Development of self-derivation through memory integration and relations with world knowledge.

Accumulating world knowledge is a major task of development and education. The productive process of self-derivation through memory integration seemingly is a valid model of the process. To test the model, we examined relations between generation and retention of new factual knowledge via self-derivation through integration and world knowledge as measured by standardised assessments. We also tested whether the productive process of self-derivation predicted world knowledge even when a measure of learning through direct instruction also was considered. Participants were 162 children ages 8-12 years (53% female; 15% Black, 6% Asian, 1% Arab, 66% White, 5% mixed race, 7% unreported; 1% Latinx). Age accounted for a maximum of 4% of variance in self-derivation and retention. In contrast, substantial individual variability related to general knowledge and content knowledge in several domains, explaining 20-40% variance. In each domain for which self-derivation performance was a unique predictor, it explained a nominally greater share of the variance than the measure of learning through direct instruction. The findings imply that individual variability in self-derivation has functional consequences for accumulation of semantic knowledge across the elementary-school years.

This should help with that: A behavioral investigation into self-derivation of knowledge about prescription medications.

Self-derivation of new factual knowledge is crucial for building a knowledge base. In three experiments, we investigated self-derivation about prescription medications. In Experiment 1, adults self-derived new knowledge across textual materials on 40% of trials. Participants in Experiment 2 performed similarly (42%), even when half the information was presented in videos. It was crucial that participants received both learning episodes to successfully self-derive: control condition participants received half the necessary information and performed significantly lower. When a delay was imposed between related facts in Experiment 3, participants self-derived on only 33% of trials and performance did not differ from the control condition. The present research expanded our understanding of adults' learning and self-derivation across media about medications. It revealed room for improvement in adults' learning and self-derivation about health information. This work suggests the need to identify factors that alter performance, including better understanding of the properties of information sources.

Putting the pieces together: Cognitive correlates of self-derivation of new knowledge in elementary school classrooms.

A central goal of development and formal education is to build a knowledge base. Accumulating knowledge relies, in part, on self-derivation of new semantic knowledge via integration of separate yet related learning episodes. Previous tests of self-derivation evidence both age-related and significant individual variability in self-derivation performance in the laboratory and the classroom due in part to individual differences in verbal comprehension (children and adults) and working memory (adults only). In the only extant investigation of cognitive correlates of children's successful self-derivation in the classroom, 3rd graders' verbal comprehension predicted self-derivation, whereas working memory did not. In the current research, we expanded the battery of cognitive correlates investigated, the age range of participants (8-11 years), and the sample size (N = 330) to examine candidate sources of variability in self-derivation. More specifically, in a diverse sample, we measured children's auditory and spatial working memory, inhibitory control, metacognitive awareness, verbal comprehension, and metacognitive judgments at test for self-derivation. Metacognition was of particular interest in the current research because little is currently known about how children's understanding of their cognition, at the trait or item-specific level, may affect their derivation of new knowledge. Only verbal comprehension and metacognitive knowledge predicted children's self-derivation performance; children's metacognitive judgments at the time of testing for self-derivation were not related to their performance. These findings suggest that having both semantic knowledge and knowledge of one's self as a learner, as well as knowing how to use one's knowledge, support further knowledge base development.

Relating a picture and 1000 words: Self-derivation through integration within and across presentation formats.

To build knowledge, separate yet related learning episodes can be integrated with one another and then used to derive new knowledge. Separate episodes are often experienced through different formats, such as text passages and graphic representations. Accordingly, in the present research, we tested integration of learning episodes provided through different presentation formats with children in the laboratory (Experiment 1; n = 24; M = 8.36 years) and in classrooms (Experiment 2; n = 85; M = 9.34 years and Experiment 3; n = 154; M = 10.67 years). Children in the laboratory were successful in both same-format and different-format conditions. Children in the classroom were also successful in both conditions, but in Exp. 2 showed a cost to integration across two different presentation formats compared to the same-format condition. In Exp. 3, greater support for encoding the graphic information was added and performance no longer showed a cost between conditions.

Relations between neural structures and children's self-derivation of new knowledge through memory integration.

Accumulation of semantic or factual knowledge is a major task during development. Knowledge builds through direct experience and explicit instruction as well as through productive processes that permit derivation of new understandings. In the present research, we tested the neural bases of the specific productive process of self-derivation of new factual knowledge through integration of separate yet related episodes of new learning. The process serves as an ecologically valid model of semantic knowledge accumulation. We tested structure/behavior relations in 5- to 8-year-old children, a period characterized by both age-related differences and individual variability in self-derivation, as well as in the neural regions implicated in memory integration, namely the hippocampus and prefrontal cortex. After controlling for the variance in task performance explained by age, sex, verbal IQ, and gray-matter volume (medial prefrontal cortex, mPFC, only), we observed relations between right mPFC thickness and memory for information explicitly taught to the children as well as the new information they self-derived; relations with the volume of the right hippocampus approached significance. This research provides the first evidence of the neural substrate that subserves children's accumulation of knowledge via self-derivation through memory integration, an empirically demonstrated, functionally significant learning mechanism.

Suggested use of sensitive measures of memory to detect functional effects of maternal iodine supplementation on hippocampal development.

Maternal hypothyroxinemia secondary to iodine deficiency may have neurodevelopmental effects on the specific neurocognitive domain of memory. Associated disruption of thyroid hormone-dependent protein synthesis in the hippocampus has the potential to result in compromised development of the structure with consequential impairments in memory function. Despite links between maternal iodine deficiency during gestation and lactation and abnormal hippocampal development in rat fetuses and pups, there has been little research on the specific function of memory in human infants and young children born to iodine-deficient mothers. Several candidate measures have proven to be sensitive to the effects of gestational iron deficiency on memory function in infants and young children, including habituation and dishabituation, imitation-based tasks, and event-related potentials. Such measures could be used to test the effects of maternal iodine supplementation on the specific neurocognitive domain of memory in infants and young children. Furthermore, progress in understanding the effects of maternal iodine supplementation on neurocognitive development could be accelerated by the development of a nonhuman primate model to complement the rodent model.