How is specific language impairment identified? Dorothy V M Bishop
Specific language impairment (SLI)• Identified in children when language development falls well behind that of other children of the same age• Problems interfere with everyday life and school achievement• Not due to hearing loss, physical abnormality, acquired brain damage, lack of language experience• Not part of a general developmental delay
The first step• Child comes to attention because a parent, caregiver or teacher recognises a problem, such as: • Doesn’t talk much • Language seems immature for age • Struggles to find words • Doesn’t seem to understand what is said • In older children, may fail to understand written language
N.B. Be aware that…• Language problems are not always obvious.• Language difficulties may underlie problem behaviour such as: • Anxiety in social situations • Bad behaviour in class • Inattention • Failure to obey instructions • Problems with peer group • Academic problems (esp. poor reading/writing)Cohen, N. J. (1996). Unsuspected language impairments in psychiatrically disturbedchildren: developmental issues and associated conditions. In J. H. Beitchman, N. J.Cohen, M. M. Konstantareas & R. Tannock (Eds.), Language, Learning, and BehaviorDisorders (pp. 105-127). Cambridge: Cambridge University Press.
Three strands to assessment• Information from parents/caregivers/teachers• Direct observation of the child in a natural setting• Formal assessment using standardized tests
Information from parents and others who know the child• May be seen initially by paediatrician, speech and language therapist, or educational psychologist, who will take a case history• Useful if parent or teacher can give specific examples of how the child communicates and can describe occasions when child’s language problems have been an issue• Need to know what motivates the child to communicate and how communication is achieved – e.g. does the child use gesture/pointing• Can he/she follow simple verbal instructions out of context?• Can he/she understand a story, or talk about something in the past in a coherent sequence?Bishop, D., & Norbury, C. F. (2008). Speech and language disorders. In M. Rutter, D.Bishop, D. Pine, S. Scott, J. Stevenson, E. Taylor & A. Thapar (Eds.), Rutters Child andAdolescent Psychiatry (pp. 782-801). Oxford: Blackwell.
Standardized approaches to parental report• Parental report may be obtained by a standardized interview such as the Vineland Adaptive Behaviour Scales (which also assesses other domains)• The Children’s Communication Checklist-2 is useful for screening for language problems and can be used to pinpoint particular types of difficultySparrow, S. S., Cicchetti, D. V., & Balla, D. A. (2005). Vineland Adaptive BehaviorScales: Second Edition (Vineland II), Survey Interview Form/Caregiver Rating Form.Livonia, MN: Pearson Assessments.Bishop, D. V. M. (2003). The Childrens Communication Checklist, version 2 (CCC-2).London: Pearson.
Direct observation of the child• Clinician may observe how the child communicates with a parent• For those at school, it can be informative to observe the child interacting with other children in the classroom• The focus will be on the language used by the child, the extent to which the child appears to understand what others say, and whether the child uses nonverbal means of communication, such as gesture and facial expression
Standardized assessments• A standardized assessment is one that has been given to a large group of children of different ages, to establish the normal range of performance.• Test scores are often reported as percentiles, which indicate the percentage of people obtaining a score at a given level or below. – A score at the 50th percentile is average for age – half the population would be expected to get a score lower than that – A score at the 10th percentile would mean one in 10 children would get a score this low (or lower) – Common cutoffs for disorder: either 16th percentile or 10th percentile
Test scores and language impairment– Scores are not set in stone: a child’s performance may vary depending on how they feel on the day– In general, language impairment would not be identified on the basis of a single language test– It’s more usual to give a collection of assessments that look at different aspects of language, and then to consider the overall profile– One way of combining information devised by Tomblin and colleagues: EpiSLI (see next slide)
EpiSLI criteria EXPRESSIVE RECEPTIVE Vocabulary Vocabulary Vocabulary composite Grammar Grammar Grammar composite Narrative Narrative Narrative composite Expressive composite Receptive compositeTotal of 6 tests, giving 5 compositesLanguage impairment: 10th percentile or lower on 2+ language compositesTomblin, J. B., Records, N. L., Buckwalter, P., Zhang, X., Smith, E., & OBrien, M. (1997).Prevalence of specific language impairment in kindergarten children. Journal of Speechand Hearing Research, 40(6), 1245-1260.
Limitations of test scores– Test scores have advantage of being reasonably objective; standardized tests have strict instructions on administration and scoring– But some aspects of communication not easy to capture on tests– Also, should we worry about a child who gets low test score if neither teachers or parents are concerned?– In Tomblin et al study, only 29% of children meeting EpiSLI criteria were enrolled in intervention
Combining test scores and parental report – Parental checklist, CCC-2, identifies different subset of children than standardized tests – Children identified by parental checklist do often have academic problems, so seems parental report is capturing important information that may not be picked up by tests – May be best to combine both sources of information: standardized tests and parental reportBishop, D. V. M., & McDonald, D. (2009). Identifying language impairment in children:combining language test scores with parental report. International Journal of Languageand Communication Disorders, 44, 600-615.
Assessing nonverbal abilities– Children with SLI often have additional problems, especially with attentional skills and motor skills– However, they are usually distinguished from children who have a generalised cognitive impairment by the fact that they have normal range nonverbal ability– Assessment of nonverbal ability is done using a standardized test that looks at ability to reason using nonverbal material, e.g. shapes and pictures.
Debate over nonverbal ability – Some formal definitions of specific language impairment, such as the one in the International Classification of Diseases – 10, require that a child has a substantial gap (1 SD or more) between their nonverbal ability and language ability – This has been criticised on several counts: • Very few children meet that criterion • A child’s response to treatment doesn’t depend on whether they have a big or small gap between language and nonverbal ability • Twin studies do not support the idea of a language-nonverbal gap as defining a coherent group with a common genetic basisBishop, D. V. M. (2004). Specific language impairment: diagnostic dilemmas. In L.Verhoeven & H. Van Balkom (Eds.), Classification of Developmental LanguageDisorders (pp. 309-326). Mahwah, NJ.: Erlbaum.
EpiSLI criteria (Tomblin et al)• SLI definition requires normal range nonverbal ability, but does not require large gap with language. Also studied children with Nonspecific LI, with low language/nonverbal scores• Specific language impairment (SLI): – score at/below 10th percentile or lower on two or more language composites – 19th percentile or above on nonverbal IQ• Non-specific language impairment (NLI): – score at/below 10th percentile or lower on two or more language composites – below 19th percentile on nonverbal IQ These two groups vary in severity, and the SLI group has better outcome. But overall, differences are a matter of degree; few qualitative differences
Terminology Speech, language and communication needs SLI =Developmental dysphasia = Specific developmental language disorder = Primary language impairment