Speech processing and short term memory skills in preschoolers: Evidence from Greek-speaking children with and without speech sound disorders

Cognitive mechanisms such as short-term memory (STM) are considered to relate to speech development, yet the extent of potential limitations in children with speech sound disorders (SSD) is unknown and the nature of the relationship is debatable. The present paper explores the development of speech input and output processing skills along with STM skills in Greek-speaking children with SSD and typically developing (TD) controls. Potential relationships in performance between tasks that require phonological processing are explored. Participants with SSD aged 5;1-6;2 years (n = 30) and TD controls aged 5;1-5;11 years (n = 100) were monolingual Greek-speaking children. Speech processing skills and phonological storage were assessed as follows: (1) Input processing: a nonword auditory discrimination task was used to assess phoneme discrimination skills. Stimuli comprised 24 pairs of nonwords consisting of the same number of phonemes (2-7 phonemes) and syllables (1-3 syllables). (2) Output processing: a nonword repetition task was used to assess speech production skills. Stimuli comprised 24 nonwords of varying length (2-5 syllables). (3) STM: a task of immediate verbal recall was used to assess phonological storage. Stimuli comprised a chunk of five words; each word (2-4 syllables long) was semantically unrelated to others. The results showed that TD children outperformed children with SSD in all tasks; a significant correlation between performance in nonword repetition and immediate verbal recall was found for TD children. There were no significant correlations between performance on nonword auditory discrimination with nonword repetition or with immediate verbal recall for TD children or children with SSD.