Association for Behavior Analysis International

Research on operant behavior often focuses exclusively on response frequency because it is a convenient measure and easier to quantify than are changes in other dimensions such as topography (form) or force. However, force is a fundamental aspect of a response because some amount of force must occur for the response to be detected. In addition, force may be the most relevant defining feature of some responses such as aggression. These studies examined the relation between response rate and response force in two translational contexts. The rate and force of switch presses were measured under conditions of reinforcement and extinction (Study 1) and ratio schedules of reinforcement (Study 2) applied to response rate. Results showed positive correlations between rate and force under some conditions but negative correlations under others. In addition, a higher number of extinction bursts were observed in response force than response frequency.

Although economic relations have been demonstrated using price manipulations for individuals with developmental disabilities, few studies have examined the extent to which similar relations obtain with manipulations involving delay. The current study evaluated the correspondence between demand curves constructed for concurrently available stimuli when work requirements or delay to reinforcement for one stimulus was increased. Four individuals with developmental disabilities participated. Choices between stimuli were assessed under concurrent fixed-ratio (FR) 1 schedules. Then, response requirements were held constant for one stimulus but increased across phases for the other stimulus. In one comparison, both stimuli were similar; in the other, they were dissimilar. The average time between completion of the first response and delivery of reinforcement was assessed for each FR schedule. During the delay manipulation, delay values were yoked to the average amount of time required to complete the corresponding FR schedule. In general, demand for similar stimuli was more elastic than for dissimilar stimuli for both FR and delay manipulations. The results are discussed in terms of their implications for development of effective training or treatment procedures for individuals with developmental disabilities.

Autism is characterized by many deficits, including impairments in reciprocal social interaction skills. The current study investigated differences in the effectiveness of activities as reinforcers when children diagnosed with autism could engage in those activities in isolation or with a parent. Between three and 12 children, aged 8-10, participated. Progressive-ratio (PR) analyses were conducted with three pairs of social and nonsocial activities (six activities total). The pairs of activities included playing videogames alone (nonsocial) and playing videogames with mom (social, N = 12), building alone and building with mom (N = 4), and reading alone and reading with mom (N = 3). Population demand curves were then constructed for each activity based on PR break points, reflecting the proportion of children that completed each schedule requirement to access the activity. Break points and demand curves were compared for social and nonsocial activities in each pair. Break points were higher for social stimuli than nonsocial stimuli in 78.9% of comparisons. Demand curves shifted to the right for social activities relative to nonsocial activities for all three activities. Results suggest that social activities can be effective reinforcers for children with autism, and, in some cases, may be more effective than nonsocial activities.