Age-Associated Reduction of Asymmetry in Human Central Auditory Function: A 1H-Magnetic Resonance Spectroscopy Study

Chen, Xianming; Liang, Yan; Deng, Yuru; Li, Jianzhong; Chen, Shiyan; Wang, Cuixia; Luo, Peng

doi:10.1155/2013/735290

Cited by 14 publications

(14 citation statements)

References 25 publications

(22 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Profant et al (2015) did not observe a significant effect of age on GABA levels in auditory cortex. In contrast, Chen et al (2013) did report a significant decline in GABA levels: in the right (but not the left) hemisphere before pure tone stimulation, and in both hemispheres after stimulation. Likewise, Gao et al (2015) reported that older adults suffering from age-related hearing loss exhibited lower GABA levels in auditory cortex compared to other older adults.…”

Section: Age-related Decline In Gaba Levelscontrasting

confidence: 62%

“…Most previous neural dedifferentiation studies have been focused on the visual cortex, and so it remains unclear whether dedifferentiation also occurs in other sensory regions, such as the auditory cortex. Furthermore, the results of the small number of human studies investigating age-related changes in GABA levels in the auditory cortex are mixed (20,21). In the present study, we therefore asked whether older adults would have reduced distinctiveness and reduced GABA levels in the auditory cortex compared with young adults.…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Lalwani

Gagnon

Cassady

et al. 2018

Preprint

View full text Add to dashboard Cite

Neural activation patterns in the ventral visual cortex in response to different categories of visual stimuli (e.g., faces vs. houses) are less selective, or distinctive, in older adults than in younger adults, a phenomenon known as age-related neural dedifferentiation. Previous work in animals suggests that age-related reductions of the inhibitory neurotransmitter, gamma aminobutyric acid (GABA), may play a role in this age-related decline in neural distinctiveness.In this study, we investigated whether neural dedifferentiation extends to auditory cortex and whether individual differences in GABA are associated with individual differences in neural distinctiveness in humans. 20 healthy young adults (ages 18-29) and 23 healthy older adults (over 65) completed a functional magnetic resonance imaging (fMRI) scan, during which neural activity was estimated while they listened to foreign speech and music. GABA levels in the auditory, ventrovisual and sensorimotor cortex were estimated in the same individuals in a separate magnetic resonance spectroscopy (MRS) scan. Relative to the younger adults, the older adults exhibited both (1) less distinct activation patterns for music vs. speech stimuli and (2) lower GABA levels in the auditory cortex. Also, individual differences in auditory GABA levels (but not ventrovisual or sensorimotor GABA levels) predicted individual differences in neural distinctiveness in the auditory cortex in the older adults. These results demonstrate that agerelated neural dedifferentiation extends to the auditory cortex and suggest that declining GABA levels may play a role in neural dedifferentiation in older adults. Significance StatementPrior work has revealed age-related neural dedifferentiation in the visual cortex. GABA levels also decline with age in several parts of the human cortex. Here, we report that these two agerelated changes are linked; neural dedifferentiation is associated with lower GABA levels in older adults. We also show that age-related neural dedifferentiation extends to auditory cortex, suggesting that it may be a general feature of the aging brain. These findings provide novel insights into the neurochemical basis of age-related neural dedifferentiation in humans and also offer a potential new avenue for investigating age-related declines in central auditory processing.

show abstract

Section: Age-related Decline In Gaba Levelscontrasting

confidence: 62%

Section: Introductionmentioning

confidence: 93%

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Lalwani

Gagnon

Cassady

et al. 2018

Preprint

View full text Add to dashboard Cite

show abstract

“…An alternative explanation for age-related differences in hemispheric asymmetry has been offered by Chen et al ( 2013 ). In this study, young (18–27 years) and older adults (55–75 years) with clinically normal hearing underwent magnetic resonance spectroscopy scans in order to investigate hemispheric contents of glutamate and GABA, two neurotransmitters that mediate excitatory and inhibitory processes.…”

Section: Discussionmentioning

confidence: 99%

“…As such, the NAA percentage is used to evaluate neuronal damage or loss. Spectroscopic investigations have demonstrated that NAA concentrations in the temporal-auditory brain regions decrease with advancing age, reflecting neuronal dysfunction and/or loss in the aging brain (Angelie et al, 2001 ; Chen et al, 2013 ). This NAA observation is consistent with imaging studies demonstrating an age-related reduction in brain volume (e.g., Matsumae et al, 1996 ; Lim and Spielman, 1997 ).…”

Section: Discussionmentioning

confidence: 99%

Aging Affects Neural Synchronization to Speech-Related Acoustic Modulations

Goossens

Vercammen

Wouters

et al. 2016

Front. Aging Neurosci.

View full text Add to dashboard Cite

As people age, speech perception problems become highly prevalent, especially in noisy situations. In addition to peripheral hearing and cognition, temporal processing plays a key role in speech perception. Temporal processing of speech features is mediated by synchronized activity of neural oscillations in the central auditory system. Previous studies indicate that both the degree and hemispheric lateralization of synchronized neural activity relate to speech perception performance. Based on these results, we hypothesize that impaired speech perception in older persons may, in part, originate from deviances in neural synchronization. In this study, auditory steady-state responses that reflect synchronized activity of theta, beta, low and high gamma oscillations (i.e., 4, 20, 40, and 80 Hz ASSR, respectively) were recorded in young, middle-aged, and older persons. As all participants had normal audiometric thresholds and were screened for (mild) cognitive impairment, differences in synchronized neural activity across the three age groups were likely to be attributed to age. Our data yield novel findings regarding theta and high gamma oscillations in the aging auditory system. At an older age, synchronized activity of theta oscillations is increased, whereas high gamma synchronization is decreased. In contrast to young persons who exhibit a right hemispheric dominance for processing of high gamma range modulations, older adults show a symmetrical processing pattern. These age-related changes in neural synchronization may very well underlie the speech perception problems in aging persons.

show abstract

“…Specifically, asymmetry between the two ear test results increases as the corpus callosum atrophies increase in the isthmus and splenium regions during the aging [8]. However findings from a large number of dichotic listening tests indicate that asymmetry of speech processing increases in elderly people, regardless of hearing loss [4,8,9]. Dichotic ability can be evaluated using several tests of central auditory system that involve listening to competing signals challenging the auditory system and cognitive function.…”

Section: Introductionmentioning

confidence: 99%

Evaluating the effectiveness of dichotic training in the elderly adults: a single subject study

Shahidipour

Farahani

Mohammadkhani

et al. 2021

AVR

View full text Add to dashboard Cite

Background and Aim: Elderly people usually show poor performance in dichotic listening tasks. In this condition, the left ear being often the weaker one shows a performance below the normal limits. Studies have shown the effectiveness of dichotic listening training in auditory and language processing for adults and children with neurological disorders. This study aimed to develop a home-version of dichotic training and investigate its effectiveness in elderly adults. Methods: Participants in this single-subject interventional study (AB design) were four elderly subjects (two males and two females) aged 65−75 years. The main inclusion criteria were dichotic listening deficit demonstrated by the dichotic digit test (DDT), no neurological or cognitive disorders, and normal hearing threshold. Dichotic listening training was performed with an informal home-version of dichotic interaural intensity difference (DIID) training program for seven weeks. DDT was performed seven consecutive weeks before (phase A) and after the intervention (phase B) at the end of each week. Results: Data were analyzed by single-subject study statistics. Findings demonstrated an improvement in DDT scores for the left ear and decrease in right ear advantage scores in all the elderly adults after DIID training program. It seems that this training program could remediate poor performance in dichotic listening tasks in elderly people. Conclusion: The advantage of this method is that it can be easily done at home and is costeffective. However, further studies are needed to approve the neuroplasticity and structural changes in the brain after the DIID training program in this population. Keywords: Auditory rehabilitation; dichotic training; dichotic listening; elderly; singlesubject study

show abstract

Age-Associated Reduction of Asymmetry in Human Central Auditory Function: A 1H-Magnetic Resonance Spectroscopy Study

Cited by 14 publications

References 25 publications

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Aging Affects Neural Synchronization to Speech-Related Acoustic Modulations

Evaluating the effectiveness of dichotic training in the elderly adults: a single subject study

Contact Info

Product

Resources

About