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1 Psychometric Characteristics of the Grenada Learning and Memory Scale: An Innovative Tool for Preschool Memory Assessment in Resource-Limited Regions
- Roberta Evans, Lauren Mohammed, Kemi S Burgen, Rashida Isaac, Toni Murray, Patricia Kandle, Mira E Cheng, Randall Waechter, Barbara Landon, Karen Blackmon
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 209-210
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Objective:
Neuropsychological assessment of preschool children is essential for early detection of delays and referral for intervention prior to school entry. This is especially relevant in low-and middle-income countries (LMICs), which are disproportionately impacted by micronutrient deficiencies and teratogenic exposures. There are limited options for assessment of preschool learning and memory, developed and validated in resource-limited regions. The Grenada Learning and Memory Scale (GLAMS) was created for use in the Caribbean using an indigenous “ground-up” approach, with feedback from regional stakeholders at various stages of development. The GLAMS contains two subtests - a verbal list-learning task, which imagines a trip to the shop to buy culturally familiar items, and a face-name associative learning task using locally-drawn faces of Caribbean children. There are two versions: a 4-item version for 3-year-olds and a 6-item version for 4 and 5-year-olds. Here we present descriptive data and psychometric features for the GLAMS from an initial preschool sample.
Participants and Methods:Participants were recruited from a social-emotional intervention study (SGU IRB#14099) in Grenada between 2019-2021. Children were between 36 and 72 months of age, primarily English-speaking, and had no known history of neurodevelopmental disorders. Trained Early Childhood Assessors administered the GLAMS and NEPSY-II in public preschools and homes across Grenada. Exploratory descriptive statistics characterized participant sociodemographics and test score distributions. Spearman correlations, MannWhitney U, and Kruskal-Wallis tests examined the impact of sociodemographics on test scores. Internal reliability was assessed with coefficient alpha. NEPSY-II subtests were used to assess convergent validity, with the prediction that the highest correlations would be observed for NEPSY-II Sentence Repetition. Test engagement (as reflected by “zero-learning”, “some learning”, and “positive learning curves”) was assessed across each age bracket (in 6-month increments). We assessed and summarized barriers to engagement qualitatively.
Results:The sample consisted of 304 children (152 males,152 females). Participants were predominantly Afro-Caribbean and Indo-Caribbean. Parent education and household income (Mdn=$370-740 USD per month) were consistent with the general population. GLAMS internal consistency was reliable (a=0.713). There were age effects on list-learning (rs=0.51; p<0.001), list recall (rs=0.51; p<0.001), face-name learning (rs=0.30;p<0.001), and face-name recall (rs=0.25; p<0.001). There were gender effects on list-learning (p=0.02) and list recall (p=0.01) but not face-name learning or recall. All GLAMS subtests were correlated with NEPSY Sentence Repetition (rs=0.22-0.34; p<0.001). There was sufficient sampling of males and females across all 6 age brackets. As age increased, a higher proportion of children showed a positive learning curve (and fewer “zero-scores”) on verbal learning (X2 =30.88, p<0.001) and face-name learning (X2=22.19, p=0.014), demonstrating increased task engagement as children mature. There were various qualitative observations of why children showed “zero-scores”, ranging from environmental distractions to anxiety and inattention.
Conclusions:As far as we know, the GLAMS is the first preschool measure of learning and memory developed indigenously from within the Caribbean. It shows reliable internal consistency, expected age and gender effects and convergent validity. These initial results are encouraging and support continued efforts to establish test-retest and inter-rater reliability. Plans include validation in clinical samples, scale-up to other Caribbean countries, and eventual adaptation across global LMICs.
The effects of dating uncertainties on net accumulation estimates from firn cores
- Summer Rupper, William F. Christensen, Barry R. Bickmore, Landon Burgener, Lora S. Koenig, Michelle R. Koutnik, Clément Miège, Richard R. Forster
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- Journal:
- Journal of Glaciology / Volume 61 / Issue 225 / 2015
- Published online by Cambridge University Press:
- 10 July 2017, pp. 163-172
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The mean, trend and variability of net snow accumulation in firn cores are often used to validate model output, develop remote-sensing algorithms and quantify ice-sheet surface mass balance. Thus, accurately defining uncertainties associated with these in situ measurements is critical. In this study, we apply statistical simulation methods to quantify the uncertainty in firn-core accumulation data due to the uncertainty in depth–age scales. The methods are applied to a suite of firn cores from central West Antarctica. The results show that uncertainty in depth–age scales can give rise to spurious trends in accumulation that are the same order of magnitude as accumulation trends reported in West Antarctica. The depth–age scale uncertainties also significantly increase the apparent interannual accumulation variability, so these uncertainties must first be accounted for before using firn-core data to assess such processes as small-spatial-scale variability. Better quantification of error in accumulation will improve our ability to meaningfully compare firn-core data across different regions of the ice sheet, and provide appropriate targets for calibration and/or validation of model output and remote-sensing data.