Function Of Age Group Research Articles

Changes in the Networks of Attention across the Lifespan: A Graphical Meta-Analysis.

Three Posnerian networks of attention (alerting, orienting, and executive control) have been distinguished on the bases of behavioural, neuropsychological, and neuroscientific evidence. Here, we examined the trajectories of these networks throughout the human lifespan using the various Attention Network Tests (ANTs), which were specifically developed to measure the efficacy of these networks. The ANT Database was used to identify relevant research, resulting in the inclusion of 36 publications. We conducted a graphical meta-analysis using network scores from each study, based on reaction time plotted as a function of age group. Evaluation of attentional networks from childhood to early adulthood suggests that the alerting network develops relatively quickly, and reaches near-adult level by the age of 12. The developmental pattern of the orienting network seems to depend on the information value of the spatial cues. Executive control network scores show a consistent decrease (improvement) with age in childhood. During adulthood (ages 19-75), changes in alerting depend on the modality of the warning signal, while a moderate increase in orienting scores was seen with increasing age. Whereas executive control scores, as measured in reaction time, increase (deterioration) from young adulthood into later adulthood an opposite trend is seen when scores are based on error rates.

Pharmacodynamic Biomarkers in Infants with Hemophilia A Receiving Emicizumab in HAVEN 7

Background: Emicizumab, a bispecific antibody that mimics the cofactor function of activated factor (F)VIII, demonstrated a favorable safety and efficacy profile in infants with severe hemophilia A (HA) without FVIII inhibitors in HAVEN 7 (NCT04431726; Pipe et al. Blood 2022, 140[S1]: 457-459). It is known that some coagulation factors including FIX and FX, the binding targets of emicizumab, have lower plasma levels during the first 6 months of life. This research investigates whether the developing coagulation system impacts the pharmacodynamics (PD) of emicizumab prophylaxis in infants with HA enrolled to HAVEN 7 from birth to ≤ 12 months of age. Methods: Informed consent from the parents/legally authorized representative and ethics approval were obtained. PD was assessed by activated partial thromboplastin time (aPTT), FVIII activity using a chromogenic assay containing human FIX and FX (considered FVIII-like activity), and by FXIa-triggered thrombin generation (TG) assay. Plasma antigen levels of FIX and FX were determined using immunoassays. Plasma samples from 110 healthy infants (HIs; n=42, 0-3 months old; n=68, >3-24 months old) collected separately were also measured to generate age matched reference ranges. Results: In HAVEN 7, PD biomarkers, and FIX and FX plasma levels were assessed in 55 participants during the first 52 weeks of emicizumab exposure (data cut-off May 22, 2023). At baseline, mean FVIII activity was <1 IU/dL, mean TG peak height was zero, and aPTT was prolonged as expected due to the deficiency of FVIII. By the first post-baseline visit (Week 3), aPTT was normalized to the age matched reference range in most participants and was then generally maintained in the normal range throughout the treatment period. Mean (SD) FVIII-like activity increased to 22.52 (6.05) U/dL at Week 5 after the four loading doses of emicizumab and was sustained at 21-26 U/dL thereafter. Mean (SD) TG peak height increased to 67.37 (27.21) nM at Week 5 and was sustained at 67-88 nM throughout the treatment period. Mean plasma FIX and FX concentrations were not affected by emicizumab treatment. The PD biomarkers, and FIX and FX plasma levels were also analyzed as a function of age group. The loading period (first 4 weeks) was excluded and only “steady state” measurements were considered for the PD markers. All measurements were considered for FIX and FX plasma levels. Mean (SD) FVIII-like activity of 18.14 (5.40) U/dL in the youngest participants (1-2 months old) increased to 23.57 (7.64) U/dL at 3-4 months old and was similar (23-28 U/dL) in the older age groups. Age did not have a significant impact on mean TG peak height. There was no age effect on aPTT. Mean (SD) plasma FIX and FX antigen concentrations were 4.40 (1.09) µg/mL and 6.24 (1.29) µg/mL in the <1 month old participants, increased progressively with age until about 9 months old, and then stayed around 9-10 µg/mL for both FIX and FX. Lower plasma levels of FIX and FX, as well as FVIII activity were also observed in the HIs ≤3 months vs. >3 months of age. There was no significant difference in TG between ≤ 3 months vs. >3 months of age in HIs. FVIII-like activity increased with increasing emicizumab concentrations in a linear fashion up to emicizumab concentrations of 100 µg/mL. Hence, the lower FVIII-like activity in the youngest participants could be partially explained by lower mean “steady state” trough emicizumab concentrations of 48.3 µg/mL at 1 month of age, which then increased to approx. 60 µg/mL at 4-5 months of age and older. TG peak height increased with increasing emicizumab concentrations but showed large variability. Lower FIX and FX plasma levels during the first 9 months of age may also have an impact on the PD results. Even though the levels were lower in the youngest participants, increases in FVIII-like activity and TG were seen at “steady state” emicizumab in all age groups as expected based on previous studies of emicizumab. The sample sizes were small in some of the age groups analyzed. Conclusions: FVIII-like activity and thrombin generation increased, and aPTT was normalized after starting emicizumab prophylaxis in HAVEN 7. Increase with age was seen on FVIII-like activity as well as FIX and FX levels. The PD profiles of emicizumab in infants with HA were consistent with those previously observed in older children and adults with HA. Hence, even with lower levels of FIX and FX observed at the youngest participants, emicizumab showed the expected PD response.

Age-related variations in corneal stress-strain index in the Indian population.

To report age-related variations in corneal stress-strain index (SSI) in healthy Indians. It was a retrospective study where healthy Indian individuals aged between 11 and 70 years who had undergone corneal biomechanics assessment using Corvis ST between January 2017 and December 2021 were enrolled. Composite corneal biomechanical parameters and corneal SSI were abstracted from Corvis ST and compared across different age groups using one-way analysis of variance (ANOVA). Also, Pearson's correlation was used to evaluate the association between age and SSI. Nine hundred and thirty-six eyes of 936 patients with ages between 11 and 77 years with mean ± SD intraocular pressure (IOP) and pachymetry of 16.52 ± 2.10 mmHg and 541.13 ± 26.39 μs, respectively. Composite corneal biomechanical parameters such as deformation amplitude ratio max at 1 mm (P < 0.001) and 2 mm (P < 0.001), biomechanically corrected IOP (P = 0.004), stiffness parameter at A1 (P < 0.001, Corvis biomechanical index (P < 0.018), and SSI (P < 0.001) were found to be significantly different as a function of age group. We noted a statistically significant positive association of SSI with age (P < 0.001), spherical equivalent refractive error (P < 0.001), and IOP (P < 0.001) and a significant negative association with anterior corneal astigmatism (P < 0.001) and Anterior chamber depth (ACD) (P < 0.001). Also, SSI was positively associated with SPA1 and bIOP, whereas negatively associated with integrated radius, max inverse radius, and Max Deformation amplitude (DA) ratio at 1 mm and 2 mm. We noted a positive association of corneal SSI with age in normal healthy Indian eyes. This information could be helpful for future corneal biomechanical research.

Linguistic, affective, parental, and educational contributions to the bicultural identity development of Balkan minority adolescents.

This study investigated linguistic, affective, parental, and educational contributions to bicultural identity, in two samples of younger (13- to 14-year-old; N=95) and older (16- to 17-year-old; N=67) bilingual adolescents, who were immigrants or belonged to ethnic minority communities in the Balkans. While bicultural identity level was not differentiated as a function of age group, there was an age-related shift in its predictors. Bicultural identity level was significantly predicted by perceived educators' attitudes toward linguistic/cultural diversity in the younger adolescent group, but by personal affective states (motivation and attitudes) toward the mainstream language in the older adolescent group. Implications of the findings are discussed regarding educational and family practices that would facilitate biculturalism in minority adolescents.

Bone Mineral Density at Distal Forearm in Women in Mae Chaem District, Chiang Mai Province, Thailand: A Cross-Sectional Study

Background: Osteoporosis is a common health problem worldwide and has a high impact on quality of life and economic losses. However, having an early risk assessment can resolve the problem. Objective: To investigate the prevalence of bone mineral density (BMD) and osteoporosis in the distal forearm among Thai women in Mae Chaem District, Chiang Mai Province, Thailand. Methods: The subjects were 456 women, aged between 24-88 years who inhabit Mae Chaem District, Chiang Mai Province, Thailand. The demographic characteristics data was obtained by using self-administered questionnaires that determine common risk factors for osteoporosis. The BMD of the non-dominant distal forearm of all subjects was determined according to standard protocol by use of peripheral dual energy X-ray absorptiometry (pDEXA) scanning. Results: The BMD decreased as a function of age (Pearson's r = -0.645) while the BMD increased as a function of weight (Pearson's r = 0.389), and height (Pearson's r = 0.267). The percentage of prevalence is increased as a function of age-group in osteoporosis group, while it is decreased in that of normal bone density. In addition, the BMD at distal forearm decreased when the duration of menopause increased (Pearson's r = -0.455) Conclusion: The prevalence of osteoporosis was found in the women who reside in Mae Chaem District, Chiang Mai Province, Thailand. The current study will provide the information to guide the strategies for preventing osteoporosis in the population.

Sciences, Arts and Religions: The Triad in Action for Empathic Civilization in Bosnia and Herzegovina

BACKGROUND While many studies have investigated depression risk factors, few attempts have been made to weight, and compare them. Therefore, we conducted a prospective comparison of a sample of subjects suffering from major depressive disorder and a group of healthy subjects. We compared classic risk factors with internal elements such as personality, family dynamics and health locus of control. We also looked for prognostic factors. METHODS Forty people with major depressive disorder (the MDD group) were randomly assigned to different treatment groups and followed for two years. In parallel, we followed a group of 21 healthy subjects (healthy group). At the beginning of the study, sociodemographic data were recorded and all subjects were asked to complete the Multidimensional Health Locus of Control (MHLC) scale, the NEO Five-Factor Inventory (NEO-FFI), and the Family Adaptation and Cohesion Scale (FACES III). During the study, subjects were regularly assessed using the Hamilton Depression Scale (HDS) and the Short Form Health Survey (SF-12). RESULTS Of the 23 explanatory variables, 13 were statistically different (p≤0.05): age, gender, number of people living together, income, extravert personality and neuroticism, Internal HLC, Powerful others HLC, Adaptability of the current couple and the family of origin, and Cohesion of the ideal and nuclear family and family of origin. The accumulation of risk factors doubles the chances of suffering from MDD (odds ratio 1.905**). Independent of treatment, among the 13 variables, the first nine explain 34.1% of change in depression measured on the HDS scale (p<0.001). CONCLUSION While the size of our sample limits the robustness of our results, our study suggests that some risk factors are also prognostic. The respective weights of these factors vary as a function of age group. Finally, some, such as health locus of control, family dynamics or extraversion, can be modified as an adjunct to pharmacological treatment.

Performance Comparisons of Youth Weightlifters as a Function of Age Group and Sex.

This study was designed to provide an overview of weightlifting performance as a function of age group and sex and evaluate the potential of countermovement jump height (CMJH) as a tool to gauge performance potential. Data from 130 youth athletes (female, n = 65 & male, n = 65) were used to examine progression of performance (Total and Sinclair total) and the relationship between CMJH and Sinclair total while considering interactions between CMJH and age and/or sex. ANOVAs with post hoc analyses revealed that both totals had a statistical first-order polynomial interaction effect between age group and sex and the difference between age groups of 12–13 and 14–15 years old was statistically greater for male than female. A linear model, developed to examine the relationship, revealed that CMJH and CMJH x sex x age rejected the null hypothesis. Our primary findings are that male youth weightlifters have a higher rate of performance progression, possibly owing to puberty, and CMJH may be a better gauging tool for older male youth weightlifters.

The epidemiology of fracture-related infections in Germany

The epidemiology of fracture-related infection (FRI) is unknown, which makes it difficult to estimate future demands and evaluate progress in infection prevention. Therefore, we aimed to determine the nationwide burden’s development over the last decade as a function of age group and gender. FRI prevalence as a function of age group and gender was quantified based on annual ICD-10 diagnosis codes from German medical institutions between 2008 through 2018, provided by the Federal Statistical Office of Germany (Destatis). The prevalence of FRI increased by 0.28 from 8.4 cases per 100,000 inhabitants to 10.7 cases per 100,000 inhabitants between 2008 and 2018. The proportion of fractures resulting in FRI increased from 1.05 to 1.23%. Gender distribution was equal. Patients aged 60–69 years and 70–79 years comprised the largest internal proportion with 20.2% and 20.7%, respectively, whereby prevalence increased with age group. A trend towards more diagnoses in older patients was observed with a growth rate of 0.63 for patients older than 90 years. Increasing rates of fracture-related infection especially in older patients indicate an upcoming challenge for stakeholders in health care systems. Newly emerging treatment strategies, prevention methods and interdisciplinary approaches are strongly required.

Gender and age differences in absolute and relative handgrip strength of the Turkish population aged 8–27 years

We aimed to investigate the impact of anthropometric variables on absolute and relative hand grip strength (HGS) and associations among them in gender-specific age groups and also to evaluate normative HGS values adjusted to body mass index (BMI), fat free mass (FFM) and fat free mass index (FFMI) in healthy subjects as a function of age group and gender. A total of 567 volunteers (n=271 boys, 10.89±1.16 years, and n=296 girls, 10.86±1.07 years) participated in this study. Three consecutive trials for both hands were performed; the highest value was used as the HGS. There were no significant differences between genders in both anthropometric and strength values except FFM, FFMI and left-side grip strength (LSGS) in the 8–12 age group even though HGS values were normalized. FFM (r=0.80, r=0.86, p<0.01) and FFMI (r=0.57, r=0.76, p<0.01) had strong relationship with HGS in both females and males, respectively. The results of this study show that both age-dependent increases in HGS and gender differences are strongly associated with changes in FFM and FFMI. For this purpose, we suggest using FFM or FFMI-corrected HGS values to compare or constitute standard data as a guide for practitioners when interpreting grip strength measurements.

When time's arrow doesn't bend: APOE-ε4 influences episodic memory before old age

Episodic memory impairment is the hallmark symptom of Alzheimer's Disease (AD). However, episodic memory has also been shown to decline across the lifespan. Here, we investigated whether episodic memory is differentially affected relative to other cognitive abilities before old age, and whether being an Apolipoprotein E (APOE) ε4 carrier –a genetic risk factor for developing AD—exacerbates any such impairments. We used general linear models to test for performance differences within 4 composite measures of cognition - episodic memory, semantic memory, speed of processing, and fluid reasoning-- as a function of age group (young, Mage = 30.21 vs. middle-aged, Mage = 50.84) and APOE-ε4 genotype status (ε4+ vs. ε4-). We replicated findings of age-related reductions in episodic memory, speed of processing, and fluid reasoning, and age-related increases in semantic memory. However, we also found that APOE genotype status moderated the age-related declines in episodic memory: APOE-ε4+ middle-aged adults exhibited impairments relative to both APOE-ε4- middle-aged participants, and APOE-ε4+ younger adults. These results suggest specific and dynamic alterations to episodic memory as a function of APOE allelic variation and age.

Age differences in attitudes about older adults with dementia

AbstractDementia, a term that describes a variety of brain conditions marked by gradual, persistent and progressive cognitive decline, affects a significant proportion of older adults. Older adults with dementia are sometimes perceived less favourably than those without dementia. Furthermore, compared to persons without dementia, those with dementia are often perceived by others as having reduced personhood. This study was aimed at investigating whether differences in attitudes towards dementia and personhood perceptions vary as a function of age group, care-giver status, attitudes towards ageing, dementia knowledge, gender and education. In total 196 younger, middle-aged and older adults were recruited. Findings revealed that being a care-giver as well as having less ageist attitudes were predictive of being more comfortable around persons with dementia, having more knowledge about dementia and ascribing greater personhood to people with dementia. Those with more dementia knowledge (prior to the study) were less comfortable around people with dementia. Finally, when controlling this prior dementia knowledge, older adults were more comfortable around people with dementia compared to younger and middle-aged adults. Gender and education were not associated with any of the variables under study. Findings contribute to a better understanding of the role of age- and care-giver-related factors in the determination of attitudes towards dementia.

Preschoolers’ lexical skills in two majority languages: Is there evidence for the onset of sequential bilingualism?

Aims and objectives: This study measured bilingual lexical skills in children just starting preschool and in others who had been attending preschool for one year. It aimed to investigate how children’s lexical abilities were influenced by length of contact with structured bilingual input at school, in a context where two majority languages are taught through the educational system. Methodology: The participants were 72 children starting their first and second year in preschool, aged 2;11–3;4 ( N = 35) and 3;11–4;4 years ( N = 37), respectively. The children came from Maltese-dominant homes and attended the same state preschool where, in line with established bilingual educational policy, they were expected to receive systematic oral exposure to English. Receptive picture name judgement and picture naming tasks in Maltese and English were employed to measure receptive and expressive lexical abilities. Data and analysis: Correct receptive judgement and naming responses were analysed as a function of age group and language of testing. Findings: Comparison of 3- and 4-year-old performance revealed marked growth in Maltese but limited improvement in English for the older group. This profile was inconsistent with lexical outcomes expected for children receiving significant exposure to a second language (L2) in preschool. The findings call for reconsideration of the assumption that preschool entry for Maltese-dominant children and the sequential bilingual exposure associated with it bring about an improvement in L2 lexical abilities. School and home bilingual input, children’s learning demands and Malta’s sociolinguistic context were considered as possible contributing factors. Originality: To our knowledge, a focus on preschoolers’ lexical skills in two typologically distant, majority languages against a backdrop of stable bilingualism is novel. Significance: Given the bilingual stability and socio-cultural uniformity of the broader context for this study, the findings are proposed as a point of reference for evaluating preschoolers’ bilingual lexical skills.

Performance of semi-automated hippocampal subfield segmentation methods across ages in a pediatric sample

Episodic memory function has been shown to depend critically on the hippocampus. This region is made up of a number of subfields, which differ in both cytoarchitectural features and functional roles in the mature brain. Recent neuroimaging work in children and adolescents has suggested that these regions may undergo different developmental trajectories—a fact that has important implications for how we think about learning and memory processes in these populations. Despite the growing research interest in hippocampal structure and function at the subfield level in healthy young adults, comparatively fewer studies have been carried out looking at subfield development. One barrier to studying these questions has been that manual segmentation of hippocampal subfields—considered by many to be the best available approach for defining these regions—is laborious and can be infeasible for large cross-sectional or longitudinal studies of cognitive development. Moreover, manual segmentation requires some subjectivity and is not impervious to bias or error. In a developmental sample of individuals spanning 6–30 years, we assessed the degree to which two semi-automated segmentation approaches—one approach based on Automated Segmentation of Hippocampal Subfields (ASHS) and another utilizing Advanced Normalization Tools (ANTs)—approximated manual subfield delineation on each individual by a single expert rater. Our main question was whether performance varied as a function of age group. Across several quantitative metrics, we found negligible differences in subfield validity across the child, adolescent, and adult age groups, suggesting that these methods can be reliably applied to developmental studies. We conclude that ASHS outperforms ANTs overall and is thus preferable for analyses carried out in individual subject space. However, we underscore that ANTs is also acceptable and may be well-suited for analyses requiring normalization to a single group template (e.g., voxelwise analyses across a wide age range). Previous work has supported the use of such methods in healthy young adults, as well as several special populations such as older adults and those suffering from mild cognitive impairment. Our results extend these previous findings to show that ASHS and ANTs can also be used in pediatric populations as young as six.

A comparison of visual working memory and episodic memory performance in younger and older adults

ABSTRACTWorking memory and episodic memory decline with age. However, as they are typically studied separately, it is largely unknown whether age-associated differences are similar. A task design was developed in which visual working memory and episodic memory performances were measured using the same stimuli, with both tasks involving context binding. A 2-back working memory task was followed by a surprise subsequent recognition memory task that assessed incidental encoding of object locations of the 2-back task. The study compared performance of younger (N=30; Mage=23.5, SDage=2.9, range=20-29) and older adults (N=29; Mage=72.1, SDage=6.8, range=62-90). Older adults performed worse than younger adults, without an interaction effect. In younger, but not in older adults, performance on the two tasks was related. We conclude that although age differences (Young>Older) are similar in the working memory and incidental associative memory tasks, the relationship between the two memory systems differs as a function of age group.

Consumers’ health-related perceptions of bread – Implications for labeling and health communication

There is a wide variety of commercial bread types and the present study identifies potential pitfalls in consumer evaluations of bread from a health perspective. The aim is to describe consumers’ health-related perceptions of bread by exploring which health-related quality attributes consumers associate with bread and whether there are differences with regard to age, gender and education level. A postal and web-based sequential mixed-mode survey (n = 1134, 62% responded online and 38% by paper) with open-ended questions and an elicitation task with pictures of commercial breads were used. Responses were content analyzed and inductively categorized. Three fourths (n = 844) knew of breads they considered healthy; these were most commonly described using terms such as “coarse,” “whole grain,” “fiber rich,” “sourdough,” “crisp,” “less sugar,” “dark,” “rye,” “seeds,” “a commercial brand,” “homemade” and “kernels.” The breads were perceived as healthy mainly because they “contain fiber,” are “good for the stomach,” have good “satiation” and beneficial “glycemic properties.” The frequency of several elicited attributes and health effects differed as a function of age group (18–44 vs. 45–80 years), gender and education level group (up to secondary education vs. university). Difficulties identifying healthy bread were perceived as a barrier for consumption especially among consumers with a lower education level. Several of the health effects important to consumers cannot be communicated on food packages and consumers must therefore use their own cues to identify these properties. This may lead to consumers being misled especially if a bread is labeled e.g., as a sourdough bread or a rye bread, despite a low content.

Age-related differences in subjective recollection: ERP studies of encoding and retrieval.

The ability to mentally re-experience past events improves significantly from childhood to young adulthood; however, the mechanisms underlying this ability remain poorly understood, partially because different tasks are used across the lifespan. This study was designed to address this gap by assessing the development of event-related potential (ERP) correlates associated with subjective indices of recollection. Children, adolescents, and adults performed Tulving's () remember/know paradigm while ERPs were recorded during memory encoding (Experiment 1) and retrieval (Experiment 2). Behaviorally, children recognized fewer items than adolescents and adults. All age groups reliably made subjective judgments of recollection, although the ability to make these judgments improved with age. At encoding, the ERP effect associated with recollection was present and comparable across age groups. In contrast, the ERP effect associated with recollection at retrieval differed as a function of age group; specifically, this effect was absent in children, topographically widespread in adolescents, and, consistent with previous literature, maximal over left centro-parietal leads in adults. These findings suggest that encoding processes associated with the subsequent subjective experience of recollection may be similar among children, adolescents, and adults and that age-related improvement in recollection may be primarily attributable to the development of processes that follow the initial encoding of stimuli (i.e., consolidation, storage, retrieval).

Bone mineral density at distal forearm in men over 40 years of age in Mae Chaem district, Chiang Mai Province, Thailand: a pilot study

Objective: To study the prevalence of bone mineral density (BMD) and osteoporosis in the distal forearm among Thai men over 40 years of age in Mae Chaem District, Chiang Mai Province, Thailand.Methods: The subjects in this study were 194 Thai men, aged between 40 and 87 years who resided in Mae Chaem District, Chiang Mai Province, Thailand. Self-administered questionnaires were used for receiving the demographic characteristics information. BMD was measured by peripheral dual energy X-ray absorptiometry at the nondominant distal forearm in all men.Results: The BMD was highest in the age-group 40–49 years and lowest in the age-group 70–87 years. The average T-score at the distal forearm was also highest in the age-group 40–49 years and lowest in the age-group 70–87 years. The BMD decreased as a function of age-group (p < .05). In contrast, the BMD increased as a function of weight (p < .05). Height had weak impact on the BMD in the distal forearm (p > .05). The percentage of osteopenia and osteoporosis are increased as a function of age-group in, while decreased in that of normal bone density.Conclusions: We found the prevalence of osteoporosis in men who resided in Mae Chaem District, Chiang Mai Province, Thailand.

Socioeconomic, health, and psychosocial mediators of racial disparities in cognition in early, middle, and late adulthood.

Racial disparities in cognitive performance exist across the life course, but it is not known whether mediators of disparities differ by age. Understanding sources of cognitive disparities at different ages can inform policies and interventions. Data were obtained for non-Hispanic Black and White respondents to The National Survey of Midlife Development in the United States from 3 age groups: 28-44 (N = 1210; 20% Black); 45-64 (N = 2693; 15% Black); and 65-85 (N = 1298; 11% Black). Moderated mediation models characterized direct and indirect effects of race on episodic memory and executive function composite scores through economic, health, and psychosocial variables as a function of age group. Education, income, chronic health conditions, and external locus of control mediated cognitive disparities across the life course, although income was a stronger mediator at younger ages. Perceived discrimination was a weaker mediator among young adults due to an absence of racial differences in perceived discrimination in that group. Despite multiple indirect effects, there were still significant unexplained effects of race on cognition that were not moderated by age group. Interventional work is needed to determine whether increasing educational attainment and income, and reducing chronic health conditions and perceived constraints among Blacks, reduce cognitive disparities. Targeting income inequality and discrimination (or buffering the impact of those variables) may be differently effective at reducing cognitive disparities at different stages of the adult life course. (PsycINFO Database Record

The Importance of Properly Compensating for Head Movements During MEG Acquisition Across Different Age Groups.

Unlike EEG sensors, which are attached to the head, MEG sensors are located outside the head surface on a fixed external device. Subject head movements during acquisition thus distort the magnetic field distributions measured by the sensors. Previous studies have looked at the effect of head movements, but no study has comprehensively looked at the effect of head movements across age groups, particularly in infants. Using MEG recordings from subjects ranging in age from 3months through adults, here we first quantify the variability in head position as a function of age group. We then combine these measured head movements with brain activity simulations to determine how head movements bias source localization from sensor magnetic fields measured during movement. We find that large amounts of head movement, especially common in infant age groups, can result in large localization errors. We then show that proper application of head movement compensation techniques can restore localization accuracy to pre-movement levels. We also find that proper noise covariance estimation (e.g., during the baseline period) is important to minimize localization bias following head movement compensation. Our findings suggest that head position measurement during acquisition and compensation during analysis is recommended for researchers working with subject populations or age groups that could have substantial head movements. This is especially important in infant MEG studies.

Is the time course of lexical activation and competition in spoken word recognition affected by adult aging? An event-related potential (ERP) study

Adult aging is associated with decreased accuracy for recognizing speech, particularly in noisy backgrounds and for high neighborhood density words, which sound similar to many other words. In the current study, the time course of neighborhood density effects in young and older adults was compared using event-related potentials (ERP) and behavioral responses in a lexical decision task for spoken words and nonwords presented either in quiet or in noise. Target items sounded similar either to many or to few other words (neighborhood density) but were balanced for the frequency of their component sounds (phonotactic probability). Behavioral effects of density were similar across age groups, but the event-related potential effects of density differed as a function of age group. For young adults, density modulated the amplitude of both the N400 and the later P300 or late positive complex (LPC). For older adults, density modulated only the amplitude of the P300/LPC. Thus, spreading activation to the semantics of lexical neighbors, indexed by the N400 density effect, appears to be reduced or delayed in adult aging. In contrast, effects of density on P300/LPC amplitude were present in both age groups, perhaps reflecting attentional allocation to items that resemble few words in the mental lexicon. The results constitute the first evidence that ERP effects of neighborhood density are affected by adult aging. The age difference may reflect either a unitary density effect that is delayed by approximately 150ms in older adults, or multiple processes that are differentially affected by aging.