Using dual coding theory as an instructional model to remediate dyslexics: Neuroscientific and behavioral results

Using dual coding theory as an instructional model to remediate dyslexics: Neuroscientific and behavioral results

First Author: Angelica Benson -- Lindamood-Bell Learning Processes
Additional authors/chairs: 
Paul Worthington
Keywords: Theories of learning to read, Dyslexia, Intervention, outcome assessment, Process Evaluation
Abstract / Summary: 

Purpose
This paper investigates the comparative neuroscientific and behavioral reading intervention outcomes from a series of studies on individuals with dyslexia. The intervention is based on the idea that learning to read is best understood and addressed as an integration of sensory representations (sounds/phonemes and visual/graphemes) through instructional processes – a model consistent with Dual Coding Theory (DCT).
Method
Subjects in 4 separate studies received diagnostic assessments measuring symbol imagery, phonemic awareness, word attack, word recognition, spelling, reading rate, accuracy, fluency and comprehension. This was followed by one-to-one intensive reading instruction that focused on developing mental representations of letters and sounds within words. After an average of 120 hours of instruction, delivered 2-4 hours daily, 5 days a week, posttests were administered.

Study 1 included pre and post intervention brain imaging measures in adults with dyslexia (Eden et al, 2004). Studies 2, 3, 4 included pre and post intervention brain imaging measures in children with dyslexia (Krafnick, Flowers, Napoliello, & Eden, 2011), (Romeo et al, 2017), (Donnelly, Huber, & Yeatman, 2019).
Results
All studies revealed significant improvements on measures of phonemic awareness (auditory), and sight word reading (visual), as correlated with those areas in the brain classically associated with those functions. Significant positive gray matter volumetric (GMV) changes and significant enhanced white matter conductivity changes were noted, all with significant positive group effects in reading.
Conclusions
These neuroscientific and behavioral results reveal a positive direction in addressing the needs of dyslexics using an intervention based on DCT and suggest that a diagnosis of dyslexia need not be one of a permanent nature.