The Effects of Socioeconomic Status on Working Memory are Mediated by Intersensory Processing in Infancy

• In Event: Attention, learning and memory in infancy

Abstract

Socioeconomic status (SES) is a well-established predictor of language and cognitive functioning in childhood (Hart & Risley, 1995; Mistry et al., 2008), including executive functioning (EF; Lawson et al., 2017). In infancy, intersensory processing (IP) of faces and voices—selectively attending to redundant properties of audiovisual speech (e.g., temporal synchrony, tempo, rhythm of speech)—predicts language and cognitive development (e.g., Edgar et al., 2022). However, links between IP and EF have not yet been directly assessed. Both IP and EF involve attentional control (e.g., focusing on relevant information while ignoring irrelevant information). Further, attentional control predicts working memory, a dimension of EF, in children (Plebanek & Sloutsky, 2018) and adults (Conway et al., 2001). Finally, little is known about relations between IP and SES. Thus, the present study examines links among SES, IP in infancy, and working memory in early childhood. Children (N=103) participated at 12- and 36-months of age as part of a larger longitudinal study. At the 12-month visit, IP was assessed via a newly-developed individual difference measure, the Multisensory Attention Assessment Protocol (see Figure 1; Bahrick et al., 2018). On each of 12 trials, following a 3-s dynamic central visual event, children view two events (women speaking, objects dropping) along with the natural soundtrack synchronized with one of them. For half the trials, the central event remains on throughout the lateral events providing an additional source of distracting information, and for the other half, it disappears at the onset of the lateral events. IP is calculated as the proportion of total looking time to the sound-synchronous event. At the 36-month visit, children received the WPPSI-IV (Weschler, 2012) to index working memory, as well as their visual-spatial and verbal comprehension abilities. Parents also completed a background questionnaire to index SES (maternal education, paternal education, and income). Results indicated that IP was correlated with maternal and paternal education (ps<.01) and working memory (p=.003). Further, maternal education and income were also correlated with working memory (ps<.02). Given these patterns of correlations, we tested a model to assess whether IP mediated the relation between SES (a latent variable with maternal education, paternal education, and income) and working memory (see Figure 2). Results revealed that SES significantly predicted IP (b=.27, p=.02), which in turn, significantly predicted working memory (b=.21, p=.03). SES marginally predicted working memory (b=.24, p=.08). Thus, IP partially mediates the relation between SES and working memory. All results remained significant even when controlling for both visual spatial and verbal comprehension skills. The present study reveals that children living in higher-SES homes show greater IP at 12-months of age, and in turn, show greater working memory skills at 36-months of age. These findings are consistent with the view that children from higher SES environments have greater attention control promoting better face-voice and object-sound matching, and in turn, working memory, a component of EF. Future research will examine SES and IP as foundations of EF by including other components of EF and extending to older children.

Authors

• Elizabeth V. Edgar, Yale University
  Presenting Author

• Bret Eschman, University of Tennessee at Chattanooga

• James Torrence Todd, Florida International University

• Kaitlyn Testa, Florida International University

• Bethany K Ramirez, Florida International University

• Lorraine E. Bahrick, Florida International University