Using a lag schedule to increase variability of verbal responding in an individual with autism.

Research has shown that reinforcing novel behaviors can increase the number of different ways that an individual behaves (Goetz & Baer, 1973; Pryor, Haag, & O'Reilly, 1969). However, it was not until more recently that researchers began to consider variability to be a reinforceable operant in and of itself (Neuringer, 2002). More specifically, Neuringer suggested that variability can be taught using a Lag x schedule of reinforcement, in which x refers to the number of previous responses from which the current response must differ in order for reinforcement to occur (Page & Neuringer, 1985). The purpose of the present study was to extend one of the first studies of a Lag x schedule on verbal responses with human subjects (Lee, McComas, & Jawor, 2002), by increasing the lag criteria while attempting to address some of methodological limitations of the study. The participant was a 7-year-old male with autism. A changing criterion design was used and results showed that 3 novel responses were acquired and varied according to the lag schedule of reinforcement.