Aging Degrades the Neural Encoding of Simple and Complex Sounds in the Human Brainstem

2013 ◽  
Vol 24 (07) ◽  
pp. 590-599 ◽  
Author(s):  
Christopher G. Clinard ◽  
Kelly L. Tremblay
Keyword(s):  
Phase Coherence ◽  
Neural Representation ◽  
Neural Encoding ◽  
Aging Effects ◽  
Complex Sounds ◽  
Frequency Following Response ◽  
Hearing Sensitivity ◽  
Normal Limits ◽  
Age Related ◽  
Impaired Speech

Background: Older adults, with or without normal peripheral hearing sensitivity, have difficulty understanding speech. This impaired speech perception may, in part, be due to desynchronization affecting the neural representation of acoustic features. Here we determine if phase-locked neural activity generating the brainstem frequency-following response (FFR) exhibits age-related desynchronization and how this degradation affects the neural representation of simple and complex sounds. Purpose: The objectives of this study were to (1) characterize the effects of age on the neural representation of simple tones and complex consonant-vowel stimuli, (2) determine if sustained and transient components of the FFR are differentially affected by age, and (3) determine if the inability to encode a simple signal predicts degradation in representation for complex speech signals. Research Design: Correlational Study Sample: Thirty four adults (aged 22–77 yr) with hearing thresholds falling within normal limits. Data Collection and Analysis: Stimuli used to evoke FFRs were 1000 Hz tone bursts as well as a consonant-vowel /da/ sound. Results: The neural representation of simple (tone) and complex (/da/) stimuli declines with advancing age. Tone-FFR phase coherence decreased as chronological age increased. For the consonant-vowel FFRs, transient onset and offset response amplitudes were smaller, and offset responses were delayed with age. Sustained responses at the onset of vowel periodicity were prolonged in latency and smaller in amplitude as age increased. FFT amplitude of the consonant-vowel FFR fundamental frequency did not significantly decline with increasing age. The ability to encode a simple signal was related to degradation in the neural representation of a complex, speechlike sound. Tone-FFR phase coherence was significantly related to the later vowel response components but not the earlier vowel components. Conclusions: FFR components representing the tone and consonant-vowel /da/ stimulus were negatively affected by age, showing age-related reductions in response synchrony and amplitude, as well as prolonged latencies. These aging effects were evident in middle age, even in the absence of significant hearing loss.

scholarly journals Evolving perspectives on the sources of the frequency-following response

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Emily B. J. Coffey ◽  
Trent Nicol ◽  
Travis White-Schwoch ◽  
Bharath Chandrasekaran ◽  
Jennifer Krizman ◽  
...  
Keyword(s):  
Neural Encoding ◽  
Complex Sounds ◽  
Frequency Following Response ◽  
Auditory Neuroscience ◽  
Non Invasive ◽  
Auditory Processes ◽  
The Brain

Abstract The auditory frequency-following response (FFR) is a non-invasive index of the fidelity of sound encoding in the brain, and is used to study the integrity, plasticity, and behavioral relevance of the neural encoding of sound. In this Perspective, we review recent evidence suggesting that, in humans, the FFR arises from multiple cortical and subcortical sources, not just subcortically as previously believed, and we illustrate how the FFR to complex sounds can enhance the wider field of auditory neuroscience. Far from being of use only to study basic auditory processes, the FFR is an uncommonly multifaceted response yielding a wealth of information, with much yet to be tapped.

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.

Endokrinológiai tényezők és metabolikus folyamatok szerepe az élettartam szabályozásában

2021 ◽  
Vol 162 (33) ◽  
pp. 1318-1327
Author(s):  
Tamás Halmos ◽  
Ilona Suba
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Life Expectancy ◽  
Significant Risk ◽  
Low Grade ◽  
Aging Effects ◽  
Protective Function ◽  
Beneficial Effects ◽  
Age Related

Összefoglaló. Az emberek a lehető leghosszabb ideig akarnak élni, jó egészségben. Ha kiküszöbölnénk a kedvezőtlen külső körülményeket, a várható élettartam meghaladhatná a 100 évet. A 20. és 21. században a jóléti társadalmakban a várható élettartam jelentősen megnőtt, így Magyarországon is. Az áttekintett irodalom alapján megvizsgáltuk, hogy a genetika és az öröklődés mellett milyen endokrinológiai és metabolikus tényezők játszanak szerepet az élet meghosszabbításában. Megvizsgáltunk minden endogén tényezőt, amely pozitívan vagy negatívan befolyásolhatja az életkorral összefüggő betegségeket (Alzheimer-kór, szív- és érrendszeri betegségek, rák) és az élettartamot. Kiemeltük a hyperinsulinaemia, az inzulinrezisztencia, a metabolikus szindróma öregedést gyorsító hatását, az inzulinszerű növekedési hormon-1 ellentmondásos szerepét, valamint az élet meghosszabbításában részt vevő, újabban felfedezett peptideket, mint a klotho és a humanin. Ismertettük a mitochondriumok szerepét az élettartam meghatározásában, bemutattuk a mitohormesis folyamatát és annak stresszvédő funkcióját. Bemutattuk a rapamicin célszervét, az mTOR-t, amelynek gátlása meghosszabbítja az élettartamot, valamint a szirtuinokat. Kitértünk az autophagia folyamatára, és ismertettük a szenolitikumok szerepét az öregedésben. Az időskori autoimmunitás csökkenése hozzájárul az élettartam rövidüléséhez, utaltunk a thymus koordináló szerepére. Kiemeltük a bélmikrobiom fontos szerepét az élettartam szabályozásában. Hivatkoztunk a „centenáriusok” megfigyeléséből nyert humánadatokra. Megvizsgáltuk, milyen beavatkozási lehetőségek állnak rendelkezésre az egészségben tölthető élettartam meghosszabbításához. Az életmódbeli lehetőségek közül kiemeltük a kalóriabevitel-csökkentés és a testmozgás jótékony szerepét. Megvizsgáltuk egyes gyógyszerek feltételezett hatásait. Ezek közé tartozik a metformin, az akarbóz, a rezveratrol. E gyógyszerek mindegyikének hatása hasonló a kalóriamegszorításéhoz. Nincs olyan „csodaszer”, amely igazoltan meghosszabbítja az élettartamot emberben. Egyes géneknek és génmutációknak jótékony hatásuk van, de ezt környezeti tényezők, betegségek, balesetek és más külső ártalmak módosíthatják. Kiemeljük az elhízás, az alacsony fokozatú gyulladás és az inzulinrezisztencia öregedésre gyakorolt gyorsító hatását. A metabolikus szindróma elterjedtsége miatt ez jelentős népegészségügyi kockázatot jelent. Az inzulin, a növekedési hormon és az inzulinszerű növekedési faktorok hatásainak értékelése továbbra is ellentmondásos. Az egészséges, szellemileg és fizikailag aktív életmód, a kalóriacsökkentés mindenképpen előnyös. Az életet meghosszabbító szerek értékelése még vitatott. Orv Hetil. 2021; 162(33): 1318–1327. Summary. People want to live as long as possible in good health. If we eliminate the unfavorable external conditions, the life expectancy could exceed 100 years. In the 20th and 21th centuries, life expectancy in welfare societies increased significantly, including in Hungary. Based on the reviewed literature, we examined what endocrinological and metabolic factors play a role in prolonging life in addition to genetics and inheritance. We examined all endogenous factors that can positively or negatively affect age-related diseases (Alzheimer’s disease, cardiovascular disease, cancer) and longevity. We highlighted the aging effects of hyperinsulinemia, insulin resistance, metabolic syndrome, the controversial role of insulin-like growth factor-1, and more recently discovered peptides involved in prolonging lifespan, such as klotho and humanin. We described the role of mitochondria in determining longevity, we demonstrated the process of mitohormesis and its stress-protective function. We presented the target organ of rapamycin, mTOR, the inhibition of which prolongs lifespan, as well as sirtuins. We covered the process of autophagy and described the role of senolytics in aging. The decrease in autoimmunity in old age contributes to the shortening of life expectancy, we referred to the coordinating role of the thymus. We highlighted the important role of intestinal microbiome in the regulation of longevity. We referred to human data obtained from observations on “centenarians”. We examined what intervention options are available to prolong healthy life expectancy. Among the lifestyle options, we highlighted the beneficial role of calorie reduction and exercise. We examined the putative beneficial effects of some drugs. These include metformin, acarbose, resveratrol. The effect of each of these drugs is similar to calorie restriction. There is no “miracle cure” that has been shown to prolong life-span in humans. Some genes and gene mutations have beneficial effects, but this can be modified by environmental factors, diseases, accidents, and other external harms. We highlight the accelerating effects of obesity, low-grade inflammation, and insulin resistance on aging. Due to the prevalence of metabolic syndrome, this poses a significant risk to public health. The assessment of the effects of insulin, growth hormone, and insulin-like growth factors remains controversial. A healthy, mentally and physically active lifestyle, calorie reduction is definitely beneficial. The evaluation of life-prolonging agents is still controversial. Orv Hetil. 2021; 162(33): 1318–1327.

scholarly journals Role of the Zebra Finch Auditory Thalamus in Generating Complex Representations for Natural Sounds

2010 ◽  
Vol 104 (2) ◽  
pp. 784-798 ◽  
Author(s):  
Noopur Amin ◽  
Patrick Gill ◽  
Frédéric E. Theunissen
Keyword(s):  
Receptive Fields ◽  
Neural Representation ◽  
Natural Sounds ◽  
Auditory Midbrain ◽  
Complex Sounds ◽  
Auditory Thalamus ◽  
Spectrotemporal Receptive Fields ◽  
Primary Sensory Cortex ◽  
Relay Nucleus ◽  
Field L

We estimated the spectrotemporal receptive fields of neurons in the songbird auditory thalamus, nucleus ovoidalis, and compared the neural representation of complex sounds in the auditory thalamus to those found in the upstream auditory midbrain nucleus, mesencephalicus lateralis dorsalis (MLd), and the downstream auditory pallial region, field L. Our data refute the idea that the primary sensory thalamus acts as a simple, relay nucleus: we find that the auditory thalamic receptive fields obtained in response to song are more complex than the ones found in the midbrain. Moreover, we find that linear tuning diversity and complexity in ovoidalis (Ov) are closer to those found in field L than in MLd. We also find prevalent tuning to intermediate spectral and temporal modulations, a feature that is unique to Ov. Thus even a feed-forward model of the sensory processing chain, where neural responses in the sensory thalamus reveals intermediate response properties between those in the sensory periphery and those in the primary sensory cortex, is inadequate in describing the tuning found in Ov. Based on these results, we believe that the auditory thalamic circuitry plays an important role in generating novel complex representations for specific features found in natural sounds.

scholarly journals Age-related differences in binaural masking level differences: behavioral and electrophysiological evidence

2018 ◽  
Vol 120 (6) ◽  
pp. 2939-2952 ◽  
Author(s):  
Samira Anderson ◽  
Robert Ellis ◽  
Julie Mehta ◽  
Matthew J. Goupell
Keyword(s):  
Aging Effect ◽  
Normal Hearing ◽  
Behavioral Experiment ◽  
Spatial Cues ◽  
Sound Sources ◽  
Frequency Following Response ◽  
Binaural Processing ◽  
Threshold Difference ◽  
Age Related ◽  
Effects Of Aging

The effects of aging and stimulus configuration on binaural masking level differences (BMLDs) were measured behaviorally and electrophysiologically, using the frequency-following response (FFR) to target brainstem/midbrain encoding. The tests were performed in 15 younger normal-hearing (<30 yr) and 15 older normal-hearing (>60 yr) participants. The stimuli consisted of a 500-Hz target tone embedded in a narrowband (50-Hz bandwidth) or wideband (1,500-Hz bandwidth) noise masker. The interaural phase conditions included NoSo (tone and noise presented interaurally in-phase), NoSπ (noise presented interaurally in-phase and tone presented out-of-phase), and NπSo (noise presented interaurally out-of-phase and tone presented in-phase) configurations. In the behavioral experiment, aging reduced the magnitude of the BMLD. The magnitude of the BMLD was smaller for the NoSo–NπSo threshold difference compared with the NoSo–NoSπ threshold difference, and it was also smaller in narrowband compared with wideband conditions, consistent with previous measurements. In the electrophysiology experiment, older participants had reduced FFR magnitudes and smaller differences between configurations. There were significant changes in FFR magnitude between the NoSo to NoSπ configurations but not between the NoSo to NπSo configurations. The age-related reduction in FFR magnitudes suggests a temporal processing deficit, but no correlation was found between FFR magnitudes and behavioral BMLDs. Therefore, independent mechanisms may be contributing to the behavioral and neural deficits. Specifically, older participants had higher behavioral thresholds than younger participants for the NoSπ and NπSo configurations but had equivalent thresholds for the NoSo configuration. However, FFR magnitudes were reduced in older participants across all configurations. NEW & NOTEWORTHY Behavioral and electrophysiological testing reveal an aging effect for stimuli presented in wideband and narrowband noise conditions, such that behavioral binaural masking level differences and subcortical spectral magnitudes are reduced in older compared with younger participants. These deficits in binaural processing may limit the older participant's ability to use spatial cues to understand speech in environments containing competing sound sources.

Evaluation of Representative Piping Systems Designed by Implicit Fatigue Concept

2008 ◽  
Author(s):  
Shin-Beom Choi ◽  
Sun-Hye Kim ◽  
Yoon-Suk Chang ◽  
Jae-Boong Choi ◽  
Young-Jin Kim ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Nuclear Power ◽  
Heat Removal ◽  
Environmental Water ◽  
Lessons Learned ◽  
Metal Fatigue ◽  
Aging Effects ◽  
Age Related ◽  
Piping Systems ◽  
Surge Line

NUREG-1801 provides generic aging lessons learned to manage aging effects that may occur during continued operation beyond the design life of nuclear power plant. According to this report, the metal fatigue, among several age-related degradation mechanisms, is identified as one of time-limited aging analysis item. The objective of this paper is to introduce fatigue life evaluation of representative surge line and residual heat removal system piping which was designed by implicit fatigue concept. For the back-fitting evaluation employing explicit fatigue concept, detailed parametric CFD as well as FE analyses results are used. The well-known ASME Section III NB-3600 procedure is adopted for the metal fatigue and NUREG/CR-5704 procedure is further investigated to deal with additional environmental water effects. With regard to the environmental effect evaluation, two types of fatigue life correction factors are considered, such as maximum Fen and individual Fen. As a result, it was proven that a thermal stratification phenomenon is the governing factor in metal fatigue life of the surge line and strain rate is the most important parameter affecting the environmental fatigue life of both piping. The evaluation results will be used as technical bases for continued operation of OPR 1000 plant.

scholarly journals Pregnancy in acromegaly is safe and is associated with improvements in IGF-1 concentrations

2019 ◽  
Vol 180 (4) ◽  
pp. K21-K29 ◽  
Author(s):  
Anne Marie Hannon ◽  
Triona O’Shea ◽  
Claire A Thompson ◽  
Mark J Hannon ◽  
Rosemary Dineen ◽  
...  
Keyword(s):  
Case Series ◽  
Later Life ◽  
Reference Level ◽  
Somatostatin Analogue ◽  
Biochemical Control ◽  
Normal Range ◽  
Normal Limits ◽  
Age Related ◽  
Plasma Gh ◽  
Pituitary Macroadenomas

Pregnancy is rarely reported in acromegaly. Many patients are diagnosed in later life and younger patients may have subfertility due to hypopituitarism. We present a case series of 17 pregnancies in 12 women with acromegaly. Twelve women with acromegaly who completed pregnancy were identified from centres involved in the Irish Pituitary Study. Eleven women had pituitary macroadenomas and one woman had a microadenoma. Only 5/17 pregnancies had optimal biochemical control of acromegaly preconception, as defined by IGF-1 concentration in the age-related reference level and plasma GH concentration of <2 μg/L. In 6/17 pregnancies, dopamine agonist treatment was continued during pregnancy; all other acromegaly treatments were discontinued during pregnancy. Effect of pregnancy on acromegaly: No patient developed new visual field abnormalities, or symptoms suggestive of tumour expansion during pregnancy. In 9/12 patients, plasma IGF-1 concentrations that were elevated preconception normalised during pregnancy. There was a reduction in plasma IGF-1 concentrations, though not into the normal range, in a further two pregnancies. Effect of acromegaly on pregnancy: 15 healthy babies were born at term; one patient underwent emergency C-section at 32 weeks for pre-eclampsia, and one twin pregnancy had an elective C-section at 35 weeks’ gestation. Blood pressure remained within normal limits in the remainder of the pregnancies. Gestational diabetes did not develop in any pregnancy. Our data suggests that pregnancy in women with acromegaly is generally safe, from a maternal and foetal perspective. Furthermore, biochemical control tends to improve despite the withdrawal of somatostatin analogue therapy during pregnancy.

scholarly journals Sex-dependent Pathological Aging Effect on Caudate Functional Connectivity in Mild Cognitive Impairment

2021 ◽  
Author(s):  
Zhengshi Yang ◽  
Jessica Z.K. Caldwell ◽  
Jeffrey L. Cummings ◽  
Aaron Ritter ◽  
Jefferson W. Kinney ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Aging Effect ◽  
Analysis Of Covariance ◽  
Aging Effects ◽  
Mixed Effect ◽  
Effect Analysis ◽  
Pathological Aging ◽  
Age Related

Abstract Purpose To assess the pathological aging effect on caudate functional connectivity among mild cognitive impairment (MCI) participants and examine whether and how sex and amyloid contribute to this process. Materials and Methods 277 functional magnetic resonance imaging (fMRI) sessions from 163 cognitive normal (CN) older adults and 309 sessions from 139 participants with MCI were included as the main sample in our analysis. Pearson’s correlation was used to characterize the functional connectivity (FC) between caudate and each brain region, then caudate nodal strength was computed to quantify the overall caudate FC strength. Association analysis between caudate nodal strength and age was carried out in MCI and CN separately using linear mixed effect (LME) model with covariates (education, handedness, sex, Apolipoprotein E4 and intra-subject effect). Analysis of covariance was conducted to investigate sex, amyloid status and their interaction effects on aging with the fMRI data subset having amyloid status available. LME model was applied to women and men separately within MCI group to evaluate aging effects on caudate nodal strength and each region’s connectivity with caudate. We then evaluated the roles of sex and amyloid status in the associations of neuropsychological scores with age or caudate nodal strength. An independent cohort was used to validate the sex-dependent aging effects in MCI. Results The MCI group had significantly stronger age-related increase of caudate nodal strength compared to the CN group. Analyzing women and men separately revealed that the aging effect on caudate nodal strength among MCI participants was significant only for women (left: P=6.23x10−7, right: P=3.37x10−8), but not for men (P>0.3 for bilateral caudate). The aging effects on caudate nodal strength were not significantly mediated by brain amyloid burden. Caudate connectivity with ventral prefrontal cortex substantially contributed to the aging effect on caudate nodal strength in women with MCI. Higher caudate nodal strength is significantly related to worse cognitive performance in women but not in men with MCI. Conclusion Sex modulates the pathological aging effects on caudate nodal strength in MCI regardless of amyloid status. Caudate nodal strength may be a sensitive biomarker of pathological aging in women with MCI.

scholarly journals Electrophysiological markers of cochlear function correlate with hearing-in-noise performance among audiometrically normal subjects

2020 ◽  
Vol 124 (2) ◽  
pp. 418-431
Author(s):  
Kelsie J. Grant ◽  
Anita M. Mepani ◽  
Peizhe Wu ◽  
Kenneth E. Hancock ◽  
Victor de Gruttola ◽  
...  
Keyword(s):  
Animal Studies ◽  
Recognition Performance ◽  
Normal Subjects ◽  
Cochlear Function ◽  
Neural Connections ◽  
Hearing Sensitivity ◽  
Neural Damage ◽  
Hearing In Noise ◽  
Age Related ◽  
Electrophysiological Responses

Recent animal studies suggest that millions of people may be at risk of permanent impairment from cochlear synaptopathy, the age-related and noise-induced degeneration of neural connections in the inner ear that “hides” behind a normal audiogram. This study examines electrophysiological responses to clicks in a large cohort of subjects with normal hearing sensitivity. The resultant correlations with word recognition performance are consistent with an important contribution cochlear neural damage to deficits in hearing in noise abilities.

Hearing Loss- and Hearing Aid-Related Stigma

2002 ◽  
Vol 11 (2) ◽  
pp. 83-91 ◽  
Author(s):  
Susan F. Erler ◽  
Dean C. Garstecki
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Age Groups ◽  
Impaired Hearing ◽  
Younger Women ◽  
Normal Limits ◽  
Hearing Aid Use ◽  
Age Related ◽  
Women’S Perceptions

Impaired hearing and the use of hearing aids are often perceived negatively. Many adults deny hearing loss and reject amplification, in part due to such stigma. Women and men differ in how they age and adjust to impaired hearing, yet little is known specifically about women’s perceptions of stigma related to hearing loss and hearing aid use. The purpose of this study was to examine the degree of stigma associated with hearing loss and hearing aid use among women in three age groups (35–45 years, 55–65 years, and 75–85 years). Participants were 191 women with hearing within normal limits based on age-related norms. Using pairs of descriptors (i.e., semantic differentials), participants completed statements related to hearing loss and hearing aid use. Results suggest that negative perceptions associated with hearing loss and hearing aid use are affected by age. Younger women perceive greater stigma than older women. Less stigma is associated with hearing aid use than hearing loss, suggesting a positive effect of hearing loss management. Implications for clinical practice and marketing of hearing instruments are discussed.

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