Structural Relationship Between Cognitive Processing and Syntactic Sentence Comprehension in Children With and Without Developmental Language Disorder

Abstract

Purpose: We assessed the potential direct and indirect (mediated) influences of 4 cognitive mechanisms we believe are theoretically relevant to canonical and noncanonical sentence comprehension of school-age children with and without developmental language disorder (DLD).

Method: One hundred seventeen children with DLD and 117 propensity-matched typically developing (TD) children participated. Comprehension was indexed by children identifying the agent in implausible sentences. Children completed cognitive tasks indexing the latent predictors of fluid reasoning (FLD-R), controlled attention (CATT), complex working memory (cWM), and long-term memory language knowledge (LTM-LK).

Results: Structural equation modeling revealed that the best model fit was an indirect model in which cWM mediated the relationship among FLD-R, CATT, LTM-LK, and sentence comprehension. For TD children, comprehension of both sentence types was indirectly influenced by FLD-R (pattern recognition) and LTM-LK (linguistic chunking). For children with DLD, canonical sentence comprehension was indirectly influenced by LTM-LK and CATT, and noncanonical comprehension was indirectly influenced just by CATT.

Conclusions: cWM mediates sentence comprehension in children with DLD and TD children. For TD children, comprehension occurs automatically through pattern recognition and linguistic chunking. For children with DLD, comprehension is cognitively effortful. Whereas canonical comprehension occurs through chunking, noncanonical comprehension develops on a word-by-word basis.

Supplemental material: https://doi.org/10.23641/asha.7178939.

Figure 1.

Gillam–Evans–Montgomery structural equation model of the direct relationships between the exogenous latent variables of controlled attention (CATT) indexed by the manifest variables of auditory sustained attention (SusAtt), auditory attention switching (AttSW), fluid reasoning (FLD R) indexed by Leiter-R Figure Ground (Leiter FG), Leiter-R Sequential Order (Leiter SO), Leiter-R Repeated Patterns (Leiter RP), complex working memory (cWM) indexed by verbal working memory (WJ-AWM) and auditory working memory for tones (HI-LoW), and long-term memory language knowledge (LTM-LK) indexed by narrative language comprehension (TNL-REC) and narrative language expression (TNL-EXP); a propensity score (PROP S) control; and the endogenous observed variables canonical sentence comprehension accuracy (CANACC) and noncanonical sentence comprehension accuracy (NOCANACC). Path standardized YX estimates for the typically developing and developmental language disorder groups are shown next to arrows. Leiter-R = Leiter International Performance Scale–Revised.

Figure 2.

Structural equation model of fluid reasoning (FLD R) mediating the relationships between the exogenous latent variables of controlled attention (CATT), complex working memory (cWM), and long-term memory language knowledge (LTM-LK); a propensity score (PROP S) control; and the endogenous observed variables canonical sentence comprehension accuracy (CANACC) and noncanonical sentence comprehension accuracy (NOCANACC). Path standardized YX estimates for the typically developing and developmental language disorder groups are shown next to arrows. Insignificant direct paths from predictor variables to CANACC and NOCANACC are not represented.

Figure 3.

Structural equation model of controlled attention (CATT) mediating the relationships between the exogenous latent variables of fluid reasoning (FLD R), complex working memory (cWM), long-term memory language knowledge (LTM-LK); a propensity score (PROP S) control; and the endogenous observed variables canonical sentence comprehension accuracy (CANACC) and noncanonical sentence comprehension accuracy (NOCANACC). Path standardized YX estimates for the typically developing and developmental language disorder groups are shown next to arrows. Insignificant direct paths from predictor variables to CANACC and NOCANACC are not represented.

Figure 4.

Structural equation model of long-term memory language knowledge (LTM-LK) mediating the relationships between the exogenous latent variables of fluid reasoning (FLD R), controlled attention (CATT), complex working memory (cWM); a propensity score (PROP S) control; and the endogenous observed variables canonical sentence comprehension accuracy (CANACC) and noncanonical sentence comprehension accuracy (NOCANACC). Path standardized YX estimates for the typically developing and developmental language disorder groups are shown next to arrows. Insignificant direct paths from predictor variables to CANACC and NOCANACC are not represented.

Figure 5.

Gillam–Evans–Montgomery structural equation model of complex working memory (cWM) mediating the relationships between the exogenous latent variables of fluid reasoning (FLD R), controlled attention (CATT), long-term memory language knowledge (LTM-LK); a propensity score (PROP S) control; and the endogenous observed variables canonical sentence comprehension accuracy (CANACC) and noncanonical sentence comprehension accuracy (NOCANACC). Path standardized YX estimates for the typically developing and developmental language disorder groups are shown next to arrows. Insignificant direct paths from predictor variables to CANACC and NOCANACC are not represented.