CDA
Cytidine deaminase (EC 3.5.4.5) (Cytidine aminohydrolase) [CDD]
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This study provides a cross-national perspective to apply Cumulative Dis/Advantage (CDA) in explaining health inequality between developing and developed countries in the context of Welfare State Theory. Cross-sectional data from the international Health Retirement Study (United States, China, Mexico, and England) in 2013-2014 were used ([i]n[/i] = 97,978). Four health indicators were included: self-reported health, depressive symptoms, functional ability, and memory. Regression models were fitted to examine the moderation roles of country and gender. Results indicated older Chinese and Mexican had poorer health status than their British and American counterparts consistently except for Mexicans' memory. Cumulative health gaps between developing and developed countries existed only for functional ability. There is no evidence of a widening gap in health status between genders in late life. CDA explains the increasing gaps of functional ability across age groups between countries. General health and mental health, may however, depend more on individuals' intrinsic capacity and human agency.
MeSH Terms
- Aged
- Aged, 80 and over
- China
- Cross-Sectional Studies
- England
- Female
- Health Behavior
- Health Status Disparities
- Humans
- Longevity
- Male
- Mexico
- Middle Aged
- Regression Analysis
- Self Report
- Sex Factors
- Social Class
- Social Welfare
- United States
Keywords
- Cumulative dis/advantage
- cross-national study
- health retirement study
- welfare state theory
Similarity between targets and distracters is a key factor in generating distractibility, and exerts a large detrimental effect on aging. The present EEG study tested the role of a new stimulus dimension in generating distractibility in visual Working Memory (vWM), namely numerical similarity. In a change detection paradigm a varying number of relevant and irrelevant stimuli were presented simultaneously in opposite hemifields. Behavioral results indicated that young participants outperformed older individuals; however, in both groups numerical similarity per se did not modulate performance. At the electrophysiological level, in young participants the Contralateral Delay Activity (CDA, a proxy for item maintenance in vWM) was modulated by the numerosity of the relevant items regardless of numerical similarity. In older participants, the CDA was modulated by target numerosity only in the same numerical condition, where the total number of (relevant and irrelevant) items increased with increasing target numerosities. No effect was present in the dissimilar numerical condition, where the total number of items did not vary substantially across target numerosity. This pattern was suggestive of an age-related effect of the total number of (relevant and irrelevant) items on vWM. The additional analyses on alpha-band lateralization measures support this interpretation by revealing that older adults lacked selective deployment of attentional and vWM resources towards the relevant hemifield. Overall, the results indicate that, while numerical similarity does not modulate distractibility, there is an age-related redistribution of vWM resources across the two visual fields, ultimately leading to a general decrease in task performance of older adults.
MeSH Terms
- Adult
- Aged
- Aging
- Alpha Rhythm
- Attention
- Evoked Potentials
- Female
- Healthy Volunteers
- Humans
- Male
- Memory, Short-Term
- Young Adult
Working memory updating (updating) and working memory capacity (WMC) have been assumed to share a common mechanism. However, it is unclear whether WMC can be expanded by boosting the efficiency of updating, particularly during late adulthood. In this randomized controlled study, 33 older adults (aged 60 years and above, M = 69.53, SD = 5.21) were assigned to updating training (n = 17) and contact control (n = 16) groups. In the training group, updating was targeted by a running memory task and a chess game in each training session; whereas in the control group, motivational effects were estimated by their attendance to a series of mental health-related lectures. The boosted updating efficiency was demonstrated by direct training gains over sessions on updating criterion/training tasks, and significant frontocentral inflation at the N2 time range. Near transfer effects were revealed on untrained similar measures immediately after training and partly maintained at a 3-month follow-up. Far transfer effects to WMC were revealed by a significant increase in contralateral delay activity (CDA) ERP measures, although these effects did not manifest on WMC span tasks and other far transfer measures. Note that increased CDA was significantly correlated with the extent of direct gains in updating training. Our findings suggest that updating efficiency can be boosted in older adults; although it has not yet brought about an explicit expansion of WMC in our behavioral measures (i.e., on span tasks), capacity-related neural changes (i.e., on CDA) have nevertheless, started to show up in our short-term updating training program. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
MeSH Terms
- Aged
- Aging
- Female
- Humans
- Male
- Memory, Short-Term
- Middle Aged
Negative affect (NA) has been related to lower working memory performance across all ages, including in older adults where it has been suggested as a marker for later cognitive impairments. However, NA-related decreases in working memory performance have not been shown in a full range of working memory paradigms or fully explored in the context of electrophysiological measures of working memory. We examined the impact of NA and related markers on an electroencephalography (EEG) marker of visual working memory (VWM) capacity, referred to as the contralateral delay activity (CDA). This study analyzed data collected from 48 cognitively intact, mildly stressed older adults (50-74 years old) who completed a VWM change-detection task to elicit the CDA, as well as self-rated measures of affect, stress, neuroticism and depression. Regression analyses revealed significant CDA amplitude effects with NA across task conditions. These results indicate a reduction in a physiological measure of VWM capacity in high-NA participants. These results are of interest as NA has been associated with a greater risk for worse cognitive function, detrimental health outcomes and reduced quality of life in older adults. This research adds to our understanding of how NA impacts older adults and gives a potential biomarker for successful intervention outcomes.
Keywords
- EEG
- aging
- contralateral delay activity
- event-related potentials
- memory
- negative affect
- visual working memory
Visual short-term memory (vSTM) is a cognitive resource that declines with age. This study investigated whether electroencephalography (EEG) correlates of vSTM vary with cognitive development over individuals' lifespan. We measured vSTM performance and EEG in a lateralized whole-report task in a healthy birth cohort, whose cognitive function (intelligence quotient) was assessed in youth and late-middle age. Higher vSTM capacity (K; measured by Bundesen's theory of visual attention) was associated with higher amplitudes of the contralateral delay activity (CDA) and the central positivity (CP). In addition, rightward hemifield asymmetry of vSTM (K ) was associated with lower CDA amplitudes. Furthermore, more severe cognitive decline from young adulthood to late-middle age predicted higher CDA amplitudes, and the relationship between K and the CDA was less reliable in individuals who show higher levels of cognitive decline compared to individuals with preserved abilities. By contrast, there was no significant effect of lifespan cognitive changes on the CP or the relationship between behavioral measures of vSTM and the CP. Neither the CDA, nor the CP, nor the relationships between K or K and the event-related potentials were predicted by individuals' current cognitive status. Together, our findings indicate complex age-related changes in processes underlying behavioral and EEG measures of vSTM and suggest that the K-CDA relationship might be a marker of cognitive lifespan trajectories.
MeSH Terms
- Adult
- Attention
- Cognition
- Cognitive Aging
- Cognitive Dysfunction
- Cohort Studies
- Electroencephalography
- Healthy Aging
- Humans
- Male
- Memory, Short-Term
- Middle Aged
- Photic Stimulation
- Reaction Time
- Visual Perception
- Young Adult
Keywords
- Contralateral delay activity
- Electroencephalography
- Healthy aging
- Lifespan cognitive development
- Visual short-term memory
The objective of this study was to develop a simple tool for the assessment of possible dental treatment needs (DTN) for non-dental professionals (Mini Dental Assessment, MDA). To keep the assessment universal, we aimed to base it on the patient's history and a simple chewing efficiency test (CET) as the dental status is a known determinant for chewing efficiency. The assessment was developed using data from 169 patients from two sites (University Hospital Giessen, St. Bonifatius Hospital Lingen, both Germany). In all patients, a dental examination was performed, the denture status was evaluated (based on the California Dental Association criteria; CDA criteria), and the DTN was determined. In addition, the time since the patient's last visit to a dentist (TLVD) and denture age (DA) were assessed. Furthermore, a CET was carried out and the comminution score was determined (CETS). In total, 108 patients required dental treatment. The mean value (±SD) was 2.9 ± 0.9 score points for the DTN, 2.5 ± 3.8 years for the TLVD, and 10.8 ± 8.9 years for the DA. There was a significant correlation (Spearman, P < .05) between the DTN and degree of comminution (3.4 ± 1.8). Based on the results of the statistical analysis, the intended assessment tool was developed using the variables CETS, TLVD, and DA weighed by their respective regression coefficients (10:3:1). Subsequently, the resulting MDA score (51.32 ± 28.14) was calculated. A sensitivity/specificity analysis was conducted and a receiver operating characteristic curve was calculated (SPSS 17.0, area under curve 0.805; 95 % CI 0.738-0.873). It can be concluded that the dental status of elderly patients is reflected in the outcome of the MDA. However, ongoing validation is needed. DRKS00003219.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Dental Care
- Female
- Geriatric Assessment
- Germany
- Health Services Needs and Demand
- Humans
- Male
- Mastication
- Middle Aged
- Sensitivity and Specificity
Keywords
- Clinical studies/trials
- Decision-making
- Diagnostic systems, gerontology
- Geriatric dentistry
To understand the nature of age-related changes in enumeration abilities we measured two ERP responses -N2pc and CDA, associated respectively to attentive individuation and VWM- and posterior alpha band (8-15 Hz) event-related desynchronization (ERD), traditionally linked to enhanced target processing. Two groups of old and young participants enumerated a variable number (1-6) of targets presented among distractors. Older participants were less accurate in enumerating targets. ERP results in old participants showed a suppression of N2pc amplitudes for all numerosities, and a decrease in CDA only for the largest set (4-6 targets). In contrast with the pattern for young adults, time/frequency results on older adults revealed neither a modulation of alpha oscillations as a function of target numerosity, nor an effect of ERD lateralization. These patterns indicate that both attention and working memory contribute to the age-related decline in enumeration, and point to an overall decrease in the activity of the visual areas responsible for the processing of the hemifield where the relevant objects are presented.
MeSH Terms
- Aged
- Aging
- Alpha Rhythm
- Attention
- Electroencephalography
- Electrophysiological Phenomena
- Evoked Potentials, Visual
- Female
- Humans
- Male
- Mathematical Concepts
- Memory, Short-Term
- Pattern Recognition, Visual
- Photic Stimulation
- Visual Perception
- Young Adult
Visual working memory (VWM) capacity is reduced in older adults. Research has shown age-related impairments to VWM encoding, but aging is likely to affect multiple stages of VWM. In the present study, we recorded the event-related potentials (ERPs) of younger and older adults during VWM maintenance and retrieval. We measured encoding-stage processing with the P1 component, maintenance-stage processing with the contralateral delay activity (CDA), and retrieval-stage processing by comparing the activity for old and new items (old-new effect). Older adults showed lower behavioral capacity estimates (K) than did younger adults, but surprisingly, their P1 components and CDAs were comparable to those of younger adults. This remarkable dissociation between neural activity and behavior in the older adults indicated that the P1 and CDA did not accurately assess their VWM capacity. However, the neural activity evoked during VWM retrieval yielded results that helped clarify the age-related differences. During retrieval, younger adults showed early old-new effects in frontal and occipital areas and a late central-parietal old-new effect, whereas older adults showed a late right-lateralized parietal old-new effect. The younger adults' early old-new effects strongly resembled an index of perceptual fluency, suggesting that perceptual implicit memory was activated. The activation of implicit memory could have facilitated the younger adults' behavior, and the lack of these early effects in older adults may suggest that they have much lower-resolution memory than do younger adults. From these data, we speculated that younger and older adults store the same number of items in VWM, but that younger adults store a higher-resolution representation than do older adults.
MeSH Terms
- Aged
- Aging
- Analysis of Variance
- Electroencephalography
- Evoked Potentials
- Female
- Functional Laterality
- Humans
- Male
- Memory, Short-Term
- Photic Stimulation
- Psychomotor Performance
- Visual Perception
- Young Adult
Behavioral evidence from the young suggests spatial cues that orient attention toward task-relevant items in visual working memory (VWM) enhance memory capacity. Whether older adults can also use retrospective cues ("retro-cues") to enhance VWM capacity is unknown. In the current event-related potential (ERP) study, young and old adults performed a VWM task in which spatially informative retro-cues were presented during maintenance. Young but not older adults' VWM capacity benefited from retro-cueing. The contralateral delay activity (CDA) ERP index of VWM maintenance was attenuated after the retro-cue, which effectively reduced the impact of memory load. CDA amplitudes were reduced prior to retro-cue onset in the old only. Despite a preserved ability to delete items from VWM, older adults may be less able to use retrospective attention to enhance memory capacity when expectancy of impending spatial cues disrupts effective VWM maintenance.
MeSH Terms
- Adolescent
- Aged
- Aging
- Attention
- Electroencephalography
- Evoked Potentials
- Female
- Humans
- Male
- Memory, Short-Term
- Middle Aged
- Neuropsychological Tests
- Visual Perception
- Young Adult
Estimates of working memory (WM) capacity increase in children, peak in young adulthood, and decline thereafter. Despite this symmetry, the mechanisms causing capacity increments in childhood may differ from those causing decline in old age. The contralateral delay activity (CDA) of the electroencephalogram, an event-related difference wave with a posterior scalp distribution, has been suggested as a neural marker of WM capacity. Here, we examine 22 children (10-12 years), 12 younger adults (20-25 years), and 22 older adults (70-75 years) in a cued change detection paradigm. Load levels and presentation times were varied within subjects. Behaviorally, we observed the expected life-span peak in younger adults and better performance with longer presentation times. With short presentation times, task load increased CDA amplitude and decreased behavioral performance in younger adults. Both effects were less pronounced in older adults. Children showed a unique pattern: Their behavioral load effects were as strong as those of younger adults, but their CDA was unaffected by load. With long presentation times, task load modulated the CDA in children and older adults but not in younger adults. These findings suggest that age-related differences in CDA reflect changes in the top-down control over WM representations.
MeSH Terms
- Aged
- Aging
- Brain
- Child
- Electroencephalography
- Evoked Potentials, Visual
- Functional Laterality
- Humans
- Memory, Short-Term
- Photic Stimulation
- Young Adult
CDA 1 is a novel antigen that within the brain is present specifically in neuronal growth cones. Electron microscope immunohistochemistry and subcellular fractionation showed the CDA 1 epitope to be on a cytosolic molecule. In cultured neurons, it is abundant in growth cones and not detectable in neurites or cell bodies. The development of the rat cerebral cortex was investigated by using the monoclonal antibody to CDA 1 and an antibody to SVP38, the synaptic vesicle glycoprotein. CDA 1 immunoreactivity in the rat cerebral cortex peaks just before birth and disappears by postnatal day 12, a few days before the major increase in the number of mature synapses. In contrast, SVP38 is expressed in parallel with the appearance of mature synapses. CDA 1 and SVP38 thus are markers of growth cones and synapses, respectively. Their expression during development reflects some of the structural and functional changes that occur during synapse formation.
MeSH Terms
- Aging
- Animals
- Cells, Cultured
- Cerebral Cortex
- Embryonic and Fetal Development
- Epitopes
- Membrane Glycoproteins
- Nerve Tissue Proteins
- Rats
- Rats, Inbred Strains
- Subcellular Fractions
- Synaptic Vesicles