Frequency discrimination and non-lexical reading in children with auditory processing disorders: a preliminary study

Purpose: To explore the potential differential effect of auditory frequency discrimination (FD) difficulty on a range of reading and cognitive processes in children with Auditory Processing Disorders (APD). Methods: Sixteen children with APD (aged 7;5 to 10;2), eight with FD difficulty (FD-POOR group), and eight with age-appropriate FD (FD-TYPICAL group) were tested on measures of non-lexical and lexical reading, phonological processing (phonological awareness, phonological memory and rapid automatized naming), receptive language, auditory sustained attention, and executive function. Results: The results showed that children with poor FD experienced difficulty with tasks associated with non-lexical reading and phonological awareness. There were no significant differences between the groups on lexical reading, phonological memory and rapid automatized naming. Children with FD difficulty also showed poorer executive function. Specifically, they showed greater lag in reaction times (slower reaction times) on incongruent verses congruent trials on a modified Simon Task, indicating a larger Simon Effect. This suggests that these children were more affected by incongruency and showed poorer attention control. This finding was in the absence of significant differences in receptive language and auditory sustained attention. Conclusion: These findings support the notion that FD difficulty often co-exists with reading difficulty in children with APD. Extending the previous findings, the present results suggest that FD pertained largely with specific aspects of reading, namely the non-lexical reading process and phonological awareness. These findings are consistent with the current models of reading that non-lexical reading and phonological awareness are more dependent on AP abilities. Additionally, poorer executive function in children with poor FD support further investigation into the association between executive function, FD, and reading in children with APD.