Manipulating Linguistic Complexity to Improve Child Language Treatment Outcomes
Condition: Language Development Disorders; Speech Sound Disorder
MeSH terms: Language Development Disorders; Speech Sound Disorder
Study type: Interventional

Summary: 
      Phonological disorder (PD) and specific language impairment (SLI) directly impact a child's
      ability to communicate and are among the most prevalent developmental disorders. The proposed
      experiments manipulate the complexity of treatment targets to identify the most efficacious
      treatment approaches for English- and Spanish-speaking children aged 3 to 6 years who present
      with these disorders. This research will reveal the nature of interactions between sound and
      structure in language for these children and will have significant implications for a unique
      approach to target selection when treating persistent phonological and grammatical
      difficulties in children with PD, SLI, or both.
    

Detailed description: 
      Specific Aim 1: To evaluate relative effects and effectiveness of phonological complexity of
      treatment stimuli on generalization learning following speech-sound treatment of
      Spanish-speaking children with PD. Experiment 1 is an across-subjects evaluation of
      phonological complexity of treatment words on speech-sound generalization learning in
      Spanish-speaking children with PD. Children will receive speech-sound treatment in Spanish on
      words that are phonologically simple or complex. It is predicted that the phonologically
      complex cluster condition will lead to greater generalization as compared to the singleton
      condition in the children's speech sound use. Specifically, it is assumed that greater
      generalization learning will occur following treatment on consonant clusters than following
      treatment on singletons. These predictions will be evaluated based on the children's
      posttreatment accuracy on the Generalization Probe.

      Specific Aim 2: To evaluate relative effects and effectiveness of phonological and
      morphological complexity of treatment verb stimuli on generalization learning following
      speech-sound treatment of English-speaking children with PD and PD-SLI. Experiment 2 is an
      across-subjects evaluation of phonological and morphological complexity of treatment words on
      speech-sound generalization learning in children with PD and those with PD-SLI. Children will
      receive speech-sound treatment in English on verbs that are morphologically simple or complex
      in phonologically simple or complex verbs. It is predicted that the phonologically complex
      cluster condition will lead to greater generalization (vs. the singleton condition) in the PD
      and PD-SLI children's sound systems, and that this effect will be enhanced in a
      morphologically complex bi-morphemic context. It is assumed that treatment on final clusters
      will generalize to final singletons and clusters, whereas treatment on final singletons will
      generalize to final singletons only. Further, it is predicted that treatment in a
      bi-morphemic context will generalize to mono-morphemic contexts, but not vice versa. Finally,
      although it is predicted that the cluster advantage will be observed in both populations, it
      is possible that, for the PD-SLI children, the bi-morphemic context may introduce too much
      new information (new phonological structure and new morphological structure) that may inhibit
      generalization learning for those children due to their reduced accuracy in both phonology
      and morphology. These predictions will be evaluated based on the children's post-treatment
      accuracy on the Generalization Probe.

      Specific Aim 3: To evaluate relative effects and effectiveness of phonological complexity of
      bi-morphemic treatment verb stimuli on generalization learning following morpheme treatment
      of English-speaking children with SLI and PD-SLI. Experiment 3 is an across-subjects
      evaluation of phonological complexity of bi-morphemic treatment words on morpheme
      generalization learning in children with SLI and those with PD-SLI. Children will receive
      morpheme treatment in English on the third-person singular (3rdSg) morpheme "-s" in
      phonologically simple or complex verbs. It is predicted that the phonologically complex
      cluster condition will lead to greater generalization as compared to the singleton condition
      in the SLI and PD-SLI children's morpheme use. Specifically, it is assumed that greater
      generalization learning of the treated 3rdSg morpheme will occur following treatment on the
      morpheme in cluster contexts than following treatment in singleton contexts. Further, though
      it is predicted that the cluster advantage will be observed in both populations, it is
      possible that, for the PD-SLI children, the cluster context may introduce too much new
      information (new morphological structure and new phonological structure) that may inhibit
      generalization learning for those children due to their reduced accuracy in both phonology
      and morphology. These predictions will be evaluated based on the children's post-treatment
      accuracy on the Generalization Probe.

      This proposed research program will evaluate the influence of morpho-phonological interaction
      in the language of English and Spanish-speaking children with phonological disorder (PD),
      those with specific language impairment (SLI), and those children with co-occurring PD and
      SLI (PD-SLI) through manipulation of phonological and morphological complexity in the
      selection of treatment target words. The proposed research will 1) bridge linguistic theory
      with clinical treatment to identify ideal targets for generalization learning across
      populations, 2) focus on both morphology and phonology, which are known to interact in normal
      systems, and 3) define how these principles together impact on the management of disordered
      systems. Upon completion of the proposed work, the nature of morpho-phonological interactions
      within and across the clinical populations will be identified, and the role of
      (morpho-)phonological complexity in driving change following treatment will be delineated.

      The participants for the proposed study will include 10 Spanish-speaking children aged 3 to 6
      years with PD, and 36 English monolingual children between the ages of 4 and 6 years of age
      with PD (n = 12), SLI (n = 6), or co-occurring PD-SLI (n = 18). The participants will be
      recruited through schools and community organizations but will not be enrolled in any other
      speech/language services elsewhere. All participants will have typical intellectual, hearing,
      social-emotional, and neurological development, per caregiver report. Both male and female
      participants will be recruited, as will children from varied racial/ethnic backgrounds.

      This study employs a single-subject, staggered multiple-baseline design. Data will include
      caregiver-reported demographic data, scores on the standardized tests, digital recordings of
      participants' spontaneous language, Treatment Probes and Generalization Probes, computerized
      analyses of speech/language samples and probes, and transcribed responses from
      speech/language samples and probes. All such data will be collected following caregiver
      consent and child assent. Further, all data will be collected at the San Diego State
      University (SDSU) Speech-Language Clinic, with the exception of the caregiver report, which
      may be completed by the caregiver at home.

      Children who meet the inclusionary criteria will be classified as having PD, SLI, or PD-SLI,
      per those criteria. They will be assigned to a particular treatment condition. Spanish PD
      children will be assigned to one of two conditions of Experiment 1 (n= 5 per condition).
      English PD children will be assigned to one of four conditions of Experiment 2 (n=3 per
      condition) and SLI children will be assigned to one of two conditions of Experiment 3 (n=3
      per condition). PD-SLI children will be assigned to one of four conditions of Experiment 2
      (n=3 per condition) or one of two conditions of Experiment 3 (n=3 per condition). Following
      treatment condition assignment, specific treatment target stimuli will be identified for each
      child.

      The next set of procedures involve the following, with 1-hour sessions occurring three times
      weekly:

        -  Baseline testing phase, to include administration of the Generalization Probe (a minimum
           of three baselines per child);

        -  Treatment phase (maximum 18 sessions), to include

             -  Treatment Probe administered at the start of each session and

             -  Generalization Probe collected after 9 treatment sessions;

        -  Post-treatment testing phase to include Generalization Probe collected immediately
           following treatment, and at 2 weeks and 2 months posttreatment.

      Following treatment condition assignment, specific treatment target stimuli will be
      identified for each child. The next set of procedures involve the following, with 1-hour
      sessions two to three times weekly: Baseline testing phase, to include administration of the
      Generalization Probe (a minimum of three baseline sessions per child); Treatment phase
      (maximum 18 sessions), to include Treatment Probe administered at the start of each session
      and Generalization Probe collected after 9 treatment sessions; Post-treatment testing phase,
      to include Generalization Probe collected immediately following treatment, and at 2 weeks and
      2 months posttreatment. Following completion of the posttreatment testing, children will be
      dismissed from participation in the research program.

      Data from Treatment and Generalization Probes will reflect measures of the dependent
      variable. Treatment Probe data will be collected to document learning during treatment.
      Children's learning of the treated target (i.e., singleton or cluster for Experiments 1 and
      2, 3rdSg morpheme for Experiment 3) in treated words across all treatment sessions will be
      measured. This will be done via measures of percent accuracy on the treatment target in
      treated words produced during treatment sessions. Generalization data will be collected
      during pretreatment baseline sessions, after 9 treatment sessions, immediately following
      treatment, and at 2 weeks and 2 months posttreatment, and will consist of singleton and
      cluster accuracy and morpheme accuracy on the Generalization Probe. All the above
      speech/language samples will be orthographically transcribed and coded for morpho-syntax
      using Systematic Analysis of Language Transcripts (SALT), and phonetically transcribed, using
      broad notation of the International Phonetic Alphabet in Phon software by trained research
      assistants who are undergraduate and graduate students of speech-language pathology and/or
      linguistics. Unintelligible words will not be included in accuracy analyses, given that a
      target form cannot be determined for such productions. Generalization is operationally
      defined as greater than 10% increase in accuracy on the generalization data following
      treatment as compared to average baseline levels. Following completion of the post-treatment
      testing, children will be dismissed from participation in the research program. Referrals, if
      needed, for further speech/language services will be provided.
    

Intervention name(s): Phonological treatment; Morpheme treatment
Intervention type(s): Behavioral; Behavioral
Intervention description(s): The clinician will provide models, verbal and/or tactile cues, and/or conversational recasts of speech sound targets following the methodology of Gierut and colleagues. Up to 100 productions will be targeted per 1-hour session.; The clinician will provide models, verbal and/or tactile cues, and/or conversational recasts of targeted morphemes following the methodology of Plante and colleagues. A minimum of 50 productions will be targeted per 1-hour session.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: PHONOLOGY; MORPHOLOGY