Establishing control by spoken words with profoundly mentally retarded individuals.

The team worked with three adults who had profound intellectual disability. None of the adults followed spoken words at the start.

The staff first taught the adults to touch the correct picture when both a picture and a spoken word were present. Then they slowly made the picture smaller and dimmer while the spoken word stayed the same.

The goal was to see if the spoken word alone could control choosing after the picture disappeared.

All three adults learned to pick the correct item by listening only. The fading plan moved control from the visual cue to the auditory cue.

The study showed that even people with very limited language can learn to respond to speech if you fade visual prompts gently.

Kelly et al. (1970) first proved the idea with pigeons. The birds pecked a key when a tone was present only after the light cue was faded out. Fovel et al. (1989) now show the same principle works for humans with severe delays.

WMruzek et al. (2019) extended the idea to preschoolers with autism. They added echoic prompts and got new spoken words to emerge. The 1989 study did not test new words, but both use gradual fading to build auditory control.

Johnson et al. (1994) also worked with adults who had intellectual disability. They added a repeat-out-loud step during delayed-cue training. Their tweak helped when fading alone first failed. Together these papers say: fade slowly, and if needed let the learner say the cue aloud.

If you serve clients who ignore spoken instructions, pair your words with a visual prompt first. Then shrink the prompt bit by bit while keeping the words strong. The fading sequence in this paper gives you a ready-made script. Start today by adding a small visual card to your instruction and plan to make it smaller each day.