The Neurobehavioral Unit (NBU) at the Kennedy Krieger Institute is a 16-bed inpatient unit devoted to the assessment and treatment of individuals with severe destructive behavior. The primary goals of the program are to: (a) serve as a model for the evaluation and treatment of severe destructive behavior displayed by persons with developmental disabilities; (b) foster the development of new therapeutic procedures through systematic research on the nature and management of destructive behaviors and (c) promote the effective application of currently available treatments through training and consultation.
Individuals (usually between the ages of 2-21) admitted to the NBU engage in a variety of destructive behaviors such as self injurious behavior (SIB), aggression, property destruction, pica, noncompliance and tantrums. Criteria for admission are that behavior is of such a severity and/or intensity that the individual is a danger to him or herself and is at risk for long-term residential placement. Approximately 70-80 percent of clients are diagnosed with severe to profound intellectual disabilities, and approximately 40-50 percent are diagnosed with autism or pervasive developmental disorder. Admission length is usually three to six months.
Individuals admitted to the unit receive psychiatric, educational, developmental, social and behavioral assessments and interventions. Behavioral interventions are developed based on the results of systematic operant analyses, including functional behavioral assessment, analysis of parent-child interactions, competing stimulus assessments and reinforcer assessments. The interventions are designed based on assessment findings to decrease problem behavior and replace it with alternative, appropriate responses. Treatment effectiveness is systematically evaluated using reliable direct-observation measures and single-case experimental designs.
A critical component of the program is to train caregivers (e.g., parents, staff and/or teachers) to implement prescribed behavioral treatments. Pre-admission home and school visits are sometimes conducted to assess both child and caregiver behavior. These assessments continue while the child is an inpatient. Once an effective treatment has been developed, caregivers are trained to implement the intervention at mastery level (90 percent accuracy). Caregivers practice implementation of the treatment in a variety of naturalistic settings under the supervision of a behavior therapist to promote maintenance of treatment gains. Intensive outpatient services are initiated at the time of discharge. Initially, the therapist accompanies the client and family to the home for up to one week to help ensure a smooth transition from the hospital to the client's home. Thereafter, the intensity of services are faded over a two-year period.
Through the collection of systematic program evaluation data, we have found that destructive behavior is decreased by 80 percent or more in at least 80 percent of clients admitted to the inpatient service. Treatments developed on the unit are successfully generalized to the home and school settings for almost all clients. Follow-up data indicate that 60 percents of clients maintain the low rates of destructive behavior achieved during inpatient treatment, and only a small percentage (less than 5 percent) regress to a point where re-admission is required.
Interns who are accepted to the NBU rotation participate in an intensive six-month experience. Following a training and orientation period, each intern is assigned as a primary therapist for one client. The primary therapist is responsible for conducting and developing all of the behavioral assessment and treatment procedures for the client, training unit staff and caregivers to implement protocols and interacting with the interdisciplinary team. The primary therapist works with two back-up therapists who assist in these activities. A licensed psychologist, who will work with the intern for the duration of the case, provides supervision on a daily basis. The structure of supervision may vary depending on the needs of the case and the intern and may include didactic instruction, in vivo or case-centered planning. Additional training opportunities on this rotation include frequent peer review of cases, interdisciplinary rounds and invited speakers.
The NBU has a long history of producing data-based research in a number of areas critical to the assessment of behavior disorders. For example, functional assessment has become a cornerstone in the treatment of severe behavior disorders and many of the initial functional assessment studies originated on the NBU. Today, we continue to systematically explore refinements of the methods of assessing the functions of children's problem behavior. Studies that are currently planned or underway involve ways to modify assessment methods for individuals with low rate, but high intensity destructive behavior; delineating complex functional relationships between aberrant behavior and child mands or requests (e.g., where the function of one response -- destructive behavior -- is to increase the probability of reinforcement of another response -- child mands); identifying functional response classes and manipulating motivative variables and other stimulus parameters to produce clearer functional analysis results.
The NBU has long been a pioneer in research on predicting and enhancing the effectiveness of reinforcers, and on identifying other properties of reinforcers including the extent to which they compete with or complement other reinforcers. Recently, research in this area has been focused on examining the relative efficacy of different modalities of stimulus presentation in the assessment of preference for different classes of stimuli (e.g., leisure items, social interactions, etc.). Other research is directed at identifying variables that may establish (increase) or abolish (decrease) the effectiveness of reinforcing stimuli. Specific current examples include studies that examine changes in the effectiveness of reinforcing stimuli as a function of changes in the requirements for reinforcement, as well as studies to examine the accuracy of child self-reports regarding preferred stimuli and methods to enhance the value of initially neutral stimuli.
In the course of working with patients exhibiting severe problem behavior that historically has been highly resistant to treatment, behavioral psychology faculty on the NBU must continually work to advance and refine existing treatment approaches. Current research is aimed at enhancing commonly used interventions such as functional communication training (FCT) by examining the effects of using Picture Exchange Communication Training to facilitate spontaneous manding and as the communicative response; comparing selection-based versus topography-based communication systems and the development of a diagnostic battery for determining which sort of communication systems (e.g., picture exchange, communication boards, manual signing, etc.) are best suited for use in reducing destructive behavior in children with limited verbal skills and using stimuli that ostensibly compete with the reinforcers maintaining problem behavior to facilitate schedule thinning. More recently, faculty research interests on the NBU have involved teaching individuals with profound social skills deficits (e.g., individuals diagnosed with autistic disorder) to recognize and respond to naturally occurring cues in their environment when requesting social reinforcers (e.g., attention) and the use of signaling procedures to enhance multi-component treatment interventions. In addition to enhancing interventions for problem behavior such as self-injury and aggression, faculty on the NBU have applied ABA principles and methodology toward the assessment and treatment of other problems including anxiety, noncompliance with medical procedures, food refusal and selectivity, as well as medically-based conditions that precipitate problem behavior.
Behavior disorders often involve a complex interaction between operant and biological variables. In conjunction with the medical faculty on the NBU, another major line of research is designed to further our understanding of how biological and operant mechanisms interact in the etiology and maintenance of severe behavior problems. A number of NBU investigations are focused on the evaluation of pharmacological interventions. Notable studies in this area include the development of a data-based protocol to assess the effectiveness of stimulant medication for children with developmental disabilities and attention deficit disorder, as well as the effects of propranolol on burst responding.
In addition to these clinical research endeavors, basic human operant and neuroimaging research projects are also underway. One line of research involves examining whether children with autism display excessive behavioral persistence, decreased sensitivity to ongoing contingencies and decreased behavioral variation. Neuroimaging research currently in progress is aimed at applying operant paradigms to examine neural activation corresponding to basic behavioral processes, including reinforcement, stimulus control and stimulus equivalence learning; neural substrates of basic behavioral processes associated with anxiety; perception of social stimuli in children with autism; as well as neuroplasticity in individuals who are deaf.
Pediatric Feeding Disorders Program:
The Pediatric Feeding Disorders Program has been developing a strong data-based research program in a number of areas, including the functional analysis of mealtime inappropriate behavior, behavioral assessment of food selectivity by type or texture, behavioral assessment of mealtime emesis, antecedent manipulations to reduce mealtime inappropriate behavior and examination of the interaction between biological and operant mechanisms that maintain food refusal. Behavioral research in pediatric feeding disorders is a relatively unexplored territory and, therefore, wide open for research opportunities.