The relation between complement understanding and computational skills: A random intercept cross-lagged panel model.

Understanding of the complement principle has been proposed as closely related to computational skills, but few studies have investigated their interrelations. The present longitudinal study attempted to clarify the picture by examining their potential cross-lagged relation. Fourth graders (n = 221) in Hong Kong received 3 cognitive assessments at intervals of 6 months, consisting of multiple measures of complement understanding, a nonverbal intelligence test, and a computational skills measure. A random intercept cross-lagged panel model revealed that complement understanding significantly predicted future computational skills, but the reciprocal prediction was nonsignificant. The findings provide empirical evidence supporting the close relation between complement understanding and computational skills and call for future endeavors to examine the interrelations between computational skills and understanding of other arithmetic principles. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Comorbidity between persistent reading and mathematics disabilities: The nature of comorbidity.

The current study aimed at investigating the comorbidity between reading disability (RD) and mathematical disability (MD) in a non-alphabetic language context. Over 1,900 Chinese first graders were screened on their reading and mathematics achievement twice. Children who scored consistently below the 10th percentile in reading and/or mathematics were identified as RD and/or MD respectively. A subsample of these children, together with a group of typically-achieving children, were further assessed on their cognitive capacities. Results suggested that while there were cognitive deficits that were specifically found in RD (shifting) versus MD (spatial working memory, inhibition, processing speed, visual attention) groups, deficits in naming speed was found in both RD and MD groups. The cognitive profile of the comorbid group was an additive combination of those of the two single LD groups. The findings suggest that RD and MD are two dissociable learning disabilities with distinct cognitive profiles. Effective screening and intervention can be developed based on the cognitive profiles of different disability groups.