Abstract
The first purpose of this study is to show that an infant diagnosed as autism acquires some words through the application of operant conditioning procedures. The second is to indicate that words of praise and recognition or physical contact stimuli function as secondary reinforcers. The third is to examine whether he verbalizes words coincident with each task in the free operant situation. The case was a six years and four months old boy who didn't show any interpersonal behaviors, any plays with toy, but a few verbalization. The results were as follows: I) He learned to verbalize the behavior when he wished to be hugged. II) The words of praise and recognition didn't turn to be secondary reinforcers, but physical contact stimuli such as body hug and head stroke showed the reinforcers. III) He didn't verbalize words coincident with each task, but showed more frequent words in the motor task than in the stationary task. The reinforcer will be discussed in the operant conditioning procedure of autistic children hencefoward.
