One of our research programs at Clover Bottom Developmental Center, a state facility for the mentally retarded, seeks ways to measure intellect in quadraplegic, non-verbal children. Their severe motor impairments prevent valid estimates of intellect–they can’t reliably make gross motor or verbal responses. Children so afflicted might be thought mentally retarded because we cannot measure the childs potential.
We are evaluating a procedure to find a reliable motor function that such a child can control; reinforce the exercise of that function, and teach the child to use that motor function to communicate.
Briefly the research program sequence seeks to:
- Identify possible voluntary motor functions that could be used to operate a switch.
- Design and construct a suitable switch and appliances matched to the child’s existing voluntary motor functions.
- Establish an operant-conditioned response using selected stimuli to reinforce switch activation.
- Test conditioned responses with various discriminative stimuli.
- Use a demonstrated, reliable response in a program combining an inexpensive microcomputer and human interaction to train the child in language expression.
Steps 3 and 4 employ the ZX/TS to collect real-time data and, at the end of each session, to analyze the data. Step 5 uses the computer for computer-assisted instruction in communication skills.
Information collected and stored by the ZX/TS includes: child’s name, date, time of day, session length, number of switch operations, duration of each closure and percent of time the switch was activated.
We selected the ZX/TS because it’s low-cost, easy to alter, low-powered (permitting economical and portable battery operation), expandible, furnished with a complete BASIC, & uses a membrane keyboard.
Responses by the child simulate key presses. We simply wired a jack to the keyboard circuit to connect the external switch.