REEMERGENCE AND EXTINCTION OF SELF-INJURIOUS ESCAPE BEHAVIOR DURING STIMULUS (INSTRUCTIONAL) FADING

Based on results of a functional analysis indicating that the self-injurious behavior (SIB) of 3 individuals was maintained by negative reinforcement (escape from instructional situations), the effects of stimulus (instructional) fading were evaluated in a multiple baseline design across subjects. The rate of instructions was reduced to zero at the beginning of treatment and was gradually increased (faded in) across sessions as long as SIB remained low. However, if SIB remained high for 10 consecutive sessions, extinction was implemented until SIB decreased, at which point extinction was withdrawn and fading was resumed. Treatment was completed when the rate of instructions was the same as in baseline (two per minute), and SIB remained below 0.5 responses per minute for two consecutive sessions. Results showed that instructional fading (without extinction) virtually eliminated SIB initially, but these effects were not maintained. All 3 subjects required multiple exposures to extinction and over 150 treatment sessions in order to meet the end-of-treatment criteria. Advantages and limitations of fading procedures without an extinction component, as well as extensions of both interventions to other clinical problems, are discussed.     

SCHEDULE EFFECTS OF NONCONTINGENT REINFORCEMENT ON ATTENTION-MAINTAINED DESTRUCTIVE BEHAVIOR IN IDENTICAL QUADRUPLETS

Noncontingent reinforcement (NCR), a response-independent schedule for the delivery of reinforcement, has been found to be effective in reducing behavior when the reinforcer delivered is responsible for behavioral maintenance. In this study, dense and lean schedules of response-independent attention were compared to determine whether it is necessary to begin with a dense schedule before fading to a lean schedule, or whether treatment would be as effective using a lean schedule at the outset. The subjects were 5-year-old identical quadruplets diagnosed with mental retardation and pervasive developmental disorder who displayed destructive behavior that was maintained by social attention. NCR was selected partially because it is not very labor intensive and could be implemented by a single mother simultaneously with all 4 children. Using a combination multielement and multiple baseline design, it was found that (a) a dense schedule of response-independent reinforcement (i.e., fixed-time 10 s) resulted in immediate and dramatic reductions in destructive behavior with no evidence of an extinction burst, and (b) an equivalent reduction in destructive behavior was achieved with a lean schedule of response-independent reinforcement (fixed-time 5 min) only after a systematic fading procedure was implemented. The findings suggest that the effectiveness of NCR may be dependent on the use of a dense schedule initially, and that systematic fading can increase the effectiveness of a lean schedule.     

On the definition of differential reinforcement of alternative behavior

Differential reinforcement of alternative behavior (DRA) has a long history as a behavioral treatment. The term has usually been defined in a manner that suggests one form of behavior (usually some appropriate alternative) is reinforced, while another form of behavior (usually problem behavior) is placed on extinction. In this paper, we will suggest that DRA should not require extinction, either procedurally or by definition. Ideally, problem behavior would be placed on extinction when possible; however, when problem behavior is not or cannot be placed on extinction, the procedure used is still DRA. Thus, we propose the following definition: Providing greater reinforcement, along at least one dimension, contingent on the occurrence of one form or type of behavior, while minimizing reinforcement for another form or type of behavior.     

Early extinction effects following intermittent reinforcement: Little evidence of extinction bursts

The occurrence of extinction bursts—transient increases in response rate in excess of those observed in baseline during the period immediately following discontinuation of reinforcement of a response—was examined. In Experiment 1, key pecking of pigeons was reinforced according to a multiple schedule in which a variable-ratio schedule alternated with an interval schedule in which the reinforcers were yoked to the preceding variable-ratio component. In Experiments 2 and 3, rats were screened such that the lever-press response rates of different rats maintained by variable-interval schedules were either relatively high or relatively low. Following these baseline conditions, in Experiments 1 and 2 responding was extinguished by eliminating the food reinforcer and in Experiment 3 by removing the response–reinforcer dependency. Responses immediately following extinction implementation were examined. Response increases relative to baseline during the first 20 min of a 324.75-min extinction session (Experiment 1) or during the first 30-min extinction session (Experiments 2 and 3) were rare and unsystematic. The results (a) reinforce earlier meta-analyses concluding that extinction bursts may be a less ubiquitous early effect of extinction than has been suggested and (b) invite further experimentation to establish their generality as a function of preceding reinforcement conditions.     

Staff-administered functional analysis and treatment of aggression by an elder with dementia

In the current study, nursing home staff were taught to administer functional analyses to determine the variables maintaining aggression by an elder with dementia. The results indicated that aggression was evoked during bathroom routines and that escape maintained aggression. Staff then reduced aggression to near-zero levels with noncontingent escape. Implications for the assessment and treatment of problem behaviors in nursing home settings are discussed.     

A preliminary examination of the evocative effects of the establishing operation

We attempted to isolate the evocative effects of the establishing operation for positively reinforced problem behavior with 2 participants. The study consisted of three phases. First, a functional analysis identified tangible items (Participant 1) and attention (Participant 2) as maintaining problem behavior. Second, access to tangible items and attention was systematically controlled (continuous access vs. no access) immediately prior to functional analysis sessions in which these consequences were delivered contingent on problem behavior. Results of this phase indicated that problem behavior occurred at higher levels when access to tangible items and attention was restricted. In the third phase, prior access was again controlled, but problem behavior produced no consequences. Results of this final phase indicated that problem behavior occurred at higher levels during extinction sessions when participants did not have prior access to the reinforcers.     

The efficacy of noncontingent escape for decreasing children's disruptive behavior during restorative dental treatment

We evaluated the effectiveness of a dentist-implemented behavioral intervention in which brief escape from dental treatment was provided on a regular basis, independent of the child's behavior. Within a multiple baseline design across subjects, 5 children, ages 4 to 7 years, were provided with temporary escape from dental treatment on a fixed-time schedule. The intervals were signaled by an electronic timer worn by the dentist. Clinically significant reductions were observed in physically disruptive behavior across all 5 children with the introduction of noncontingent escape, and verbally disruptive behavior was markedly reduced in 4 of the 5 children. In addition, the dental staff s use of physical restraint was reduced to near zero across all 5 children. The research extends the literature in both clinical dentistry and in applied behavior analysis by demonstrating that a dentist can easily and effectively implement noncontingent reinforcement to produce clinically significant and socially important changes in children's health behavior.     

Response rate viewed as engagement bouts: resistance to extinction

Rats obtained food pellets by nose poking a lighted key, the illumination of which alternated every 50 s during a session between blinking and steady, signaling either a relatively rich (60 per hour) or relatively lean (15 per hour) rate of reinforcement. During one training condition, all the reinforcers in the presence of the rich-reinforcement signal were response dependent (i.e., a variable-interval schedule); during another condition only 25% were response dependent (i.e., a variable-time schedule operated concurrently with a variable-interval schedule). An extinction session followed each training block. For both kinds of training schedule, and consistent with prior results, response rate was more resistant to extinction in the presence of the rich-reinforcement signal than in the presence of the lean-reinforcement signal. Analysis of interresponse-time distributions from baseline showed that differential resistance to extinction was not related to baseline differences in the rate of initiating response bouts or in the length of bouts. Also, bout-initiation rate (like response rate) was most resistant to extinction in the presence of the rich-reinforcement signal. These results support the proposal of behavioral momentum theory (e.g., Nevin & Grace, 2000) that resistance to extinction in the presence of a discriminative stimulus is determined more by the stimulus-reinforcer (Pavlovian) than by the stimulus-response-reinforcer (operant) contingency.     

Concurrent excitors limit the extinction of conditioned fear in humans

In a human fear conditioning experiment, with on-line expectancy ratings and electrodermal responding as indices of fear, two neutral stimuli (pictures of geometric shapes) were first established as reliable predictors of an electric shock. In the subsequent extinction phase, the two stimuli were repeatedly presented in compound, without the shock. The final test phase consisted of individual stimulus presentations again, which resulted in a strong return of the conditioned responses. This effect was not observed in non-conditioned control stimuli. Hence, behavioral effects of extinction seem highly specific to the stimulus constellation that has gone through the extinction procedure. We argue that pharmacological, behavioral and/or cognitive manipulations that could prevent configural processing of stimulus constellations have direct clinical potential.