Min Huang ◽  
Chien-Chun Huang ◽  
...  
Keyword(s):  
Older Adults ◽  
Task Performance ◽  
Low Frequency ◽  
Total Force ◽  
Force Component ◽  
Stochastic Force ◽  
Force Fluctuations ◽  
Age Related ◽  
Pursuit Tracking ◽  
Tracking Force

This study contrasted the stochastic force component between young and older adults, who performed pursuit tracking/compensatory tracking by exerting in-phase/antiphase forces to match a sinusoidal target. Tracking force was decomposed into the force component containing the target frequency and the nontarget force fluctuations (stochastic component). Older adults with inferior task performance had higher complexity (entropy across time; p = .005) in total force. For older adults, task errors were negatively correlated with force fluctuation complexity (pursuit tracking: r = −.527 to −.551; compensatory tracking: r = −.626 to −.750). Notwithstanding an age-related increase in total force complexity (p = .004), older adults exhibited lower complexity of the stochastic force component than young adults did (low frequency: p = .017; high frequency: p = .035). Those older adults with a higher complexity of stochastic force had better task performance due to the underlying use of a richer gradation strategy to compensate for impaired oscillatory control.

Age-Related Differences in Motivational Integration and Cognitive Control

2019 ◽  
Author(s):  
Debbie Marianne Yee ◽  
Sarah L Adams ◽  
Asad Beck ◽  
Todd Samuel Braver
Keyword(s):  
Older Adults ◽  
Decision Making ◽  
Cognitive Control ◽  
Task Performance ◽  
Cognitive Task ◽  
Monetary Reward ◽  
Potential Candidate ◽  
Younger Adults ◽  
Age Related ◽  
Cognitive Task Performance

Motivational incentives play an influential role in value-based decision-making and cognitive control. A compelling hypothesis in the literature suggests that the brain integrates the motivational value of diverse incentives (e.g., motivational integration) into a common currency value signal that influences decision-making and behavior. To investigate whether motivational integration processes change during healthy aging, we tested older (N=44) and younger (N=54) adults in an innovative incentive integration task paradigm that establishes dissociable and additive effects of liquid (e.g., juice, neutral, saltwater) and monetary incentives on cognitive task performance. The results reveal that motivational incentives improve cognitive task performance in both older and younger adults, providing novel evidence demonstrating that age-related cognitive control deficits can be ameliorated with sufficient incentive motivation. Additional analyses revealed clear age-related differences in motivational integration. Younger adult task performance was modulated by both monetary and liquid incentives, whereas monetary reward effects were more gradual in older adults and more strongly impacted by trial-by-trial performance feedback. A surprising discovery was that older adults shifted attention from liquid valence toward monetary reward throughout task performance, but younger adults shifted attention from monetary reward toward integrating both monetary reward and liquid valence by the end of the task, suggesting differential strategic utilization of incentives. Together these data suggest that older adults may have impairments in incentive integration, and employ different motivational strategies to improve cognitive task performance. The findings suggest potential candidate neural mechanisms that may serve as the locus of age-related change, providing targets for future cognitive neuroscience investigations.

scholarly journals Evidence of degraded representation of speech in noise, in the aging midbrain and cortex

2016 ◽  
Vol 116 (5) ◽  
pp. 2346-2355 ◽  
Author(s):  
Alessandro Presacco ◽  
Jonathan Z. Simon ◽  
Samira Anderson
Keyword(s):  
Older Adults ◽  
Speech Processing ◽  
Background Noise ◽  
Low Frequency ◽  
Network Connectivity ◽  
Younger Adults ◽  
Auditory Temporal Processing ◽  
Age Related ◽  
Speech Envelope ◽  
Impaired Speech

Humans have a remarkable ability to track and understand speech in unfavorable conditions, such as in background noise, but speech understanding in noise does deteriorate with age. Results from several studies have shown that in younger adults, low-frequency auditory cortical activity reliably synchronizes to the speech envelope, even when the background noise is considerably louder than the speech signal. However, cortical speech processing may be limited by age-related decreases in the precision of neural synchronization in the midbrain. To understand better the neural mechanisms contributing to impaired speech perception in older adults, we investigated how aging affects midbrain and cortical encoding of speech when presented in quiet and in the presence of a single-competing talker. Our results suggest that central auditory temporal processing deficits in older adults manifest in both the midbrain and in the cortex. Specifically, midbrain frequency following responses to a speech syllable are more degraded in noise in older adults than in younger adults. This suggests a failure of the midbrain auditory mechanisms needed to compensate for the presence of a competing talker. Similarly, in cortical responses, older adults show larger reductions than younger adults in their ability to encode the speech envelope when a competing talker is added. Interestingly, older adults showed an exaggerated cortical representation of speech in both quiet and noise conditions, suggesting a possible imbalance between inhibitory and excitatory processes, or diminished network connectivity that may impair their ability to encode speech efficiently.

Aging and Recognition Memory: Changes in Regional Cerebral Blood Flow Associated with Components of Reaction Time Distributions

1999 ◽  
Vol 11 (5) ◽  
pp. 511-520 ◽  
Author(s):  
David J. Madden ◽  
Lawrence R. Gottlob ◽  
Laura L. Denny ◽  
Timothy G. Turkington ◽  
James M. Provenzale ◽  
...  
Keyword(s):  
Older Adults ◽  
Blood Flow ◽  
Young Adults ◽  
Cerebral Blood Flow ◽  
Reaction Time ◽  
Task Performance ◽  
Regional Cerebral Blood Flow ◽  
Regional Cerebral Blood ◽  
Age Related ◽  
The Mean

We used H215O positron emission tomography (PET) to measure age-related changes in regional cerebral blood flow (rCBF) during a verbal recognition memory task. Twelve young adults (20 to 29 years) and 12 older adults (62 to 79 years) participated. Separate PET scans were conducted during Encoding, Baseline, and Retrieval conditions. Each of the conditions involved viewing a series of 64 words and making a two-choice response manually. The complete reaction time (RT) distributions in each task condition were characterized in terms of an ex-Gaussian model (convolution of exponential and Gaussian functions). Parameter estimates were obtained for the mean of the exponential component (τ), representing a task-specific decision process and the mean of the Gaussian component (μ), representing residual sensory coding and response processes. Independently of age group, both μ and τ were higher in the Encoding and Retrieval conditions than in the Baseline condition, and τ was higher during Retrieval than during Encoding. Age-related slowing in task performance was evident primarily in μ. For young adults, rCBF activation in the right prefrontal cortex, in the Retrieval condition, was correlated positively with μ but not with τ. For older adults, rCBF changes (both increases and decreases) in several cortical regions were correlated with both μ and τ. The data suggest that the attentional demands of this task are relatively greater for older adults and consequently lead to the recruitment of additional neural systems during task performance.

scholarly journals Contrasting effects of fatigue on multifinger coordination in young and older adults

2013 ◽  
Vol 115 (4) ◽  
pp. 456-467 ◽  
Author(s):  
Tarkeshwar Singh ◽  
Vladimir M. Zatsiorsky ◽  
Mark L. Latash
Keyword(s):  
Older Adults ◽  
Index Finger ◽  
Force Production ◽  
The Elderly ◽  
Young Group ◽  
Voluntary Contraction ◽  
Elderly Group ◽  
Total Force ◽  
Synergy Index ◽  
Age Related

We investigated the effects of fatigue produced by timed maximal voluntary contraction (MVC) of the index finger of the right hand on performance in MVC and accurate cyclic force production tasks in right-handed young (Young group) and strength-matched elderly (Elderly group) participants. We hypothesized that, before fatigue, the Elderly group would show weaker force-stabilizing synergies and smaller adaptive changes in the synergy index during fatigue. Synergies were defined as covaried adjustments of neural commands to fingers (finger modes) across trials that stabilize total force. Fatigue caused a significant reduction in the MVC, which was larger in the Young group compared with the Elderly group for both fatigued finger (index finger) and four fingers (index, middle, ring, and little fingers pressing together). Indexes of finger enslaving (lack of individuation) increased with fatigue in both groups. The index of force-stabilizing synergies was similar for the two groups before fatigue, while its increase with fatigue was significantly larger in the Elderly group compared with the Young group. We infer that changes in the indexes of finger interaction (enslaving) and coordination (synergy) with age seem to be correlated with changes in muscle strength. This correlation may be causally related to the progressive death of neurons at different levels of the neuromotor hierarchy. The surprisingly large changes in the synergy index with fatigue in older adults suggest that, by itself, aging does not necessarily lead to impairment in synergic control. Strength training may be a method to avoid age-related decrement in finger interaction and coordination.

Age-Related Differences in Learning Incidental Environmental Information

2005 ◽  
Vol 49 (2) ◽  
pp. 190-194 ◽  
Author(s):  
Kelly E. Caine ◽  
Timothy A. Nichols ◽  
Arthur D. Fisk ◽  
Wendy A. Rogers
Keyword(s):  
Older Adults ◽  
Task Performance ◽  
Target Letter ◽  
Target Location ◽  
Environmental Information ◽  
Younger Adults ◽  
Age Related ◽  
Improved Performance ◽  
Verbal Knowledge

Incidental environmental information is consistent, potentially beneficial, information that is not necessary for successful task performance (i.e., is seemingly unrelated to the task). In the present study, older and younger participants searched for target letters among distractor letters both of which were laid upon color environments, such that certain color environments predictively correlated with target letter location at varying degrees of consistency. Neither group could express verbal knowledge of the pattern of the environmental information although younger but not older adults showed improved performance in conditions where incidental information cued target location. The findings suggest that younger adults can benefit from incidental environmental information even when they cannot express that it is present in a task but that older adults may need additional cues to benefit from the information.

Changes in self-estimated step-over ability among older adults: A 3-year follow-up study

2020 ◽  
Author(s):  
Ryota Sakurai ◽  
Yoshinori Fujiwara ◽  
Hiroyuki Suzuki ◽  
Susumu Ogawa ◽  
Takahiro Higuchi ◽  
...  
Keyword(s):  
Older Adults ◽  
Estimation Error ◽  
Low Frequency ◽  
Community Dwelling ◽  
Physical Ability ◽  
Age Related ◽  
Risk Of Falls ◽  
Falls In Older Adults ◽  
Step Over

Abstract Objectives There is a growing body of literature examining age-related overestimation of one’s own physical ability, which is a potential risk of falls in older adults, but it is unclear what leads them to overestimate. This study aimed to examine 3-year longitudinal changes in self-estimated step-over ability, along with one key risk factor: low frequency of going outdoors (FG), which is a measure of poor daily physical activity. Method This cohort study included 116 community-dwelling older adults who participated in baseline and 3-year follow-up assessments. The step-over test was used to measure both the self-estimated step-over bar height (EH) and the actual bar height (AH). Low FG was defined as going outdoors either every few days or less at baseline. Results The number of participants who overestimated their step-over ability (EH>AH) significantly increased from 10.3% to 22.4% over the study period. AH was significantly lower at follow-up than at baseline in both participants with low and high FGs. Conversely, among participants with low FG, EH was significantly higher at follow-up than at baseline, resulting in increased self-estimation error toward overestimation. Regression model showed that low FG was independently associated with increased error in estimation (i.e., tendency to overestimate) at follow-up. Discussion The present study indicated that self-overestimated physical ability in older adults is not only due to decreased physical ability but also due to increased self-estimation of one’s ability as a function of low FG. Active lifestyle may be critical for maintaining accurate estimations of one’s own physical ability.

Retention of Multiple-Task Performance: Age-Related Differences

1996 ◽  
Vol 40 (3) ◽  
pp. 128-132 ◽  
Author(s):  
Richard A. Sit ◽  
Arthur D. Fisk
Keyword(s):  
Older Adults ◽  
Task Performance ◽  
Complex Task ◽  
Processing Efficiency ◽  
Work Task ◽  
Age Related ◽  
Strategic Allocation ◽  
The Relationship ◽  
Multiple Task ◽  
Synthetic Work

This study examined the relationship between retention of both multiple-task performance and the micro-components of a complex task. Young and older adults trained on a synthetic work task (Elsmore, 1994) with both groups acquiring skill in performing the complex task. After a five month retention period, older adults' initial performance on the multiple-task declined significantly more than younger adults. Both groups of adults regained their final trained level of performance after only four 5-minute trials. However, throughout the retention trials older adults only emphasized a single component of the complex task. Young adults successfully allocated attention to all task components. These and other aspects of the data suggest that a major locus of age-related decline in complex task performance is due to differential loss in strategic allocation of attention to component tasks. The data also show how measuring multiple-task performance may underestimate lack of component processing efficiency.

Age-Related Differences in the Acquisition, Transfer, and Retention of Using an Automatic Teller Machine

1998 ◽  
Vol 42 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Brian A. Jamieson ◽  
Wendy A. Rogers
Keyword(s):  
Older Adults ◽  
Retention Interval ◽  
Task Performance ◽  
Transfer Task ◽  
Younger Adults ◽  
Automatic Teller Machine ◽  
Age Related ◽  
Transfer And Retention ◽  
Performance Ability ◽  
Related Transaction

The present study trained older and younger adults to use a simulated automatic teller machine. Training consisted of practice on transactions with immediate, substantial feedback provided by the experimenter. Both younger and older adults' performance improved with practice on the task. Performance declined when participants had to transfer to related transaction types on a different version of the simulator. After a one month retention interval, no significant declines in performance were detected for the transfer task. Older adults were shown to have achieved higher levels of performance than seen in related types of studies, and were able to transfer and retain performance ability.

Age-Related Differences in Processing Dynamic Information to Identify Vowel Quality

1992 ◽  
Vol 35 (4) ◽  
pp. 892-902 ◽  
Author(s):  
Robert Allen Fox ◽  
Lida G. Wall ◽  
Jeanne Gokcen
Keyword(s):  
Older Adults ◽  
Vowel Quality ◽  
Perceptual Cues ◽  
Dynamic Information ◽  
Process Dynamic ◽  
Center Condition ◽  
Age Related ◽  
Control Version ◽  
Older Subjects ◽  
Whole Word

This study examined age-related differences in the use of dynamic acoustic information (in the form of formant transitions) to identify vowel quality in CVCs. Two versions of 61 naturally produced, commonly occurring, monosyllabic English words were created: a control version (the unmodified whole word) and a silent-center version (in which approximately 62% of the medial vowel was replaced by silence). A group of normal-hearing young adults (19–25 years old) and older adults (61–75 years old) identified these tokens. The older subjects were found to be significantly worse than the younger subjects at identifying the medial vowel and the initial and final consonants in the silent-center condition. These results support the hypothesis of an age-related decrement in the ability to process dynamic perceptual cues in the perception of vowel quality.

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