The phonological memory profile of preschool children who make atypical speech sound errors

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.

Sequencing Deficits and Phonological Speech Errors, But Not Articulation Errors, Predict Later Literacy Skills

PURPOSE

Speech sound disorder (SSD) in conjunction with a language disorder has been associated with poor literacy acquisition; however, no study has evaluated whether articulation, phonological, or sequencing skills are differentially related to reading skills. Therefore, this study examined the relationship between speech error types at ages 5-6 years and literacy at ages 7-9 years. Phonological errors were hypothesized to predict phonological awareness (PA) and literacy even while accounting for other speech error types and language skills.

METHOD

One hundred twenty-three children, 86 with a history of speech impairment, completed a battery of speech, language, and literacy tests at ages 5-6 years and again at ages 7-9 years. Speech production at ages 5-6 years was analyzed, and indices of articulation errors, phonological errors, and sequencing deficits were obtained. The relationships of these error types to concurrent language and preliteracy skills and to later literacy outcomes were assessed.

RESULTS

As expected, phonological, but not articulation, errors at ages 5-6 years predicted concurrent PA and letter knowledge, as well as literacy at ages 7-9 years, even while accounting for language skills. Surprisingly, of all the error types, sequencing deficits showed the strongest relationship with PA (ages 5-6 years) and literacy (ages 7-9 years).

CONCLUSIONS

These results suggest that some components of SSD uniquely predict preliteracy and literacy skills, even when controlling for language ability. Future investigations should examine further the association between sequencing deficits and literacy skills, test whether observed relationships hold at younger ages, and evaluate the efficacy of integrating literacy interventions into speech therapy to reduce later reading difficulties.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19624020.

Differentiating phonological delay from phonological disorder: Executive function performance in preschoolers

BACKGROUND

The conversational speech of most children can be understood by people outside the family by the time they reach 4 years. However, for some children, speech sound disorders (SSDs) persist into their early school years, and beyond, despite adequate hearing, oromotor function, and language learning opportunities. One explanation for children's SSDs are domain-general cognitive-linguistic deficits that impair the child's ability to correctly derive rules governing how speech sounds legally combine to form words in a specific language.

AIMS

To explore whether there are differences in performance on executive function tasks between children who make speech errors characteristic of phonological delay and those who make speech errors characteristic of phonological disorder.

METHODS & PROCEDURES

Twenty-six children aged from 3;6 to 5;2 (13 with phonological delay and 13 with phonological disorder), matched pairwise for age and sex (nine males), were assessed on tasks measuring cognitive flexibility (rule abstraction and cognitive shift) and phonological working memory.

OUTCOME & RESULTS

For the cognitive flexibility tasks, the performance of children with phonological delay was significantly better than that for children with phonological disorder, but there were no group differences for the phonological working memory task.

CONCLUSIONS & IMPLICATIONS

Children with phonological disorders might benefit from intervention programmes that incorporate training in cognitive flexibility.

WHAT IS ALREADY KNOWN ON THE SUBJECT

Children with phonological delay and phonological disorder comprise the two largest SSD subgroups that present to speech-language therapy clinics. Evidence suggests domain-general cognitive processes (e.g., phonological working memory, ability to revise faulty underlying representations, rule abstraction, and cognitive shift) influence phonological development. Differences between the two subgroups in the types of speech errors, linguistic abilities, developmental trajectories, and responses to intervention have been reported, yet little is known about the underlying cognitive-linguistic deficits.

WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE

The results of this study suggest that children with phonological delay and phonological disorder have distinct patterns of performance on executive function tasks: Children with phonological disorder showed deficits in domain general rule-abstraction and cognitive shift when compared to children with phonological delay. WHAT ARE THE POTENTIAL OR ACTUAL CLINICAL IMPLICATIONS OF THIS WORK?: The findings draw attention to: (1) the importance of differential diagnosis of phonological delay and phonological disorder; (2) the role of domain-general cognitive processes in explaining why children make particular types of errors; and (3) the need to develop innovative and tailored intervention techniques that target specific underlying deficits.

Executive functions in Persian-speaking preschool children with speech sound disorders and comparison with their typically developing peers

This study aimed to compare working memory, inhibitory control, and cognitive flexibility, the core components of executive functions, among two prevalent subtypes of preschool children with speech sound disorder, i.e., phonological delay (n = 16) and consistent phonological disorder (n = 15), and a group of typically developing children (n = 18). The correlation between executive function components and the accuracy of speech sound production were also investigated. Nonword repetition task and syllable repetition task were used to evaluate the phonological loop of working memory. Backward digit span was administered to examine the central executive of working memory. Cognitive flexibility was assessed using the second selection of the flexible item selection task and inhibitory control using Stroop-like and Go/No-Go tasks. The percentage consonants correct was applied to calculate the accuracy of speech sound production. Results of a one-way multivariate analysis of covariance revealed statistically significant differences between groups in the combined dependent variables after controlling for age (F(14, 80) = 17.289, p < .001, Pillai's trace = 1.503, partial ηƞ² = .752). Typically developing children outperformed in all measurements of executive functions than both speech sound disorder subgroups. Moreover, children with phonological delay performed better in nonword repetition and corrected responses of Stroop-like than consistent phonological disorder group. All executive function measurements also correlated with speech sound production. The results of the present study highlight the importance of including domain-general cognitive skills in current assessment protocols for children with phonological delay and consistent phonological disorders.

The Role of Executive Function in Developmental Stuttering

Developmental stuttering is a complex disorder and children who stutter form a heterogeneous group. Most contemporary researchers would agree that multiple factors, including those associated with linguistic, motor, sensory, and emotional processes, are likely involved in its development and/or maintenance. There is growing evidence, however, that cognitive processes also play a role. In this article, we briefly review behavioral and parent-report studies of executive function in children who stutter, the findings of which have generally suggested that these skills may be challenging for at least some children who stutter. We then consider how deficits in executive function could provide an explanatory account for not only the multifactorial nature of developmental stuttering but also the considerable amount of variability that exists among individuals who stutter.

Speech development in preschool children: evaluating the contribution of phonological short-term and phonological working memory

Emerging evidence suggests domain-general processes, including working memory, may contribute to reduced speech production skills in young children. This study compared the phonological short-term (pSTM) and phonological working memory (pWM) abilities of 50 monolingual English-speaking children between 3;6 and 5;11 with typical speech production skills and percentage consonant correct (PCC) standard scores of 12 and above (n = 22) and typical speech production skills and PCC standard scores of between 8 and 11 (n = 28). A multiple hierarchical regression was also conducted to determine whether pSTM and/or pWM could predict PCC. Children with typical speech production skills and PCC standard scores of 12 and above had better pWM abilities than children with typical speech production skills and PCC standard scores of between 8 and 11. pSTM ability was similar in both groups. pWM accounted for 5.3% variance in overall phonological accuracy. Implications of phonological working memory in speech development are discussed.

Validation of Dodd's Model for Differential Diagnosis of childhood speech sound disorders: a longitudinal community cohort study

AIM

Dodd's Model for Differential Diagnosis is one of the available clinical diagnostic classification systems of childhood speech sound disorders. Yet we do not understand the validity of this system beyond clinical samples, precluding its application in epidemiological or population-based research. This study aimed to determine the prevalence of subgroups of speech sound disorders in a community sample, relative to past clinical samples, in children speaking standard Australian English.

METHOD

We examined speech development in a community-ascertained sample of children at 4 years (n=1607). Inclusion for speech sound disorder was a score of less than or equal to 1 standard deviation on a standardized speech test, and/or research assistant concern, and/or three or more speech errors on sounds typically acquired by 4 years. Dodd's model was then applied to 126 children.

RESULTS

Data revealed proportions of children across Dodd's diagnostic subgroups as follows: suspected atypical speech motor control (10%); inconsistent phonological disorder (15%); consistent atypical phonological disorder (20%); phonological delay (55%); and articulation disorder alone (0%). The findings are in line with known prevalence of these subgroups in clinical populations.

INTERPRETATION

Our findings provide additional support for speech-language pathologists to use this system in clinical practice for differential diagnosis and targeted intervention of speech sound disorders in children.

WHAT THIS PAPER ADDS

Dodd's Model for Differential Diagnosis is the first classification system of speech sound disorders to be applicable to both clinical and community cohorts.

Articulation or phonology? Evidence from longitudinal error data

Children's speech difficulties can be motor (phone misarticulation) or linguistic (impaired knowledge of phonological contrasts and constraints). These two difficulties sometimes co-occur. This paper reports longitudinal data from the Early Language in Victoria Study (ELVS) at 4 and 7 years of age. Of 1494 participants, 93 made non-age appropriate speech errors on standardised assessments at 4 years, and were able to be reassessed at 7 years. At 4 years, 85% of these children only made phonological errors, 14% made both articulation and phonological errors and one child only made articulation errors (a lateral lisp). In total, 8 of 13 children making both articulation and phonological errors at 4 years had resolved by 7 years. Unexpectedly, eight children who had demonstrated articulation of fricatives at 4 years, acquired distorted production of ≥ 50% of occurrences of/s, z/ by 7 years. In total, then, 22 children (24% of children with speech difficulties) made articulatory errors at one or both assessments. Case data for all children are presented. Theoretical and clinical implications are considered.