Explaining Brain-Behavior Relations: Inhibitory Control as an Intermediate Phenotype Between the N2 ERP and the Externalizing Spectrum in Childhood.

Identifying neural and cognitive mechanisms in externalizing problems in childhood is important for earlier and more targeted intervention. Meta-analytic findings have shown that smaller N2 event-related potential (ERP) amplitudes, thought to reflect inhibitory control, are associated with externalizing problems in children. However, it is unclear how (i.e., through which cognitive processes) N2 amplitudes relate to externalizing problems. We examined whether inhibitory control may be a cognitive process that links N2 amplitudes and externalizing problems in early childhood. Children (N = 147, 74 girls) were assessed at four time points, spanning 3-7 years of age. Children's externalizing behavior was assessed via questionnaires completed by mothers, fathers, and teachers/secondary caregivers. Children's inhibitory control was assessed using eleven performance-based tasks and two questionnaires. Developmental scaling linked differing measures of inhibitory control and externalizing behavior across ages onto the same scale. Children's N2 amplitudes were extracted from electroencephalography data collected during a go/no-go task. Smaller N2 amplitudes were associated with externalizing problems and poorer inhibitory control. A concurrent analysis of indirect effects revealed that poorer inhibitory control partially explained the association between smaller N2 amplitudes and externalizing problems, even when controlling for the child's age, sex, and socioeconomic status. This is among the first studies to link N2 amplitudes, inhibitory control, and externalizing problems during early childhood. Findings suggest that smaller N2 amplitudes may be an early neural indicator of inhibitory control deficits and externalizing psychopathology. Moreover, inhibitory control may be an important target for early intervention in the development of externalizing psychopathology.

The P3 ERP in Relation to General Versus Specific Psychopathology in Early Childhood.

There is considerable covariation between externalizing and internalizing problems across the lifespan. Partitioning general and specific psychopathology is crucial to identify (a) processes that confer specific risk for externalizing versus internalizing problems and (b) transdiagnostic processes that confer risk for the covariation between externalizing and internalizing problems. The oddball P3 event-related potential (ERP) component, thought to reflect attentional orienting, has been widely examined in relation to psychopathology. However, prior studies have not examined the P3-or other aspects of neural functioning-in relation to general versus specific psychopathology in children. The present study examined whether children's (N = 124, ages 3-7 years) P3 amplitudes were associated with general versus specific psychopathology. Children's electroencephalography data were recorded during an oddball task. Parents rated their children's externalizing and internalizing problems. Using bifactor models to partition variance in parents' ratings of children's psychopathology symptoms, we examined children's P3 amplitudes in relation to three latent factors: (1) the general factor of psychopathology-the covariation of externalizing and internalizing psychopathology, (2) unique externalizing problems-the variance in externalizing problems after controlling for the general factor, and (3) unique internalizing problems. Results indicated that smaller P3 amplitudes were associated with unique externalizing problems at ages 3-5, and with general psychopathology at ages 6-7. Findings suggest that smaller P3 amplitudes may be associated with externalizing problems from a very young age. Moreover, there may be a developmental shift in the functional significance of the P3 in relation to general and specific psychopathology in childhood.

Studying children's growth in self-regulation using changing measures to account for heterotypic continuity: A Bayesian approach to developmental scaling.

Self-regulation is thought to show heterotypic continuity-its individual differences endure but its behavioral manifestations change across development. Thus, different measures across time may be necessary to account for heterotypic continuity of self-regulation. This longitudinal study examined children's (N = 108) self-regulation development using 17 measures, including 15 performance-based measures, two questionnaires, and three raters across seven time points. It is the first to use different measures of self-regulation over time to account for heterotypic continuity while using developmental scaling to link the measures onto the same scale for more accurate growth estimates. Assessed facets included inhibitory control, delayed gratification, sustained attention, and executive functions. Some measures differed across ages to retain construct validity and account for heterotypic continuity. A Bayesian longitudinal mixed model for developmental scaling was developed to link the differing measures onto the same scale. This allowed charting children's self-regulation growth across ages 3-7 years and relating it to both predictors and outcomes. Rapid growth occurred from ages 3-6. As a validation of the developmental scaling approach, greater self-regulation was associated with better school readiness (math and reading skills) and fewer externalizing problems. Our multi-wave, multi-facet, multi-method, multi-measure, multi-rater, developmental scaling approach is the most comprehensive to date for assessing the development of self-regulation. This approach demonstrates that developmental scaling may enable studying development of self-regulation across the lifespan.

Lexical access speed and the development of phonological recoding during immediate serial recall.

A recent Registered Replication Report (RRR) of the development of verbal rehearsal during serial recall (Elliott et al., 2021) revealed that children verbalized at younger ages than previously thought (Flavell et al., 1966), but did not identify sources of individual differences. Here we use mediation analysis to reanalyze data from the 934 children ranging from 5 to 10 years old from the RRR for that purpose. From ages 5 to 7, the time taken for a child to label pictures (i.e. isolated naming speed) predicted the child's spontaneous use of labels during a visually-presented serial reconstruction task, despite no need for spoken responses. For 6- and 7-year-olds, isolated naming speed also predicted recall. The degree to which verbalization mediated the relation between isolated naming speed and recall changed across development. All relations dissipated by age 10. The same general pattern was observed in an exploratory analysis of delayed recall for which greater demands are placed on rehearsal for item maintenance. Overall, our findings suggest that spontaneous phonological recoding during a standard short-term memory task emerges around age 5, increases in efficiency during the early elementary school years, and is sufficiently automatic by age 10 to support immediate serial recall in most children. Moreover, the findings highlight the need to distinguish between phonological recoding and rehearsal in developmental studies of short-term memory.