Language requires both storage and composition. However, exactly what is retrieved from memory and what is assembled remains controversial, especially for inflected words. Here, "imageability effects" is introduced as a new diagnostic of storage and a complement to frequency effects. In 2 studies of past-tense morphology, more reliable imageability and frequency effects were found on irregulars than on regulars. An interaction with sex was also observed: Males but not females showed more reliable frequency and imageability effects for irregulars than for regulars; females but not males showed signs of storage for regulars, particularly among higher frequency forms. Overall, the findings validate imageability effects as another diagnostic of storage and suggest that the line between storage and computation is not a simple function; rather, it depends upon the interplay of both item- and subject-specific factors.

This study investigates the storage vs. composition of inflected forms in typically-developing children. Children aged 8–12 were tested on the production of regular and irregular past-tense forms. Storage (vs. composition) was examined by probing for past-tense frequency effects and imageability effects – both of which are diagnostic tests for storage – while controlling for a number of confounding factors. We also examined sex as a factor. Irregular inflected forms, which must depend on stored representations, always showed evidence of storage (frequency and/or imageability effects), not only across all children, but also separately in both sexes. In contrast, for regular forms, which could be either stored or composed, only girls showed evidence of storage. This pattern is similar to that found in previously-acquired adult data from the same task, with the notable exception that development affects which factors influence the storage of regulars in females: imageability plays a larger role in girls, and frequency in women. Overall, the results suggest that irregular inflected forms are always stored (in children and adults, and in both sexes), whereas regulars can be either composed or stored, with their storage a function of various item- and subject-level factors.

Background Eggs are a rich source of choline, an essential nutrient important for child growth and development. In a randomized trial of one egg/day among young children in Ecuador, an egg intervention led to significant improvements in growth, which was partially mediated by increased plasma choline concentration. A similar trial in Malawi (clinicaltrials.gov: NCT03385252) found little improvement in child growth or development. Objective We aimed to evaluate the effect of one egg/day for 6 months on plasma choline concentrations among Malawian children enrolled in a randomized trial. Methods Infants age 6-9 months in rural Malawi were randomized to receive one egg/day (n = 331) or serve as a nonintervention control (n = 329) for 6 months. Anthropometric, developmental, and dietary data were collected at baseline and 6 month follow up, along with a blood draw. Plasma choline, betaine, dimethylglycine, trimethylamine N-oxide (TMAO), and docosahexaenoic acid were measured at both time points using UPLC-MS/MS (n = 200 per group). Linear regression analysis was used to determine the difference in plasma choline and related metabolites between groups after 6 months of intervention. Results Plasma choline, betaine, dimethylglycine, and docosahexaenoic acid concentrations did not differ between groups at 6 month follow up. Plasma TMAO was significantly (26% [95% CI: 7%, 48%]) higher in the egg intervention group in a fully adjusted model. Conclusions Provision of one egg/day for 6 months did not result in increases in plasma choline or related metabolites, except TMAO. This may partially explain the lack of effect on growth and development. Additional interventions are needed to improve choline status, growth, and development in this population.

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