Researchers at the University of Birmingham in England sifted through more than 200 published papers and more than 60 intervention studies to evaluate strategies for encouraging nonverbal autistic children to speak.
They found that picture-based communication is an effective method of getting nonverbal children to interact and ultimately speak. In this type of intervention, children might exchange pictures with others in order to request things, or to make comments.
The picture method was better at encouraging speech in children who possessed at least minimal verbal skills, but even nonverbal children could use the system to communicate, study researcher Joe McCleery, a psychologist at the university, told LiveScience.
Another effective intervention, known as pivotal response treatment, involved giving children opportunities to request items and reinforcing their attempts. For example, a child who asked for a ball by saying "Ba," would be rewarded. As with the picture-based system, this method was more effective at getting children to speak if they already spoke a little, McCleery said.
By contrast, the study found little evidence that children improved their communication skills by using sign language, which has been used extensively with nonverbal children with autism. This could be due to the difficulties autistic children have in copying motor behaviors, the researchers said.