Edith Cowan University Late Talkers Study: a statistical learning intervention for young children with late language emergence

Children that are late to acquire their first words are at high risk of ongoing language and developmental difficulties. This project aims to contribute to the body of research about the efficacy of parent-administered speech therapy, and to further evaluate the contributions of the 'ingredients' of therapy, such as dose and variability of input. Design This is a single subject (AB) (A = baseline and B = treatment) non-concurrent multiple baseline design, with replication across four participants. Protocol Each parent and child will attend: • A baseline assessment session, • An individual parent-training session • 8 group parent-training sessions • 3 video-observation sessions to assess treatment fidelity • A post-treatment assessment session Baseline Assessment Session The baseline assessment session will be performed within the four weeks prior to the intervention. It will take approximately 45 minutes and include: • An oral explanation of the study protocol, and a description of what parents and children will be asked to do • An OZI (Australian English Communicative Development Inventory) will be completed by parents to establish baseline language learning abilities • Two video recorded language samples, one with the parent and child and another with the child and a researcher. These will be used to corroborate the language survey results and to get a baseline of parent linguistic input. Initial individual parent-training session Parents will attend a one-hour individual parent-training session, within the four weeks prior to the intervention. This session will consist of: • Written and verbal information about the study objectives and rationale for the study to be explained by the clinicians • Parents to nominate vocabulary goals/words they would like their children to acquire during the course of treatment. • Demonstration of the child-directed language therapy technique with high dose and grammatical and physical variability by the clinicians • Parents will be instructed to conduct therapy twice per week for thirty minutes. During these sessions they will be aiming for as many presentations of the target word as possible, with a minimum of 64 doses. They will also be instructed to aim for high variability, both grammatical (different positions within a sentence) and physical (using different toys, materials). • Opportunities to practice by the parent, both in a simulated (without child) and real-life (with their child) contexts • Parents will be given information materials to take home which summarizes how to use language during the home treatment sessions. These will be created by the student Speech Pathologists and approved by Dr Meldrum and Ms Hunt before the sessions. These materials will contain activities and suggestions to promote high variability and high dose for the target words during the home treatment session. • Parents will complete a pre-treatment acceptability questionnaire Target and control word selection After all parents have completed the individual parent-training sessions, the research team will select 10 target and control word pairs (20 words in total) to be used for all the children. To be selected, the words will not be present in any of the children’s expressive vocabularies, but receptively known by them, as reported in the OZI collected at the individual training sessions. Where possible, words will be included which the families have nominated as possible targets. Word pairs will be matched as closely as possible based on grammatical category (noun, verb, adjective etc), semantic category (food, vehicles, clothing etc), number of syllables and item trajectories on the Stanford Wordbank Item Trajectories for the child’s age. Words will then be randomly allocated to target or control words and in treatment order. Control words will be used as part of the training process. Both control and target words will be tested each week, and in as an outcome in the final session. Parent group-training sessions Parents and children will attend 8 group training sessions, one per week. There will be a maximum of 4 dyads of parents and children per group. Each session will last no longer than an hour and will include: • Initial block of probes to assess production of all target and control words. Photos and spoken cloze phrases (e.g. what’s this?) will be provided in random order to elicit a spontaneous (i.e. not imitated) production. • Parents will be given an OZI to update, reporting their child’s use of any new words (not only target and control words) each week. • Home treatment diaries will be reviewed, which note how many home treatment sessions took place, the duration, and targets in order to determine adherence to protocol • The clinicians will nominate three target words to be treated in the home treatment sessions during the next week. • Parents will be instructed to conduct two sessions at home per week, each lasting approximately 30 minutes (during which they target the three target words). • The clinician will demonstrate at least five different activities to feature the target words and ensure physical variability. Activities relevant to the target word may include playing with toys, making craft and looking at books. Activities will be designed by the student Speech Pathologists and approved by Dr Meldrum and Ms Hunt before the session. • The clinician will demonstrate how to present the target word at least five different positions within an utterance (for grammatic variability). For example “That’s a duck! The duck is swimming in the pond. I want to pick up my duck and put him in his bed.” • Parents will be reminded that the goal is to provide a minimum of 64 exemplars of a word, using the demonstrated techniques as much as possible within the home treatment session. • Participants will be given opportunities to practice the activities and target word presentation with their child. • Clinicians will provide gentle, guided feedback and encouragement, always focusing on achieving the goal of high dose and variability of target words in parent-to-child language. This will be akin to published protocols of parent training for Speech Pathology and based on adult learning principals, such as "Exploring Input Parameters in an Expressive Vocabulary Treatment With Late Talkers" Alt, et al. (2020); "Systematic review of the literature on the treatment of children with late language emergence" Cable & Domsch (2011); and "Association of Parent Training With Child Language Development: A Systematic Review and Meta-analysis" Roberts et al., (2019) • Participants will be reminded to fill in the home treatment diary each time they conduct home treatment, recording the date, time spent, the target word and their perception of the experience (reasonableness). • Parents will be given opportunities to discuss and describe their experiences in giving the intervention to the other parents and the clinician. • Parents will be reminded to give no additional language intervention, other than the two 30-minute home sessions per week. If at any time the family cannot participate, due to illness or child non-compliance at the session, then the family will be invited to add a session to the intervention schedule (8 sessions in total are required). The parent and/or the child may refuse to attend at any time without penalty. If they wish to withdraw, they will be asked if they will allow their data to be used in analysis or if they wish to withdraw their data completely. Information will be obtained about the reasons for withdrawal if possible (if the parents are willing and contactable to do so), to inform the feasibility and acceptability evaluation of the program. Treatment fidelity sessions After each group training session, one family will remain and participate in a treatment fidelity session for approximately 30 minutes. Each family will participate in 2 treatment fidelity sessions across the course of the trial. At these sessions, the parent will be instructed to complete the intervention with their child as they would usually do at home. Only the parent and child will be interacting, with the clinician only observing and ensuring adequate videotaping. Parents will be instructed that this will count as one of the two home sessions to be conducted that week, to ensure that all children receive the same number of intervention sessions per week. The interaction will be videotaped with the aim of determining treatment fidelity. At a later time, the variability and dose of the target words will be measured, along with any child word productions and any production of the control words. Post-Treatment Assessments In the week after the group-training sessions have finished, participants and their parents will attend an individual post-treatment assessment, which will take approximately 45 minutes, and include the following activities: • A final OZI will be completed by parents • Two video recorded language samples, one with the parent and child and another with the child and a researcher to corroborate the language survey results and to measure parent linguistic input. • The Intervention Acceptability questionnaire will be completed in written format by the parents, and a semi-structured interview of parents views. • The Intervention Acceptability questionnaire will be completed in written format by the student clinician. Study Personnel Two final (4th) year Speech Pathology students will administer the intervention protocol (all clinician appointments listed above) under the direct supervision of Dr Meldrum and Ms Hunt who are both qualified Speech Pathologists. Location All appointments will take place at the School of Medical and Health Sciences, Edith Cowan University in Joondalup, Western Australia. Travel will be required by participants to this facility, and parking will be provided.