Working memory span in Persian-speaking children with speech sound disorders and normal speech development

Area of Science:

• Child language development
• Speech-language pathology
• Cognitive psychology

Background:

• Speech sound disorder (SSD) affects phonological processing and can impact cognitive functions like working memory.
• Working memory, comprising phonological loop and central executive components, is crucial for language acquisition and processing.
• Preschool-aged children are a critical period for both speech and cognitive development.

Purpose of the Study:

• To compare working memory span in Persian-speaking preschool children with SSD and their typically developing (TD) peers.
• To investigate the relationship between SSD severity and specific working memory tasks: Non-Word Repetition (NWR), Forward Digit Span (FDS), and Backward Digit Span (BDS).

Main Methods:

• A case-control study involving 35 children with SSD and 35 age- and sex-matched TD children (48-72 months).
• Assessment of working memory components: phonological loop (NWR, FDS) and central executive (BDS).
• SSD severity was determined using Percentage of Correct Consonants (PCC).

Main Results:

• Children with SSD demonstrated significantly weaker performance on all working memory tasks compared to TD children (p < 0.001).
• Within the SSD group, varying severity levels showed significant differences in NWR and FDS performance (p < 0.001), but not BDS (p > 0.05).
• PCC scores correlated with NWR, FDS, and BDS in TD children, and with NWR and FDS in children with SSD.

Conclusions:

• Working memory skills are significantly impaired in preschool children with SSD compared to their TD peers.
• The phonological loop, assessed by NWR and FDS, is more affected by SSD severity than the central executive component (BDS).
• These findings highlight the intricate link between speech sound production and working memory capacity in early childhood.