Posts Tagged ‘aging’
Posted by Callier Library on November 19, 2009
The auditory system is capable of perceptually restoring inaudible portions of speech. This restoration may be compromised as a result of hearing impairment, particularly if it is combined with advanced age, because of degradations in the bottom-up and top-down processes. To test this hypothesis, phonemic restoration was quantitatively measured with hearing-impaired listeners of varying ages and degrees of hearing impairment, as well as with a normal-hearing control group. The results showed that the restoration benefit was negatively correlated with both hearing impairment and age, supporting the original hypothesis. Group data showed that listeners with mild hearing loss were able to perceptually restore the missing speech segments as well as listeners in the normal-hearing group. By contrast, the moderately-impaired group showed no evidence of perceptual restoration. Further analysis using the articulation index showed that listeners with mild hearing loss were able to restore speech better as the audibility improved. Moderately-impaired listeners, on the other hand, were unable to do so, even when the articulation index was high. The overall findings suggest that, in addition to insufficient audibility, degradations in the bottom-up and/or top-down mechanisms as a result of hearing loss may limit or entirely prevent phonemic restoration.
from Hearing Research
Posted in Research | Tagged: aging, auditory scene analysis, bottom-up processing, hearing impairment, Phonemic restoration, top-down processing | Leave a Comment »
Posted by Callier Library on November 19, 2009
The auditory system is capable of perceptually restoring inaudible portions of speech. This restoration may be compromised as a result of hearing impairment, particularly if it is combined with advanced age, because of degradations in the bottom-up and top-down processes. To test this hypothesis, phonemic restoration was quantitatively measured with hearing-impaired listeners of varying ages and degrees of hearing impairment, as well as with a normal-hearing control group. The results showed that the restoration benefit was negatively correlated with both hearing impairment and age, supporting the original hypothesis. Group data showed that listeners with mild hearing loss were able to perceptually restore the missing speech segments as well as listeners in the normal-hearing group. By contrast, the moderately-impaired group showed no evidence of perceptual restoration. Further analysis using the articulation index showed that listeners with mild hearing loss were able to restore speech better as the audibility improved. Moderately-impaired listeners, on the other hand, were unable to do so, even when the articulation index was high. The overall findings suggest that, in addition to insufficient audibility, degradations in the bottom-up and/or top-down mechanisms as a result of hearing loss may limit or entirely prevent phonemic restoration.
from Hearing Research
Posted in Research | Tagged: aging, auditory scene analysis, bottom-up processing, hearing impairment, Phonemic restoration, top-down processing | Leave a Comment »
Posted by Callier Library on October 30, 2009
Spiral ganglion neurons (SGNs) are the relay station for auditory information between hair cells and central nervous system. Age-related decline of auditory function due to SGN loss can not be ameliorated by hearing aids or cochlear implants. Recent findings clearly indicate that survival of SGNs during aging depends on genetic and environmental interactions, which can be demonstrated at the systemic, tissue, cellular, and molecular levels. At the systemic level, both insulin/insulin-like growth factor-1 and lipophilic/steroid hormone pathways influence SGN survival during aging. At the level of organ of the Corti, it is difficult to determine whether age-related SGN loss is primary or secondary degeneration. However, a late stage of SGN degeneration may be independent of age-related loss of hair cells. At the cellular and molecular level, several pathways, particularly free radical and calcium signaling pathways, can influence age-related SGN loss, and further studies should determine how these pathways contribute to SGN loss, such as whether they directly or indirectly act on SGNs. With the advancement of recent genetic and pharmacologic tools, we should not only understand how SGNs die during aging, but also find ways to delay this loss.
from Hearing Research
Posted in Research | Tagged: aging, calcium, caloric restriction, glucocorticoid, hair cell, neural presbycusis, Spiral ganglion neuron | Leave a Comment »
Posted by Callier Library on October 28, 2009
The purpose of this study was to determine the 10-yr cumulative incidence of hearing impairment and associations of education, occupation and noise exposure history with the incidence of hearing impairment in a population-based cohort study of 3753 adults ages 48-92 years at the baseline examinations during 1993-1995 in Beaver Dam, WI. Hearing thresholds were measured at baseline, 2.5 yr, 5 yr, and 10-yr follow-up examinations. Hearing impairment was defined as a pure-tone average (PTA) > 25 dB HL at 500, 1000, 2000, and 4000 Hz. Demographic characteristics and occupational histories were obtained by questionnaire. The 10-yr cumulative incidence of hearing impairment was 37.2%. Age (5 yr; Hazard Ratio (HR)=1.81), sex (M v W; HR=2.29), occupation based on longest held job (Production/Operations/Farming vs others; HR=1.34), marital status (unmarried vs married; HR=1.29) and education (<16 vs 16+ yrs; HR=1.40) were associated with the 10 yr incidence. History of noisy jobs was not associated with the 10-yr incidence of hearing impairment. The risk of hearing impairment was high, with women experiencing a slightly later onset. Markers of socioeconomic status were associated with hearing impairment, suggesting that hearing impairment in older adults may be associated with modifiable lifestyle and environmental factors, and therefore, at least partially preventable.
from Hearing Research
Posted in Research | Tagged: aging, hearing impairment, hearing loss, Incidence, presbyacusis, socioeconomic status | Leave a Comment »
Posted by Callier Library on October 9, 2009
Human behavioral data indicate that older adults are slower to perform lexical decisions (LDs) than young adults but show similar reaction time gains when these decisions are primed semantically. The present study explored the functional neuroanatomic bases of these frequently observed behavioral findings. Young and older groups completed unprimed and primed LD tasks while functional magnetic resonance imaging (fMRI) was recorded, using a fully randomized trial design paralleling those used in behavioral research. Results from the unprimed task found that age-related slowing of LD was associated with decreased activation in perceptual extrastriate regions and increased activation in regions associated with higher level linguistic processes, including prefrontal cortex. In contrast to these age-related changes in brain activation, the older group showed a preserved pattern of fMRI decreases in inferior temporal cortex when LD was primed semantically. These findings provide evidence that older adults’ LD abilities benefit from contexts that reduce the need for frontally mediated strategic processes and capitalize on the continued sensitivity of inferior temporal cortex to automatic semantic processes in aging.
from Cerebral Cortex
Posted in Research | Tagged: aging, fMRI, lexical decision, prefrontal cortex, priming, reaction time | Leave a Comment »
Posted by Callier Library on October 7, 2009
Autobiographical memory (AM) is built up from various kinds of knowledge, from general to specific, via generative processes. Aging seems to particularly affect the episodic autobiographical information while preserving information that is more semantic. However, the mechanism of this deficit has not yet been thoroughly tested in relation to working memory. This study is designed to investigate, in a group of 100 subjects, the relationships between age, accessibility to different levels of AM specificity, and two main components of working memory: the central executive and the episodic buffer. We used a new task composed of four embedded verbal autobiographical fluencies (VAF) – from low to highest specificity levels – exploring lifetime periods, general events, specific events, and details, plus tasks exploring free recall of episodic AM and updating, shifting, inhibition, and feature binding in working memory. The results demonstrate that age-related difficulties increase with level of specificity of autobiographical knowledge, i.e., from semantic to episodic aspects. Moreover, regression analyses show that increase in age-related deficit with level of specificity of AM is largely mediated by performance on executive functions (updating and inhibition) and to a lesser extent feature binding in working memory. The results confirm in episodic AM the executive/working memory aging hypothesis, and for the first time highlight the role of episodic buffer in associating the various different details of specific events that elicit the conscious recollection.
from Neuropsychologia
Posted in Research | Tagged: aging, working memory, executive functions, recollection, Episodic memory, Autobiographical memory, Binding, Episodic Buffer | Leave a Comment »
Posted by Callier Library on October 7, 2009
Differences in gap detection for younger and older adults have been shown to vary with the complexity of the task or stimuli, but the factors that contribute to these differences remain unknown. To address this question, we examined the extent to which age-related differences in processing speed and workload predicted age-related differences in gap detection. Gap detection thresholds were measured for 10 younger and 11 older adults in two conditions that varied in task complexity but used identical stimuli: (1) gap location fixed at the beginning, middle, or end of a noise burst and (2) gap location varied randomly from trial to trial from the beginning, middle, or end of the noise. We hypothesized that gap location uncertainty would place increased demands on cognitive and attentional resources and result in significantly higher gap detection thresholds for older but not younger adults. Overall, gap detection thresholds were lower for the middle location as compared to beginning and end locations and were lower for the fixed than the random condition. In general, larger age-related differences in gap detection were observed for more challenging conditions. That is, gap detection thresholds for older adults were significantly larger for the random condition than for the fixed condition when the gap was at the beginning and end locations but not the middle. In contrast, gap detection thresholds for younger adults were not significantly different for the random and fixed condition at any location. Subjective ratings of workload indicated that older adults found the gap-detection task more mentally demanding than younger adults. Consistent with these findings, results of the Purdue Pegboard and Connections tests revealed age-related slowing of processing speed. Moreover, age group differences in workload and processing speed predicted gap detection in younger and older adults when gap location varied from trial to trial; these associations were not observed when gap location remained constant across trials. Taken together, these results suggest that age-related differences in complex measures of auditory temporal processing may be explained, in part, by age-related deficits in processing speed and attention.
from Hearing Research
Posted in Research | Tagged: aging, auditory temporal processing, Cognitive, gap detection, processing speed, workload | Leave a Comment »
Posted by Callier Library on September 30, 2009
Psychophysical data on hearing sensitivity and various measures of supra-threshold auditory temporal processing are presented for large groups of young (18-35 y), middle-aged (40-55 y) and older (60-89 y) adults. Hearing thresholds were measured at 500, 1414 and 4000 Hz. Measures of temporal processing included gap-detection thresholds for bands of noise centered at 1000 and 3500 Hz, stimulus onset asynchronies for monaural and dichotic temporal-order identification for brief vowels, and stimulus onset/offset asynchronies for the monaural temporal masking of vowel identification. For all temporal-processing measures, the impact of high-frequency hearing loss in older adults was minimized by a combination of low-pass filtering the stimuli and use of high presentation levels. The performance of the older adults was worse than that of the young adults on all measures except gap-detection threshold at 1000 Hz. Middle-aged adults performed significantly worse than the young adults on measures of threshold sensitivity and three of the four measures of temporal-order identification, but not for any of the measures of temporal masking. Individual differences are also examined among a group of 124 older adults. Cognition and age were found to be significant predictors, although only 10-27% of the variance could be accounted for by these predictors.
from Hearing Research
Posted in Research | Tagged: aging, hearing loss, Individual Differences, temporal processing | Leave a Comment »
Posted by Callier Library on September 30, 2009
This study examined the relationship that personal pronouns spoken during a marital conversation have with the emotional qualities of those interactions and with marital satisfaction. Middle-aged and older couples (N = 154) engaged in a 15-min conflict conversation during which physiology and emotional behavior were continuously monitored. Verbatim transcripts of the conversations were coded into 2 lexical categories: (a) we-ness (we-words), pronouns that focus on the couple; (b) separateness (me/you-words), pronouns that focus on the individual spouses. Analyses revealed that greater we-ness was associated with a number of desirable qualities of the interaction (lower cardiovascular arousal, more positive and less negative emotional behavior), whereas greater separateness was associated with a less desirable profile (more negative emotional behavior, lower marital satisfaction). In terms of age differences, older couples used more we-ness words than did middle-aged couples. Further, the associations between separateness and marital satisfaction were strongest for older wives. These findings indicate that the emotional aspects of marital quality are expressed in the natural language of couples engaged in conversation.
from Psychology and Aging
Posted in Research | Tagged: aging, emotion, marital satisfaction, personal pronouns, we-ness versus separateness | Leave a Comment »
Posted by Callier Library on September 30, 2009
A dual-task interference paradigm was used to investigate the effect of perceptual effort on recall of spoken word lists by young and older adults with good hearing and with mild-to-moderate hearing loss. In addition to poorer recall accuracy, listeners with hearing loss, especially older adults, showed larger secondary task costs while recalling the word lists even though the stimuli were presented at a sound intensity that allowed correct word identification. Findings support the hypothesis that extra effort at the sensory–perceptual level attendant to hearing loss has negative consequences to downstream recall, an effect that may be further magnified with increased age.
from Psychology and Aging
Posted in Research | Tagged: aging, dual task, hearing loss, memory, speech processing | Leave a Comment »
Posted by Callier Library on September 30, 2009
This study examined the relationship that personal pronouns spoken during a marital conversation have with the emotional qualities of those interactions and with marital satisfaction. Middle-aged and older couples (N = 154) engaged in a 15-min conflict conversation during which physiology and emotional behavior were continuously monitored. Verbatim transcripts of the conversations were coded into 2 lexical categories: (a) we-ness (we-words), pronouns that focus on the couple; (b) separateness (me/you-words), pronouns that focus on the individual spouses. Analyses revealed that greater we-ness was associated with a number of desirable qualities of the interaction (lower cardiovascular arousal, more positive and less negative emotional behavior), whereas greater separateness was associated with a less desirable profile (more negative emotional behavior, lower marital satisfaction). In terms of age differences, older couples used more we-ness words than did middle-aged couples. Further, the associations between separateness and marital satisfaction were strongest for older wives. These findings indicate that the emotional aspects of marital quality are expressed in the natural language of couples engaged in conversation.
from Psychology and Aging
Posted in Research | Tagged: aging, emotion, marital satisfaction, personal pronouns, we-ness versus separateness | Leave a Comment »
Posted by Callier Library on September 30, 2009
This study examined the relationship that personal pronouns spoken during a marital conversation have with the emotional qualities of those interactions and with marital satisfaction. Middle-aged and older couples (N = 154) engaged in a 15-min conflict conversation during which physiology and emotional behavior were continuously monitored. Verbatim transcripts of the conversations were coded into 2 lexical categories: (a) we-ness (we-words), pronouns that focus on the couple; (b) separateness (me/you-words), pronouns that focus on the individual spouses. Analyses revealed that greater we-ness was associated with a number of desirable qualities of the interaction (lower cardiovascular arousal, more positive and less negative emotional behavior), whereas greater separateness was associated with a less desirable profile (more negative emotional behavior, lower marital satisfaction). In terms of age differences, older couples used more we-ness words than did middle-aged couples. Further, the associations between separateness and marital satisfaction were strongest for older wives. These findings indicate that the emotional aspects of marital quality are expressed in the natural language of couples engaged in conversation.
from Psychology and Aging
Posted in Research | Tagged: aging, emotion, marital satisfaction, personal pronouns, we-ness versus separateness | Leave a Comment »
Posted by Callier Library on September 29, 2009
Purpose: The purpose of this study was to explore the nature and extent of variability in tongue movement during healthy swallowing as a function of aging and gender. In addition, changes were quantified in healthy tongue movements in response to specific differences in the nature of the swallowing task (discrete vs. sequential swallows).
Method: Electromagnetic midsagittal articulography (EMMA) was used to study the swallowing-related movements of markers located in midline on the anterior (blade), middle (body), and posterior (dorsum) tongue in a sample of 34 healthy adults in 2 age groups (under vs. over 50 years of age). Participants performed a series of reiterated water swallows, in either a discrete or a sequential manner.
Results: This study shows that age-related changes in tongue movements during swallowing are restricted to the domain of movement duration. The authors confirm that different tongue regions can be selectively modulated during swallowing tasks and that both functional and anatomical constraints influence the manner in which tongue movement modulation occurs. Sequential swallowing, in comparison to discrete swallowing, elicits simplification or down-scaling of several kinematic parameters.
Conclusion: The data illustrate task-specific stereotyped patterns of tongue movement in swallowing, which are robust to the effects of healthy aging in all aspects other than movement duration.
from the Journal of Speech, Language, and Hearing Research
Posted in Research | Tagged: aging, dysphagia, electromagnetic articulography, kinematics, swallowing, tongue | Leave a Comment »
Posted by Callier Library on September 23, 2009
The present study examined age differences in neural lateralization patterns during swallowing and three related tasks, using functional magnetic resonance imaging (fMRI). Ten healthy right-handed young adults (mean age = 21.7 years, SD = 2.1 years) and nine healthy elders (mean age = 70.2 years, SD = 3.9 years) were scanned in a 3-T MRI head scanner. Participants were visually cued to “prepare to swallow,” “swallow,” “tap your tongue,” and “clear your throat” in randomized order. Laterality preference for each task was examined within and between groups using region-of-interest (ROI) analyses in seven areas of the left and right primary sensorimotor and premotor cortices. Results of the within-group comparisons verified a more active role of the left premotor cortex in motor-cognitive planning of deglutition in both young and older adults and a more active role of selected areas of the right hemisphere during swallowing in young adults. Greater variability was seen during tongue tapping and throat clearing in both groups. Finally, as people age the cortical hemispheric control of swallowing seems to start becoming more symmetrical/bilateral, which may indicate neural compensatory mechanisms of the aging brain commonly seen for other motor and cognitive functions.
from Dysphagia
Posted in Research | Tagged: neurophysiology, swallowing, deglutition, aging, neuroimaging, fMRI, deglutition disorders, lateralization | Leave a Comment »
Posted by Callier Library on August 26, 2009
We describe the development of a 35-item, oral word-reading test with two equivalent forms (HART-A and HART-B) designed to estimate premorbid abilities. Both forms show excellent internal consistency (coefficients alpha >.91) and test-retest reliability (Pearson rs >.90). HART performance was combined with demographic variables to generate regression equations that predict IQ scores obtained concurrently and 4-8 years earlier. The resulting models explained 61% of full scale IQ (FSIQ) variability in 327 healthy adults. The FSIQs that can be estimated range from below 73 to above 131. Combined with demographic variables, these two brief word reading tests accurately predict a broader range of IQs than Blair and Spreen’s (1989) longer version. Equivalent forms make it especially useful for longitudinal studies.
from
Posted in Research | Tagged: aging, Cognitive disorders, intelligence, Keywords: Neuropsychology, Premorbid IQ | Leave a Comment »