Speech intervention for preschoolers with cleft palate using principles of motor learning

This is an initial study to apply speech intervention using the principles of motor learning to active and passive cleft type speech errors in preschool children aged 3-6 years. It is an alternating treatment single subject design with multiple baselines across participants and behaviours over two treatment phases. Two treatment phases, phase I and phase II, will be conducted twice weekly for eight weeks. A 4 week maintenance phase will follow each treatment phase. A final assessment will be administered 4 weeks after the final treatment session in phase II. The total study duration will be 28 weeks. The pre/post-treatment assessment and treatment in the study will be conducted by Certified Practising Speech Pathologists experienced in working with young children. Treatment sessions will go for 45-60 minutes. Each participant will be treated by the same speech pathologist throughout. There is no requirement for any practice outside of the twice-weekly speech therapy sessions. Parents/carers will attend all the sessions with the participant. Pre and post assessments and treatment will be conducted in the speech therapy clinic at: Sydney Children’s Hospital, Randwick or Communication Disorders Treatment and Research Clinic (CDTRC), The University of Sydney or the Canberra Hospital. Therapy speech targets A set of individualised speech targets will be selected for each participant in the study. Targets will be based on the speech sound errors identified during pre-treatment assessment using the results from the standardised assessment and the cleft speech assessment. A set of 3-6 treatment words that correspond with each selected target will be chosen as treatment items. These treatment items will be presented on picture cards that are age appropriate and engaging for the participants. Treatment Phases Each participant will attend two phases of twice weekly treatment sessions for eight consecutive weeks in each phase. Phase I will address either active or passive errors and will be alternated for phase II. Each treatment session will contain a pre-practice and practice component. The principles of motor learning that will be used to guide treatment are: *Practice Amount: more practice facilitates better learning than less practice *Practice Schedule: random practice facilitates better learning than blocked practice *Feedback Type: knowledge of results facilitates better learning than knowledge of performance *Feedback Frequency: reduced frequency feedback facilitates better learning than high frequency feedback A therapy manual will be created to guide the practice and feedback of the treatment sessions and data will be collected on both the participants’ practice attempts and the feedback given by the speech pathologist. Treatment items will be practiced during a series of age appropriate play based activities and educational games that have been carefully selected and/or designed as they directly relate to the participants’ targets and/or facilitate many productions of the treatment word. The participant will be presented with picture cards (that represent at word or phrase) and be asked to produce the words. Pre-practice The intention of the pre-practice component of a session is to prepare the participant for practice and is where the correct production will be taught and feedback that provides qualitative information and/or sensory information (e.g. you can feel your nose move when you say ‘mmmm’) is given to facilitate learning of the target production. This feedback is known as knowledge of performance feedback (KP) and is used in the treatment of motor speech disorders. An example of KP feedback could be ‘you said that using the back of your mouth sound’. Practice In the practice component of treatment, the treatment items are practiced and feedback is given. *Practice Amount: 100-120 practice attempts at the treatment items will be achieved each session. *Practice Schedule: Practice will be randomised and varied across treatment items to facilitate better learning and retention. *Feedback Frequency: Feedback will be given at a reduced frequency of 60%. Feedback will be delivered with fading feedback throughout sessions and across sessions over time. Therefore, feedback will be given at 100% for the entirety of the first session but gradually reduced until it is rarely used in the final sessions, resulting in feedback being given at a reduced rate of 60% throughout the study. *Feedback Type: Knowledge of results feedback (KR), whether a sound was right or wrong will be given in the practice. Control and generalization probes Single case experimental design methodology dictates that measurement of the target of intervention should be made repeatedly and frequently across all phases of the study. Therefore, a series of control and generalisation probe items will be used in baseline, follow-up and throughout treatment to calculate change in behaviour, monitor retention, learning and generalisation. Control items are a set of untreated words that are similar to the treatment words and generalisation items will include a set of words that include the untreated cleft errors (active or passive) and any untreated and unrelated developmental speech errors. The control and generalisation probe will be administered at each baseline session, at follow-up assessment and at the beginning of every third treatment session: they will be administered at treatment sessions 3, 6, 9, 12, and 15. The procedure to collect the probe items during baseline and treatment sessions is the same. The speech pathologist will present the child with a picture card and ask the child to name the picture, if they can not name the picture the participant will be encouraged to imitate it. The probe items will be delivered randomly. Blinding, reliability and fidelity All pre/post assessment, probes and treatment sessions will be video recorded. All probes will be recorded on high quality headset audio. All blinding is important where perceptual judgement is used in measuring outcomes. All control and generalisation probes will be assessed by independent speech pathologist/s recruited from the University of Sydney, who has no prior information regarding the treatment approach, design and hypothesis, and is blinded to the participant, treatment, session and phase. To ensure reliability of the perceptual judgement of response accuracy, inter and intra-rater reliability will be established. A randomly selected 10% of all trials across all the participants in the study will be rated by a qualified speech pathologist who is blinded to the treatment type and phase. Each speech pathologist who provides intervention will intra-rate a randomly selected 10% of the trials that they collected. In order to ensure fidelity of the intervention, a random selection of 10% the video recordings will be randomly analysed, rated and evaluated for reliability by members of the project team.