LangCog Seminar - Becky Baxter

Background: Individuals with Down syndrome experience difficulties with a range of speech and language skills including; speech (e.g., Burgoyne et al., 2021), vocabulary acquisition (e.g., Berglund et al, 2001; Stoel-Gammon, 2001), pragmatic language skills (e.g., Abbeduto, 2008) and syntax (e.g., Frizelle et al., 2018), particularly morphosyntax (e.g., Chapman et al, 1998; Laws & Bishop, 2003).

Research questions: This study evaluated the effectiveness of an oral language intervention developed for children with Down syndrome targeting the regular simple past tense. In addition, any factors associated with intervention gains were explored.

Methods 52 children with Down syndrome (aged 7-11) attending mainstream schools in Hampshire, UK and surrounding borders were recruited. A randomised control trial (RCT) was conducted to measure progress following a language intervention. Participants were allocated into two groups: (1) an intervention group and (2) a delayed intervention group who received the intervention after a 14 week wait period. Children were assessed at three time points: pre-intervention (time 1), after 10-weeks of intervention (time 2), and after the delayed intervention group had received the intervention (time 3). The intervention was delivered by trained teaching assistants who were visited fortnightly by a speech and language therapist and sessions were scored on a scale of 1-4 on the following five criteria; organisation, tailoring to individual needs, compliance, behaviour, enjoyment.

Results: There were no differences between the two groups at time 1. At time 2, the intervention group had made significantly greater gains on standardised measures of regular simple past tense. Generalisation was seen on bespoke measures including matched untaught verbs and use in story retell. Effects did not transfer to other grammatical rules. A number of baseline measures were associated with gains on the intervention including non-verbal mental age, expressive language, word reading and letter sound knowledge. There was a significant correlation between TA mean scores and the intervention gains.

Conclusion: This study shows that children with Down syndrome, who display severe language difficulties, can be taught to use the regular simple past tense. Furthermore, teaching assistants were able to effectively deliver intervention targeting morphosyntax following training, supervision and guidance.