Implicit Learning in Preschool Children with and without Developmental Language Disorder

Abstract

The study below was designed to compare implicit learning in fifty-two preschool-aged children with and without developmental language disorder (DLD) to test the Procedural Deficit Hypothesis (PDH). The PDH claims that procedural memory, the basis of implicit learning, is the main impairment in DLD. Using a computer-based program to conduct sound-meaning-mapping tasks, we asked children to select one of two images according to the corresponding sound they heard. After all the participants were tested, an additional cue was found in the experiment that impacted the data. Instead of the children attuning to the sounds to depict the correct answer, the children picked up on an unintended visual cue: the target image tended to alternate from one side to another. Both children with DLD and TLD showed implicit learning of the visual alternation, in contradiction to the PDH. We relate these findings to the debate over the PDH and alternative hypotheses regarding the etiology of DLD.