The power of the written word: Comparing word meaning inferencing from auditory and written modalities throughout grade school

Previous research indicates that word learning from auditory contexts may be more effective than written context at least through fourth grade. However, no study has examined contextual differences in word learning in older school-aged children when reading abilities are more developed. Here we examined developmental differences in children's ability to deduce the meanings of unknown words from the surrounding linguistic context in the auditory and written modalities and sought to identify the most important predictors of success in each modality. A total of 89 children aged 8-15 years were randomly assigned to either read or listen to a narrative that included eight novel words, with five exposures to each novel word. They then completed three posttests to assess word meaning inferencing. Children across all ages performed better in the written modality. Vocabulary was the only significant predictor of success on the word inferencing task. Results indicate support for written stimuli as the most effective modality for novel word meaning deduction. Our findings suggest that the presence of orthographic information facilitates novel word learning even for early, less proficient readers.

Temporal and topographical changes in theta power between middle childhood and adolescence during sentence comprehension

Time frequency analysis of the EEG is increasingly used to study the neural oscillations supporting language comprehension. Although this method holds promise for developmental research, most existing work focuses on adults. Theta power (4–8 Hz) in particular often corresponds to semantic processing of words in isolation and in ongoing text. Here we investigated how the timing and topography of theta engagement to individual words during written sentence processing changes between childhood and adolescence (8–15 years). Results show that topographically, the theta response is broadly distributed in children, occurring over left and right central-posterior and midline frontal areas, and localizes to left central-posterior areas by adolescence. There were two notable developmental shifts. First, in response to each word, early (150–300 msec) theta engagement over frontal areas significantly decreases between 8 and 9 years and 10–11 years. Second, throughout the sentence, theta engagement over the right parietal areas significantly decreases between 10 and 11 years and 12–13 years with younger children’s theta response remaining significantly elevated between words compared to adolescents’. We found no significant differences between 12 and 13 years and 14–15 years. These findings indicate that children’s engagement of the language network during sentence processing continues to change through middle childhood but stabilizes into adolescence.

Gender differences in mothers' spatial language use and children's mental rotation abilities in Preschool and Kindergarten

Mental rotation has emerged as an important predictor of success in Science, Technology, Engineering, and Math (STEM). By the age of 4.5 years, boys outperform girls in these abilities. Because parents use less spatial language with girls at this age (Pruden and Levine, 2017), the amount of spatial language that children are exposed to at home is believed to be one potential contributor to this disparity in preschool age children. To date, it is unclear if this gender difference continues when children enter school. To address this question in this study, children not yet in kindergarten (PreK) and kindergarten and first grade children (K+) were recorded playing with their mothers using magnetic tile toys followed by children's completion of a mental rotation task. As expected, mothers used more spatial language with PreK boys than girls; however, this relationship reversed in K+, with mothers using significantly more spatial language with girls than boys. Surprisingly, despite this, boys outperformed girls on the mental rotation task. These findings suggest that although girls' exposure to spatial language is higher after entry into school, this language difference is not reflected in increases in mental rotation abilities. Thus, earlier exposure to spatial language may be vital for the development of mental rotation abilities.

Using the N400 event-related potential to study word learning from context in children from low- and higher-socioeconomic status homes

Children from low-socioeconomic status (SES) homes have significantly smaller vocabularies than their higher-SES peers, a gap that increases over the course of the school years. One reason for the increase in this vocabulary gap during the school years is that children from low-SES homes learn fewer words from context than their higher-SES peers. To better understand how the process of word learning from context might differ in children related to SES, we investigated changes in the N400 event-related potential (ERP) as children from low- and higher-SES homes learned new words using only the surrounding linguistic context. There were no differences in the N400 response to known words related to SES. In response to the target word being learned, children from higher-SES homes, like adults in previous studies, exhibited an attenuation of the N400 across exposures as they attached meaning to it. Children from low-SES homes did not show this same attenuation. These findings support previous work showing that children from low-SES homes may have differences or more variability in the neural components supporting language processing, and they extend previous work to illustrate how this variability may relate to word learning and, ultimately, vocabulary growth.