Longitudinal Development of Delay and Conflict Inhibitory Control in 2- to 4-Year-Old Children

• In Event: Poster Session 09
  In Poster Session: PS 09 Topic - Attention, Learning, Memory

Abstract

Inhibitory control (IC) predicts performance across a host of developmental outcomes related to self-regulation and academic achievement (Blair & Razza, 2007; Carlson & Wang, 2007). Evidence suggests that IC skills develop rapidly in early childhood (Carlson, 2005). Nonetheless, considerably less research has examined factors that may contribute to the independent developmental trajectories of delay and conflict IC across toddlerhood and into the preschool period (Garon, Bryson, & Smith, 2008). It has also been proposed that endogenous (e.g., language) and exogenous factors (e.g., maternal education) may facilitate children’s developing inhibition skills. In this sense, language may enable children to better understand task instructions and utilize self-talk to regulate impulses (Vallotton & Ayoub, 2012; Watson & Bell, 2014), while maternal education represents resources available to mothers that may foster children’s developing IC skills (Montroy et al., 2019). The purpose of this study was to examine delay and conflict IC trajectories as a function of maternal education and 24-month-old expressive vocabulary.
In this longitudinal study (n = 285, 144 females), IC was measured at 24-, 36-, and 48-months of age. Delay IC was measured using the Tongue task (Kochanska et al., 1996), which requires children to inhibit eating a cracker placed on their tongue for increasingly longer intervals of time. Conflict IC was measured using the Simon Says Puppet task (Reed, Pien, & Rothbart, 1984) where children are instructed to follow the directions of a “nice” puppet and ignore the directions of a different, “mean” puppet. Mothers reported their education attainment on a demographic questionnaire. Expressive vocabulary percentile was calculated at 24-months using the MacArthur-Bates Communicative Development Inventories (MCDI – Words & Sentences).
For both delay and conflict IC, the best-fitting multilevel growth model was a model with time entered as the L1 variable, and both expressive vocabulary percentile and maternal education entered as the L2 predictors. For delay IC, results indicated that only expressive vocabulary significantly predicted initial status, t (282) = 3.819, p <0.001, and IC growth, t (282) = -3.090, p = 0.002 (Figure 1). In other words, 24-month expressive vocabulary positively predicted concurrent delay IC performance, and thus children with better language skills at 2 years demonstrated a slower growth trajectory.
For conflict IC, it was found that expressive vocabulary, t (282) = -3.733, p <0.001 significantly predicted initial status, yet both expressive vocabulary, t (282) = 4.558, p <0.001, and maternal education, t (282) = 2.021, p = 0.044, accounted for IC growth (Figure 2). Thus, superior expressive vocabulary at 24-months was associated with poorer performance on the conflict IC task, which replicates an interesting, previous finding (Joyce et al., 2016). It’s possible that the acquisition of a relatively new skill (i.e., oral productive language) impeded performance on a more cognitively complex IC task that requires both inhibitory control and working memory. Nonetheless, both 24-month expressive vocabulary and maternal education positively influenced conflict IC growth. Taken together, these findings illustrate unique differences in the development of delay and conflict IC as influenced by maternal education and language in toddlerhood.

Authors

• Madeleine Diane Bruce, University of Utah
  Presenting Author

• Martha Ann Bell, Virginia Polytechnic Institute and State University
  Non-Presenting Author