Learning Word Meanings: Overnight Integration and Study Modality Effects

<div><p>According to the complementary learning systems (CLS) account of word learning, novel words are rapidly acquired (learning system 1), but slowly integrated into the mental lexicon (learning system 2). This two-step learning process has been shown to apply to novel word <i>forms</i>. In this study, we investigated whether novel word <i>meanings</i> are also gradually integrated after acquisition by measuring the extent to which newly learned words were able to prime semantically related words at two different time points. In addition, we investigated whether modality at study modulates this integration process. Sixty-four adult participants studied novel words together with written or spoken definitions. These words did not prime semantically related words directly following study, but did so after a 24-hour delay. This significant increase in the magnitude of the priming effect suggests that semantic integration occurs over time. Overall, words that were studied with a written definition showed larger priming effects, suggesting greater integration for the written study modality. Although the process of integration, reflected as an increase in the priming effect over time, did not significantly differ between study modalities, words studied with a written definition showed the most prominent positive effect after a 24-hour delay. Our data suggest that semantic integration requires time, and that studying in written format benefits semantic integration more than studying in spoken format. These findings are discussed in light of the CLS theory of word learning.</p></div

Mean Percentage (<i>SD</i>) of Word Meanings Responded as Known.

<p>Mean Percentage (<i>SD</i>) of Word Meanings Responded as Known.</p

Example for Each Type of Word Pair Used in the primed Lexical Decision Task.

<p><i>Note</i>. Italic words are English translations of Dutch words. Pseudoword targets do not exist as real words in the Dutch language and they were not pseudohomophones.</p><p>Example for Each Type of Word Pair Used in the primed Lexical Decision Task.</p

Mean Reaction Times (<i>SD</i>) and Mean Priming Effects (<i>SD</i>) in the primed Lexical Decision Task.

<p><i>Note</i>. <i>SD</i> = Standard Deviation; Both reaction times and priming effects are presented in ms.</p><p>^aPriming effect does not always match “<i>M</i>_{RT unrelated}—<i>M</i>_{RT related}” because the difference was calculated for each participant before averaging.</p><p>Mean Reaction Times (<i>SD</i>) and Mean Priming Effects (<i>SD</i>) in the primed Lexical Decision Task.</p

Predictors of receptive and expressive vocabulary development in children with Down syndrome

<p><i>Purpose</i>: There is a lack of longitudinal data on predictors of vocabulary development in children with Down syndrome (DS). In typically developing children, many internal and external predictors of vocabulary development have been determined before. The purpose of the present study was to investigate the role of these variables in the receptive and expressive vocabulary development of children with DS.</p> <p><i>Method</i>: The present study used a longitudinal design in young children with DS to study the vocabulary development over a period of 1.6 years and investigated the possible predictive role of child-related and environmental variables.</p> <p><i>Result</i>: Receptive vocabulary development was best predicted by the adaptive level of functioning and early receptive vocabulary skills. Expressive vocabulary development was best predicted by the adaptive level of functioning, receptive vocabulary, maternal educational level, level of communicative intent of the child, attention skills and phonological/phonemic awareness.</p> <p><i>Conclusion</i>: A wide range of internal and external predictors for vocabulary development of children with DS was found. Predictors resemble those predicting vocabulary development in peers with typical development between 1 and 6 years of age, as identified in other studies.</p

Procedure.

<p>On Day 1 participants were tested on the knowledge of the meaning of the words they were about to study. In the study phase, 64 novel and 64 known written words were studied, with their definitions (meaning) presented in written or spoken format (Modality = between-participants factor). Half of the studied words served as primes in a primed lexical decision task (pLDT) on Day 1 and the other half on Day 2 (Day = within-participants factor). Both pLDTs were followed by a meaning recall and meaning recognition test of the words that had just been used as primes in the pLDT. An example trial of a related prime-target pair in the pLDT is shown in the lower part of the figure; participants had to indicate whether a target was an existing Dutch word or not (lexical decision), and the target (e.g., <i>gewei</i> = antlers in Dutch) was primed with one of the studied words (e.g., <i>sambar</i>).</p