The contribution of Visual Processing Speed to Visual and Auditory Working Memory in Early School Years
Although brain imaging indicates that the visually driven parieto-frontal network is the predominant neural network underlying working memory (WM) and aspects of visually driven working memory are apparent in early infancy before children develop verbal language, it remains unclear how the visual and auditory sensory systems contribute to WM development during early school years. Thus, the current study aimed to examine age-related changes in WM in children (n=100, 5 -7 years) employing visual and auditory verbal Digit Span tasks as the dependent variable measures and structural equation models to determine the predictive contribution of aspects of visual processing speed to WM. Cognitive processing speed was measured utilizing a simple visual inspection time (IT) task, a visual-verbal processing task (Rapid Automatic Naming (RAN) of objects), and a visuo-motor game-like iPad application, (the ‘SLURP’ task). The key finding of this study was that both visual and auditory WM span improved significantly with age, though these children all showed better performance on auditory than visual WM tasks. Our results also showed that age related increases in speed of visual information processing contribute strongly to visual but not auditory WM development. Results of the current study are consistent with the notion that visual and auditory WM are dissociable cognitive domains that develop at differential rates as the child learns to read.
Keywords - Processing Speed, Sensory Processing, Children, Working Memory, Short-Term Memory, Visual Working Memory, Auditory Working Memory, Visuomotor Performance, Time Estimation