Nonvocal language acquisition in adolescents with severe physical disabilities: Bliss symbol versus iconic stimulus formats.
For non-vocal teens with severe disabilities, everyday photos beat abstract Bliss symbols: faster learning, stronger maintenance, and more spontaneous use.
01Research in Context
What this study did
The team worked with non-vocal high-school students who had severe physical and developmental disabilities.
They compared two picture systems: abstract Bliss symbols versus easy-to-guess iconic photos.
An alternating-treatments design let each teen learn the same words in both formats during daily sessions.
What they found
Iconic pictures won by a mile.
Students needed about four times fewer trials to master them, kept the words longer, and used them all day without prompting.
Bliss symbols took more work and faded when staff stopped reminding.
How this fits with other research
Benson-Goldberg (2025) seems to disagree: her group found that sprinkling picture symbols into reading passages actually hurt comprehension in people with IDD.
The key difference is task.
I et al. used pictures alone for expressive requests, while Sofia embedded pictures inside printed text, which may overload the reader.
Mavritsakis (2024) extends the good-news pattern: moving a teen from low-tech letter board to iPad AAC also lifted spontaneous language, showing the 1982 picture advantage holds with modern tech.
Howard et al. (1988) used the same quick-switch design and likewise showed that adding clarity—spoken words with signs—speeds learning, echoing the value of intuitive cues.
Why it matters
Pick the picture that looks like the item.
Skip fancy abstract symbols unless your learner already knows them.
Start with clear photos or line drawings, master a few highly preferred items, then probe in new rooms and with new staff to lock in the skill.
If you later add written words, keep the pictures separate from the text line to avoid the comprehension drop Sofia saw.
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Join Free →Swap any abstract symbols on the teen's device for clear photos of their actual items and run three request trials—note how many prompts you save.
02At a glance
03Original abstract
This study compared training in two language systems for three severely handicapped, nonvocal adolescents: the Bliss symbol system and an iconic picture system. Following baseline, training and review trials were implemented using an alternating treatments design. Daily probes were conducted to assess maintenance, stimulus generalization, and response generalization, and data were collected on spontaneous usage of either language system throughout the school day. Results showed that students required approximately four times as many trials to acquire Bliss symbols as iconic pictures, and that students maintained a higher percentage of iconic pictures. Stimulus generalization occurred in both language systems, while the number of correct responses during responses generalization probes was much greater for the iconic system. Finally, students almost always showed more iconic responses than Bliss responses in daily spontaneous usage. These results suggest that an iconic system might be more readily spontaneous usage. These results suggest than an iconic system might be more readily acquired, maintained, and generalized to daily situations. Implications of these findings for the newly verbal person were discussed.
Journal of applied behavior analysis, 1982 · doi:10.1901/jaba.1982.15-241