Augmentative and alternative communication: treatment principles and strategies

Strategies to develop putative biomarkers to characterize the female phenotype with autism spectrum disorders

Current observational inventories used to diagnose autism spectrum disorders (ASD) apply similar criteria to females and males alike, despite developmental differences between the sexes. Recent work investigating the chronology of diagnosis in ASD has raised the concern that females run the risk of receiving a delayed diagnosis, potentially missing a window of opportunity for early intervention. Here, we retake this issue in the context of the objective measurements of natural behaviors that involve decision-making processes. Within this context, we quantified movement variability in typically developing (TD) individuals and those diagnosed with ASD across different ages. We extracted the latencies of the decision movements and velocity-dependent parameters as the hand movements unfolded for two movement segments within the reach: movements intended toward the target and withdrawing movements that spontaneously, without instruction, occurred incidentally. The stochastic signatures of the movement decision latencies and the percent of time to maximum speed differed between males and females with ASD. This feature was also observed in the empirically estimated probability distributions of the maximum speed values, independent of limb size. Females with ASD showed different dispersion than males with ASD. The distinctions found for females with ASD were better appreciated compared with those of TD females. In light of these results, behavioral assessment of autistic traits in females should be performed relative to TD females to increase the chance of detection.

The impact of augmentative and alternative communication intervention on the speech production of individuals with developmental disabilities: a research review

PURPOSE

This article presents the results of a meta-analysis to determine the effect of augmentative and alternative communication (AAC) on the speech production of individuals with developmental disabilities.

METHOD

A comprehensive search of the literature published between 1975 and 2003, which included data on speech production before, during, and after AAC intervention, was conducted using a combination of electronic and hand searches.

RESULTS

The review identified 23 studies, involving 67 individuals. Seventeen of these studies did not establish experimental control, thereby limiting the certainty of evidence about speech outcomes. The remaining 6 studies, involving 27 cases, had sufficient methodological rigor for the "best evidence analysis" (cf. >R. E. Slavin, 1986). Most of the participants (aged 2-60 years) had mental retardation or autism; the AAC interventions involved instruction in manual signs or nonelectronic aided systems. None of the 27 cases demonstrated decreases in speech production as a result of AAC intervention, 11% showed no change, and the majority (89%) demonstrated gains in speech. For the most part, the gains observed were modest, but these data may underestimate the effect of AAC intervention on speech production because there were ceiling effects.

CONCLUSIONS

Future research is needed to better delineate the relationship between AAC intervention and speech production across a wider range of participants and AAC interventions.

Speech and language therapy to improve the communication skills of children with cerebral palsy

BACKGROUND

The production of speech, language and gesture for communication is often affected by cerebral palsy. Communication difficulties associated with cerebral palsy can be multifactorial, arising from motor, intellectual and / or sensory impairments, and children with this diagnosis can experience mild to severe difficulties in expressing themselves. They are often referred to speech and language therapy (SLT) services, to maximise their communication skills and help them to take an independent a role as possible in interaction. This can include introducing augmentative and alternative communication (AAC) systems, such as symbol charts or speech synthesizers, as well treating children's natural forms of communication. Various strategies have been used to treat the communication disorders associated with cerebral palsy but evidence of their effectiveness is limited.

OBJECTIVES

To determine the effectiveness of SLT that focuses on the child or their familiar communication partners, as measured by change in interaction patterns. To determine if individual types of SLT intervention are more effective than others in changing interaction patterns.

SEARCH STRATEGY

Searches were conducted of MEDLINE, CINAHL, EMBASE, PSYCH INFO, LLBA, ERIC, WEB of SCIENCE, NRR, BEI, SIGLE up to December 2002. References from identified studies were examined and relevant journals and conference reports were hand-searched.

SELECTION CRITERIA

Any experimental study containing an element of control was included in this review. This includes non-randomised group studies and single case experimental designs in which two interventions were compared or two communication processes were examined.

DATA COLLECTION AND ANALYSIS

L Pennington searched for and selected studies for inclusion. J Goldbart and J Marshall independently assessed separate random samples each comprising 25% of all identified studies. Two reviewers independently abstracted data from each selected study. Disagreements were settled by discussion between the three reviewers.

MAIN RESULTS

Eleven studies were included in the review. Seven studies evaluated treatment given directly to children, four investigated the effects of training for communication partners. Subjects in the studies varied widely in age, type and severity of cerebral palsy, cognitive and linguistic skills. Studies focusing directly on children suggest that this model of therapy delivery has been associated with increases in treated communication skills by individual children. However, methodological flaws prevent firm conclusions being made about the effectiveness of therapy. In addition, maintenance of these skills was not investigated thoroughly. The studies targeting communication partners describe small exploratory group projects which contain insufficient detail to allow replication, have very low power and cannot provide evidence of effectiveness of this type of treatment.

REVIEWERS' CONCLUSIONS

Firm evidence of the positive effects of SLT for children with cerebral palsy has not been demonstrated by this review. However, positive trends in communication change were shown. No change in practice is recommended from this review. Further research is needed to describe this client group, and its possible clinical subgroups, and the methods of treatment currently used in SLT. Research is also needed to investigate the effectiveness of new and established interventions and their acceptability to families. Rigour in research practice needs to be extended to enable firm associations between therapy and communication change to be made.