scholarly journals Speech Perception in Complex Acoustic Environments: Developmental Effects

2017 ◽  
Vol 60 (10) ◽  
pp. 3001-3008 ◽  
Author(s):  
Lori J. Leibold
Keyword(s):  
Speech Recognition ◽  
Time Course ◽  
Auditory Masking ◽  
Current State ◽  
Developmental Effects ◽  
Hearing Status ◽  
Age Related ◽  
Acoustic Environments ◽  
Competing Speech ◽  
Age Related Changes

Purpose The ability to hear and understand speech in complex acoustic environments follows a prolonged time course of development. The purpose of this article is to provide a general overview of the literature describing age effects in susceptibility to auditory masking in the context of speech recognition, including a summary of findings related to the maturation of processes thought to facilitate segregation of target from competing speech. Method Data from published and ongoing studies are discussed, with a focus on synthesizing results from studies that address age-related changes in the ability to perceive speech in the presence of a small number of competing talkers. Conclusions This review provides a summary of the current state of knowledge that is valuable for researchers and clinicians. It highlights the importance of considering listener factors, such as age and hearing status, as well as stimulus factors, such as masker type, when interpreting masked speech recognition data. Presentation Video http://cred.pubs.asha.org/article.aspx?articleid=2601620

scholarly journals Closing the Capacity-Ability Gap: Using Technology to Support Aging With Disability

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Tracy L Mitzner ◽  
Jon A Sanford ◽  
Wendy A Rogers
Keyword(s):  
Great Promise ◽  
User Requirements ◽  
Intervention Model ◽  
Current State ◽  
Age Related ◽  
Wide Range ◽  
Technology Intervention ◽  
Bridge Models ◽  
Age Related Changes

Abstract There is a critical need to develop supports for older adults who have a wide range of abilities, including those aging with long-term impairments. Without appropriate support, many individuals will be functioning below optimal levels and will face participation barriers. Technology holds great promise to provide individualized support for a wide range of abilities and for a variety of domains. To ensure technology interventions are designed well and meet research-documented user requirements, we need more specific, actionable models to provide guidance for those developing and designing interventions. In this paper, we present the TechSAge Aging and Disability Model to bridge models from the aging and disability literatures and to disambiguate the population of individuals aging into disability from those aging with disability (i.e., pre-existing impairments). We also present the TechSAge Technology Intervention Model to support aging with pre-existing impairments, which provides direction and touch points for technology interventions. These models reflect the complex and dynamic interaction between age-related changes and an individual’s prior capabilities and limitations. We describe the need for these models with respect to filling a gap in the disability and aging literature by highlighting the importance of differentiating between age-related changes and long-term impairments when designing interventions. We also show the need for quantitative and qualitative data to refine the models given complexities of the current state of the literature and survey data. The TechSAge Technology Intervention Model can be used to drive and inform technology redesign and development.

scholarly journals Age-related changes in deformability of human erythrocytes

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 275-282 ◽  
Author(s):  
SP Sutera ◽  
RA Gardner ◽  
CW Boylan ◽  
GL Carroll ◽  
KC Chang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Time Course ◽  
Dynamic Equilibrium ◽  
Chemical Properties ◽  
Significant Loss ◽  
Human Erythrocytes ◽  
Mean Corpuscular Hemoglobin ◽  
Mean Cell Volume ◽  
Age Related ◽  
Age Related Changes

Abstract The present study was designed to further the characterization of age- related changes in the deformability of human erythrocytes. The top (approximately young) and bottom (approximately old) 10% fractions of density-separated red cells from ten normal donors were subjected to graded levels of shear stress in a rheoscope. Measurements were made of steady-state elongation (cells tank treading in a state of dynamic equilibrium) and the time course of shape recovery following abrupt cessation of shear. In parallel with the rheologic experiments, several physical and chemical properties were assayed to determine correlates of mechanical properties. These included mean cell volume, mean corpuscular hemoglobin concentration, type A1 hemoglobin, glucosylation of membrane proteins, and membrane phospholipid and protein concentration. The microrheologic observations revealed that only about 90% of the old cells retained their capacity to tank tread. However, the tank-treading cells elongated less than their younger counterparts at corresponding levels of shear stress, thus demonstrating a reduced level of deformability. Further analysis of the data indicates that increases in membrane viscosity and elastic modulus along with a significant loss in excess surface area contribute to the limitation of the ability of the older cells to change shape.

Microgenesis and Ontogenesis of Perceptual Organization

2005 ◽  
Vol 16 (4) ◽  
pp. 282-290 ◽  
Author(s):  
Ruth Kimchi ◽  
Batsheva Hadad ◽  
Marlene Behrmann ◽  
Stephen E. Palmer
Keyword(s):  
Visual Search ◽  
Perceptual Organization ◽  
Time Course ◽  
Developmental Trajectories ◽  
Age Related ◽  
Multiple Processes ◽  
The One ◽  
Small Elements ◽  
Age Related Changes ◽  
Speeded Classification

In two experiments, visual search and speeded classification were used to study perception of hierarchical patterns among participants aged 5 to 23 years. Perception of global configurations of few-element patterns and local elements of many-element patterns showed large age-related improvements. Only minor age-related changes were observed in perception of global configurations of many-element patterns and local elements of few-element patterns. These results are consistent with prior microgenetic analyses using hierarchical patterns. On the one hand, the rapid and effortless grouping of many small elements and the individuation of few large elements both mature by age 5. In contrast, the time-consuming and effortful grouping of few large elements and the individuation of many small elements improve substantially with age, primarily between ages 5 and 10. These findings support the view that perceptual organization involves multiple processes that vary in time course, attentional demands, and developmental trajectories.

Increased Calcium Buffering in Basal Forebrain Neurons During Aging

1998 ◽  
Vol 80 (1) ◽  
pp. 350-364 ◽  
Author(s):  
David Murchison ◽  
William H. Griffith
Keyword(s):  
Basal Forebrain ◽  
Time Course ◽  
Smooth Endoplasmic Reticulum ◽  
Medial Septum ◽  
Diagonal Band ◽  
Age Related ◽  
Calcium Buffering ◽  
Intracellular Ca ◽  
Forebrain Neurons ◽  
Age Related Changes

Murchison, David and William H. Griffith. Increased calcium buffering in basal forebrain neurons during aging. J. Neurophysiol. 80: 350–364, 1998. Alterations of neuronal calcium (Ca2+) homeostasis are thought to underlie many age-related changes in the nervous system. Basal forebrain neurons are susceptible to changes associated with aging and to related dysfunctions such as Alzheimer's disease. It recently was shown that neurons from the medial septum and nucleus of the diagonal band (MS/nDB) of aged (24–27 mo) F344 rats have an increased current influx through voltage-gated Ca2+ channels (VGCCs) relative to those of young (1–4.5 mo) rats. Possible age-related changes in Ca2+ buffering in these neurons have been investigated using conventional whole cell and perforated-patch voltage clamp combined with fura-2 microfluorimetric techniques. Basal intracellular Ca2+ concentrations ([Ca2+]i), Ca2+ influx, Ca2+ transients (Δ[Ca2+]i), and time course of Δ[Ca2+]i were quantitated, and rapid Ca2+ buffering values were calculated in MS/nDB neurons from young and aged rats. The involvement of the smooth endoplasmic reticulum (SER) was examined with the SER Ca2+ uptake blocker, thapsigargin. An age-related increase in rapid Ca2+ buffering and Δ[Ca2+]i time course was observed, although basal [Ca2+]i was unchanged with age. The SER and endogenous diffusible buffering mechanisms were found to have roles in Ca2+ buffering, but they did not mediate the age-related changes. These findings suggest a model in which some aging central neurons could compensate for increased Ca2+ influx with greater Ca2+ buffering.

scholarly journals A constituent-based model of age-related changes in conduit arteries

2011 ◽  
Vol 301 (4) ◽  
pp. H1286-H1301 ◽  
Author(s):  
Alkiviadis Tsamis ◽  
Alexander Rachev ◽  
Nikos Stergiopulos
Keyword(s):  
Mechanical Properties ◽  
Time Course ◽  
Present Report ◽  
Finite Elasticity ◽  
Mixture Theory ◽  
Constrained Mixture Theory ◽  
Age Related ◽  
Constrained Mixture ◽  
Arterial Tissue ◽  
Age Related Changes

In the present report, a constituent-based theoretical model of age-related changes in geometry and mechanical properties of conduit arteries is proposed. The model was based on the premise that given the time course of the load on an artery and the accumulation of advanced glycation end-products in the arterial tissue, the initial geometric dimensions and properties of the arterial tissue can be predicted by a solution of a boundary value problem for the governing equations that follow from finite elasticity, structure-based constitutive modeling within the constrained mixture theory, continuum damage theory, and global growth approach for stress-induced structure-based remodeling. An illustrative example of the age-related changes in geometry, structure, composition, and mechanical properties of a human thoracic aorta is considered. Model predictions were in good qualitative agreement with available experimental data in the literature. Limitations and perspectives for refining the model are discussed.

scholarly journals Inter- and Intra-Hemispheric Age-Related Remodeling in Visuo-Spatial Working Memory

2022 ◽  
Vol 13 ◽  
Author(s):  
Chiara F. Tagliabue ◽  
Greta Varesio ◽  
Veronica Mazza
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Time Course ◽  
Temporal Dynamics ◽  
Spatial Working Memory ◽  
Event Related Potential ◽  
Eeg Analysis ◽  
Stimulus Processing ◽  
Age Related ◽  
Age Related Changes

Electroencephalography (EEG) studies investigating visuo-spatial working memory (vWM) in aging typically adopt an event-related potential (ERP) analysis approach that has shed light on the age-related changes during item retention and retrieval. However, this approach does not fully enable a detailed description of the time course of the neural dynamics related to aging. The most frequent age-related changes in brain activity have been described by two influential models of neurocognitive aging, the Hemispheric Asymmetry Reduction in Older Adults (HAROLD) and the Posterior-Anterior Shift in Aging (PASA). These models posit that older adults tend to recruit additional brain areas (bilateral as predicted by HAROLD and anterior as predicted by PASA) when performing several cognitive tasks. We tested younger (N = 36) and older adults (N = 35) in a typical vWM task (delayed match-to-sample) where participants have to retain items and then compare them to a sample. Through a data-driven whole scalp EEG analysis we aimed at characterizing the temporal dynamics of the age-related activations predicted by the two models, both across and within different stages of stimulus processing. Behaviorally, younger outperformed older adults. The EEG analysis showed that older adults engaged supplementary bilateral posterior and frontal sites when processing different levels of memory load, in line with both HAROLD and PASA-like activations. Interestingly, these age-related supplementary activations dynamically developed over time. Indeed, they varied across different stages of stimulus processing, with HAROLD-like modulations being mainly present during item retention, and PASA-like activity during both retention and retrieval. Overall, the present results suggest that age-related neural changes are not a phenomenon indiscriminately present throughout all levels of cognitive processing.

scholarly journals Age-Related Changes in the Time Course of Vigilant Attention During 40 Hours Without Sleep in Men

SLEEP ◽  
2006 ◽  
Vol 29 (1) ◽  
pp. 55-57 ◽  
Author(s):  
Martin Adam ◽  
Julia V. Rétey ◽  
Ramin Khatami ◽  
Hans-Peter Landolt
Keyword(s):  
Time Course ◽  
Age Related ◽  
Age Related Changes
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