Poster A59, Thursday, August 16, 10:15 am – 12:00 pm, Room 2000AB
Socioeconomic Status (SES) differences in children’s N400 responses when learning new words from linguistic context.
Yvonne Ralph1, Julie M. Schneider1, Mandy J. Maguire1;1University of Texas at Dallas
Introduction: Coming from a low-income home has negative impacts on language and brain development, vocabulary being particularly vulnerable (Hoff, 2013; Nobel et al. 2012). As children enter school this vocabulary disparity is exacerbated (Bradley & Corwyn, 2002). To better understand how word learning skills and the neural underpinnings of word learning may differ related to SES, we recorded the EEG of children from low SES (LSES) and higher SES (HSES) homes as they performed a word learning from context task. Our primary goal is to identify if the groups display differences in word learning abilities or neural markers of word learning based on the N400 which, in previous studies with both children (Abel et al, 2017) and adults (Mestres-Misse, et al 2007), has been shown to reliably index word learning across presentations. Methods: Sixty-four (30 low SES) right-handed, 8 to 10-year-old (M=8.97; SD =.78) children had their behavioral and EEG responses recorded while engaged in a word learning task. SES was based on government standards for free or reduced lunch. Stimuli were 50 sentence triplets, presented one at a time, on a computer monitor. Each sentence in the triplet ended in the same made up word. After the presentation of each triplet, participants indicated whether the made-up word represented a real word and, if so, what it was. Responses were correct if the participant identified the intended target word or if their response created three semantically plausible sentences. All of the words in the sentence, other than the target word, were in children’s productive vocabularies by about 30 months of age (Fenson, et al 1994). Analysis Only correct trials were included in the analysis. ERPs were time-locked to the final target word in each sentence and the corresponding EEG was epoched from -100 msec to1500 msec. Data were averaged across trials and subjects and baseline corrected. The average amplitude across frontal electrodes between 300-500 msec post stimulus was computed for each presentation and these averages were statistically compared using a 2(SES) x 3(Presentation) RMANOVA. Results Children from low SES homes learned fewer words (M=44%; SD =.23) than their higher SES peers (M=57%; SD=.19; t(59)=2.41, p<.02). The N400 analysis revealed a main effect of presentation (F(2,124)=4.83, p=.01), but no interaction. Due to substantial variability in the LSES group (SD=2.5, high SES group SD=1.6) we analyzed each group independently. The N400 attenuated across presentations for the HSES group (F(2,131)=2.86, p=.03, one tailed), but not the LSES group. Conclusion Children from LSES homes learned fewer words than their higher SES peers and failed to exhibit an N400 attenuation across presentations. We hypothesize that the lack of N400 attenuation is due to greater variability in neural engagement within and between participants in the LSES group. This high level of variability in the N400 provides evidence that children from LSES homes may engage different compensatory strategies for word learning (Maguire et al., 2018) as well as evidence of differences in neural structures underlying language processing (Nobel et al., 2012).
Topic Area: Language Development