Observational StudyOptimizing Feedback-based Learning in Children With Developmental Language Disorder

This project aims to optimize a critical but understudied ingredient of language intervention provided to children with developmental language disorder (DLD) - feedback. The project will bridge a gap between previous findings in our lab of inefficient feedback processing in DLD and clinical practice by identifying the conditions under which feedback-based learning can be improved in DLD. The investigators hypothesize that the effectiveness of feedback can be significantly enhanced for children with DLD when it is tailored to their unique learning strengths. The rationale for this project is based on evidence that feedback-based learning can be improved by enhancing the dominance of an intact learning system. The project will achieve its aim by manipulating (1) the timing of the feedback (immediate vs. delayed) and (2) the level of the learner's involvement in error correction dictated by feedback (active vs. passive correction). Aim 1 will determine the effect of manipulating feedback timing on learning in 140 school-age children (8-12 years) with DLD. While immediate feedback is processed by the striatum, which is also implicated in implicit learning, delaying the feedback by a few seconds shifts feedback processing to the mediate temporal lobe (MTL)-based declarative learning system. Evidence that delaying feedback improves learning in DLD would support the hypothesis of the implicit deficit theory that intervention should capitalize on declarative learning mechanisms. The project will test a novel alternative feedback-learning parity hypothesis whereby feedback-based learning is optimized when the timing of the feedback is aligned with the dominant learning system at a given time (i.e., immediate feedback during striatal-based probabilistic learning; delayed feedback during MTL-based declarative learning). Within the same group of children, Aim 2 will compare feedback-based learning in children with DLD when feedback (a) prompts active self-correction or (b) passively exposes learners to error corrections (corrective recast). Children will engage in two nonword-object paired-associate learning tasks. In one task, feedback will promote active self-correction, which is in line with declarative learning. In the other task, feedback will passively expose the learner to corrective feedback in a manner consistent with teaching approaches aiming at reducing awareness of errors. The project will determine whether children with DLD learn better when feedback prompts self-correction or when they are exposed to passive corrections. Electrophysiological measures will indicate whether passive corrections (corrective recast) are processed as negative feedback by children with DLD. For both aims, behavioral indicators of response to feedback will be complemented by electrophysiological measures of feedback processing that can determine the involvement of the striatum and MTL brain systems during the learning process. This work is scientifically and clinically significant because elucidating what manipulations optimize feedback-based learning will enhance our understanding of the impaired learning mechanism in DLD and will provide clinical guidance on what type of feedback to use during an intervention.