Samuelsson et al. (2011)

NATURE OF PROSODIC DISORDERS

ANALYSIS FORM

 

Key:

 

NA = not applicable

P = Participant

pmh = Patricia Hargrove, blog developer

SLI = Specific Language Impairment

TD = Typically Developing

 

 

SOURCE: Samuelsson, C., Reuterskiöld, C., Nettelblatt, U., & Sahlén, B. (2011.) Production and perception of metrical patterns in Swedish children with language impairment. Logopedics Phonatrics Vocology, 36, 1-11.

 

REVIEWER(S): pmh

 

DATE: June 6, 2015

ASSIGNED GRADE FOR OVERALL QUALITY:  B (The highest possible grade based on the design of the investigation was B+.)

 

POPULATION: Specific Language Impairment (SLI), Swedish; Children

 

PURPOSE: To investigate the perception and production of metrical patterns in Swedish children diagnosed with language impairment.

 

INSIGHTS ABOUT PROSODY:

  • Swedish children with SLI more frequently omitted unstressed syllable than TD peers.
  • There may be 3 subgroups of prosody among children with SLI:

– stronger perception/comprehension than production/imitation,

– stronger production/imitation than perception/comprehension, and

– equivalent production/imitation and perception/comprehension.

 

 

  1. What type of evidence was identified? Prospective, Nonrandomized Group Comparison Design
  1. Group membership determination:
  • If there were groups of participants, were members of groups matched? Yes
  • The matching strategy involved selecting participants in the two groups were close in age (preschoolers.)
  1. Was participants’ communication status concealed?
  • from participants? No
  • from assessment administrators? Unclear
  • from data analyzers? Unclear

                                                                    

 

  1. Were the groups/participants adequately described? Yes

How many participants (Ps) were involved in the study?

  • total # of participants: 52
  • was group membership maintained throughout the experiment? Yes
  • # of groups: 2
  • List names of groups: SLI and typically developing (TD)
  • # of participants in each group: SLI = 27 (but see genders- p.4, reported 28 Ps); TD = 25

           

– The following variables controlled:              

  • cognitive skills: at least 78 nonverbal IQ (SLI); teacher reported normal development (TD)
  • language skills: SLI Ps were diagnosed with language impairment by a Swedish speech-language pathologist (SLP)
  • educational level of clients: Preschool
  • hearing: both groups passed a pure tone screening (25dB at 500, 1000, 2000, and 4000 Hz)

– The following variables were described:

  • age: mean age = 4:10 (TD); mean age = 5:4 (SLI)
  • gender: 10f; 18m (SLI); TD not reported

 

– Were the communication problems adequately described? Yes

  • disorder type:

     – 50% of the SLI group was diagnosed with severe language impairment in all domains of language

– 25% of the SLI group was diagnosed with moderate, expressive language impairment, particularly with respect to grammar and phonology

– 25% of the SLI group was diagnosed with mild phonological impairment

 

 

  1. What were the different conditions for this research?
  • Subject (Classification) Groups? Yes, there were 2 groups: SLI and TD
  • Experimental Conditions? No
  • Criterion/Descriptive Conditions? Yes, there were 3 tasks, all of them were in Swedish:
  • Imitation of phrases that differed on the placement of stress on the verb particle or on the prepositional phrase (iambic vs trochaic stress.) The examiner provided pictures to support the different sentences.
  • Comprehension task in which the participant (P) hears a direction and points to the appropriate picture of a set of 3 (2 contrasting sentences and a foil). The directions were identical sentences that differed only in the placement of stress on the verb particle or on the prepositional phrase (iambic vs trochaic stress.)
  • Imitation of phrases with an indefinite article (before the stressed syllable) or a definite form of a noun (after the stressed syllable. This contrasted differed iambic vs trochaic stress. The examiner provided pictures to support the different sentences.

 

  1. Were the groups controlled acceptably? Yes

 

 

  1. Were dependent measures appropriate and meaningful? Yes
  • The dependent measures were

Dependent Measure #1: Overall number of unstressed syllables omitted across all tasks

Dependent Measure #2: Proportion of prestressed syllables omitted in content words versus the proportion of omitted copulas

Dependent Measure #3: Comparing the same morpheme in different positions (stressed versus unstressed) and with different functions (verb particle versus preposition)

Dependent Measure #4: Relative strength of performance on imitated versus comprehension tasks concerned with phrasal stress.

Dependent Measure #5: Performance of Groups from measure 4 on

  • imitation of total unstressed syllables
  • perception of total unstressed syllables
  • imitation of prestressed syllables

Dependent Measure #6: Relationship between linguistic variables and nonverbal IQ among SLI Ps

  • All the dependent measures were subjective:.

 

  • None of the dependent/ outcome measures were objective?

                                         

 

  1. Were reliability measures provided?

 

  • Interobserver for analyzers? Yes. Overall inter-rater reliability for imitated/production tasks was 95%. Differences between raters were resolved by consensus.

 

  •  Intraobserver for analyzers? No

 

  • Treatment/Procedural fidelity for investigators? No

 

 

  1. Description of design:
  • The investigators administered 3 tasks to two groups of Swedish speaking children (SLI and TD groups.)
  • Prior to the administration of the tasks, the SLI Ps had been assessed using the Swedish Test of Language Comprehension, T.R.O.G. (a comprehension test), Lund Test of Phonology and Grammar (expressive), ORIS (oral motor skills), and a test of nonverbal IQ.
  • The 3 tasks were

– Imitation of phrases that differed on the placement of stress on the verb particle or on the prepositional phrase (iambic versus trochaic stress.) The examiner provided pictures to support the different sentences.

– Comprehension task in which the participant (P) hears a direction and points to the appropriate picture of a set of 3 (2 contrasting sentences and a foil). The directions were identical sentences that differed only in the placement of stress on the verb particle or on the prepositional phrase (iambic versus trochaic stress.)

– Imitation of phrases with an indefinite article (before the stressed syllable) or a definite form of a noun (after the stressed syllable. This contrasted differed iambic versus trochaic stress. The examiner provided pictures to support the different sentences.

  • The investigators used inferential (nonparametric) and correlational statistics to analyze the data.

 

  1. What were the results of the inferential statistical testing
  • Significant comparisons are p ≤ 0.05.

Dependent Measure #1: Overall number of unstressed syllables omitted across all tasks- Ps with SLI omitted significantly more unstressed syllables and TD Ps.

Dependent Measure #2: Proportion of prestressed syllables omitted in content words versus the proportion of omitted copulas by SLI group—no significant differences

Dependent Measure #3: Comparing the same morpheme in different positions (stressed versus unstressed) and with different functions (verb particle versus preposition) by the SLI group—no significant difference

Dependent Measure #4: Relative strength of performance on imitated versus comprehension tasks concerned with phrasal stress— not analyzed statistically. See descriptive analysis Item #12 in which 3 groups (A, B, C) of Ps with SLI were identified.

Dependent Measure #5: Performance of Groups from measure 4 (see also item #12) on

  • imitation of total unstressed syllables: Group A significantly poorer than other groups.
  • perception of total unstressed syllables: Group B significantly poorer than other groups.
  • imitation of prestressed syllables: Group A significantly poorer than other groups.

Dependent Measure #6: Relationship between linguistic variables and nonverbal IQ among SLI Ps: This measure was analyzed inferentially and correlationally. See item #11 for the correlational analysis.

     – There were no significant differences among the 3 SLI groups (i.e., Groups A, B, and C) with respect to linguistic and nonlinguistic measure.

– What were the statistical test used to determine significance?

  • Mann-Whitney U
  • Kruskal-Wallis
  • Post-hoc analysis by Siegel and Castellan

 

Were evidence-based measures provided: No

– Were confidence intervals provided? No

 

 

  1. What were the results of the correlational statistical testing?

 

– Correlations that od p ≤ 0.05) are considered significant:

 

  • Dependent Measure #6: Relationship between linguistic variables and nonverbal IQ among SLI Ps: This measure was analyzed inferentially and correlationally. See item #10 for the inferential analysis.

     – Overall SLI (i.e., combined Groups A, B, and C) as well as Groups A and B individually—no significant correlation between perception and imitation of stress patterns

     – For Group C there was a significant correlation between perception and imitation of stress patterns (r = 0.85.)

correlationally. See item #10 for the inferential analysis.

     – Overall SLI (i.e., combined Groups A, B, and C), there were no significant correlations for the number of unstressed free morphemes and oral motor skills.

     – Overall SLI (i.e., combined Groups A, B, and C), there was a significant correlation for the number of unstressed free morphemes and receptive language (r = 0. 37.)

 

  1. What were the results of the descriptive analysis?

Dependent Measure #4: Relative strength of performance on imitated versus comprehension tasks concerned with phrasal stress:

  • The investigators identified 3 subgroups within the SLI group.
  • NOTE : throughout the manuscript the investigator used the term “production” instead of “imitation.” I will continue with the term “imitation” because it is more specific. Also, some of the information provided here was found in the results or discussion section.

– GROUP A: Ps who were stronger on the perception/comprehension tasks than on the imitative task. (Criterion: 2 points better on perception/ comprehension tasks than on the imitation task.) These Ps had problems with all aspects of expressive language performance. This also was the smallest group.

– GROUP B: Ps who were stronger on the imitative task than on the perception/comprehension tasks (Criterion: 2 points better on the imitation task than on the perception/ comprehension tasks.) These Ps had more trouble with overall language comprehension than the other 2 groups.

– GROUP C: Ps whose performance on the perception/comprehension tasks and the imitative task were similar. (Criterion: Scores on the perception/ comprehension tasks and the imitative task were the same or within one point of one another.) Although all these Ps had nonverbal IQs of at least 78, as a group their nonverbal IQs were lower than the o

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