Carr

NCR refers to delivering a known reinforcer on a response-independent basis to reduce aberrant behavior.
Commonly reported as a function-based treatment for developmental disabilities.
The review is structured into historical context, research findings, treatment mechanisms, and future research directions.

Functional assessment revolutionized treatments for aberrant behavior, allowing interventions to be based on maintaining variables.
Function-based interventions prioritize reinforcement over punishment, targeting response-reinforcer relationships.
Iwata et al. categorized intervention types:
- Establishing Operations (EOs): Manipulations to weaken reinforcer for aberrant behavior.
- Extinction: Withholding the reinforcer maintaining the aberrant behavior.
- Behavior Replacement: Providing reinforcement contingent on alternative behavior.
NCR is viewed as a manipulation of EOs; it facilitates behavioral reduction through response-independent reinforcement.

Term criticized for misleading connotations:
- Reinforcement is intrinsically contingent.
- No behavior is strengthened through NCR compared to reinforcement procedures.
- Describes multiple distinct treatments, complicating precise understanding.
Despite criticism, NCR remains widely used due to literature prevalence.

Early Studies: Skinner's initial discussion on fixed-time schedules set the stage for NCR studies in the 1960s.
Key research findings:
- Zeiler (1968): Fixed-time schedules yield consistent decreases in behavior compared to variable-time schedules.
- Rescorla & Skucy (1969): Extinction led to more effective response reduction than response-independent food delivery.
- Lachter et al. (1971): Dense fixed-time schedules led to further response reductions than lean schedules.
Consistent findings support NCR's effectiveness as an experimental control relative to extinction.

NCR used as a methodological control to differentiate effects of reinforcement procedures.
Researchers compared NCR with extinction to isolate responses to reinforcement rather than stimulus removal.
Notable studies:
- Hart et al. (1968): Demonstrated NCR effectiveness with social reinforcement.
- Horner (1980): Utilized NCR to assess behavior in conjunction with environmental enrichment.
- Iwata et al. (1994): Reported efficacy of NCR in reducing self-injurious behavior in a majority of cases.

Initial studies by Boe and Thelen did not apply function-based principles.
Modern NCR defined as time-based delivery of stimuli with known reinforcement properties.
Benefits include:
- Addresses response-reinforcer relationships directly.
- Comparable or superior reduction effects compared to other interventions (DRO, DRA).
- Easier implementation of fixed-time schedules compared to other methods.
- Reduced extinction-induced behaviors compared to other treatments.

Parameters Affecting NCR Effectiveness:
- Schedule Form: Most studies utilize fixed-time schedules. Variance in procedural use across implementations (FT, VT, RT, continuous).
- Density and Magnitude: Denser schedules lead to greater initial reductions in behavior (Hagopian et al., 1994).
- Schedule Thinning: Start with dense schedules post-baseline, then gradually thin as behaviors stabilize.
- Extinction Component: Commonly employed with NCR; unclear how essential extinction is to NCR efficacy.
- Adventitious Reinforcement: Risk of inadvertently reinforcing undesired behaviors, especially in high-rate scenarios.
- Combination with Adjunct Procedures: NCR works effectively when combined with differential reinforcement to enhance behavioral alternatives.

Three hypothesized mechanisms:
1. Attenuation of Establishing Operations: Reducing motivation for target behaviors through noncontingent reinforcer delivery.
2. Disruption of Response-Reinforcer Relationship: Interrupting established reinforcer contingencies to facilitate behavior change.
3. Reinforcement of Alternative Responses: By providing NCR during times when aberrant behavior would typically occur, alternative responses may be emitted instead.

Mechanisms of behavior change require further exploration to detail conditions influencing these behaviors.
Investigate adventitious reinforcement, focusing on how behaviors occurring at different frequencies might interact with NCR.
Standardizing methods for schedule thinning remains a research gap, needing consensus across studies.
Incorporate bridge studies to understand NCR's application in varied settings, especially outside clinical environments.
Understanding the transfer of NCR efficacy from controlled studies to natural environments deserves priority. This may establish NCR as a leading treatment for aberrant behavior.