USE OF EXTINCTION AND REINFORCEMENT TO INCREASE FOOD CONSUMPTION AND REDUCE EXPULSION

Extinction and reinforcement contingencies were used to treat 2 children with feeding disorders. Positive reinforcement and avoidance extinction effectively increased food acceptance but also increased food expulsion. Reduced expulsion and increased swallowing were achieved by repeated presentation of expelled food, a second extinction component.     

BEHAVIORAL ASSESSMENT AND TREATMENT OF CHRONIC FOOD REFUSAL IN HANDICAPPED CHILDREN

In this study, we examined the eating behavior of four handicapped children, none of whom exhibited self-feeding skills. All children had a history of food refusal and were nutritionally at risk; one child received all nourishment by way of a gastrostomy tube. Baseline data taken during mealtimes indicated that all children accepted very little food, expelled food frequently, and engaged in a number of disruptive behaviors. Treatments consisted of one or more of the following contingent events: social praise, access to preferred foods, brief periods of toy play, and forced feeding. Results of multiple-baseline and reversal designs showed marked behavioral improvement for each child and increases in the amount of food consumed. Further improvements were noted at follow-up, which ranged from 7 to 30 months posttreatment.     

Quantification of rats' behavior during reinforcement periods

What is treated as a single unit of reinforcement often involves what could be called a reinforcement period during which two or more acts of ingestion may occur, and each of these may have associated with it a series of responses, some reflexive, some learned, that lead up to ingestion. Food-tray presentation to a pigeon is an example of such a “reinforcement period.” In order to quantify this behavior, a continuous-reinforcement schedule was used as the reinforcement period and was chained to a fixed-ratio schedule. Both fixed-ratio size and reinforcement-period duration were manipulated. Rats were used as subjects, food as reinforcement, and a lever press as the operant. Major findings included (a) a rapid decline in response rates during the first 15 to 20 seconds of the reinforcement periods, and (b) a strong positive relationship between these response rates and the size of the fixed ratio. Also revealed was a short scallop not normally found in fixed-ratio response patterns, whose length was a function of fixed-ratio size and reinforcement-period duration. It is suggested that rapidly fluctuating excitatory processes can account for many of these findings and that such processes are functionally significant in terms of behavioral compensation.     

Changes in feeding and foraging patterns as an antipredator defensive strategy: a laboratory simulation using aversive stimulation in a closed economy.

The effects of the risk of electric shock on the meal patterns of rats living in an operant chamber were investigated. Rats could obtain food by working on a response lever that provided reinforcement according to chained fixed-ratio continuous reinforcement schedules that allowed the animals control over meal size. Using a two-compartment operant chamber with a safe nesting area and manipulanda area with a grid floor, shock could be correlated with responding on the schedule. Shocks (less than or equal to 1.25 per hour) were scheduled to occur randomly throughout the day, independent of the rat's behavior. Shock caused a reorganization of meal patterns such that the animals took less frequent but larger meals. This pattern reduced the time the animals spent at risk without compromising caloric balance. Similar changes in feeding pattern were obtained in both hooded and albino rats. Exposure to shock in a separate chamber did not produce these behavioral modifications. The magnitude of shock-induced alterations of meal patterns was greater with chained fixed-ratio 90 continuous reinforcement than with chained fixed-ratio 10 continuous reinforcement. Additionally, the rats seemed to be able to reduce food intake but increase caloric efficiency, such that the reduced food intake did not have deleterious effects on maintenance of body weight. These behavioral modifications reduced the number of shocks received from that which would have been expected if meal pattern changes had not occurred. We suggest that this technique may provide a useful laboratory simulation of the impact that the risk of predation has on foraging behavior.     

IMPACT OF PARENTAL BINGE EATING DISORDER: EXPLORING CHILDREN'S EMOTIONAL/BEHAVIORAL PROBLEMS AND THE QUALITY OF PARENT–CHILD FEEDING INTERACTIONS

This study examines psychopathological problems in children of parents with binge eating disorder (BED), particularly the effect of parental diagnosis on their offspring's psychopathology and the mediating power of the quality of parent–infant feeding interactions. Two hundred parents and their offspring were administered a questionnaire for the assessment of their children's psychopathology at 18 (T1) and 36 (T2) months of age. An observational measure to evaluate feeding interactions was administered at T1. Children with both parents with BED showed the highest affective, anxiety, oppositional/defiant, and autism spectrum problems, but no influence of paternal diagnosis was found on the offspring's psychopathology. Maternal BED had an influence on children's affective and autism spectrum problems, and diagnosis of BED in both parents had an effect on infants’ affective problems. Paternal BED had an effect on oppositional/defiant problems through the quality of father–infant interactions, and maternal BED had an effect on the offspring's affective and anxiety problems through the mediation of mother–infant interactions. These results suggest the importance of intervention programs focusing both on parental psychopathology and on mother–child and father–child feeding interactions in families with parents with BED.     

Using food redistribution to reduce packing in children with severe food refusal

Positive- and negative-reinforcement-based procedures typically have targeted acceptance for children with severe food refusal; however, these procedures do not always result in successful swallowing. Once acceptance is achieved, some children expel the food repeatedly or pack (hold or pocket) it in their mouths for extended periods of time. This study evaluated the effects of using food redistribution with a bristled massaging toothbrush to reduce packing and increase consumption in 4 children with severe feeding disorders. Packing was reduced for all children. In addition, latency to clean mouth (the duration of time from acceptance to food no longer being present in the child's mouth in the absence of expulsion) for 2 children decreased when the food-redistribution procedure was used. Results are discussed in terms of the potential operant functions of the food-redistribution procedure.     

The use of the placebo effect in clinical medicine — ethical blunder or ethical imperative?

The current debate in medical ethics on placebos focuses mainly on their use in health research. Whereas this is certainly an important topic the discussion tends to overlook another longstanding but nevertheless highly relevant question, namely if and how the placebo effect should be employed in clinical practice. This paper describes the way the placebo effect is perceived in modern medicine and offers some historical reflections on how these perceptions have developed; discusses elements of a definition of the placebo effect; and suggests some conditions under which making use of the therapeutic potential of the placebo effect can be ethically acceptable, if not warranted. An earlier version of this paper was presented at an international conference, “Placebo: Its Action and Place in Health Research Today,” held in Warsaw, Poland on 12–13 April, 2003. Nikola Biller-Andorno, MD, PhD, is Assistant Professor in the Dept. of Medical Ethics and History of Medicine, University of Goettingen, Germany. Dr. Biller-Andorno also serves as an ethicist for the World Health Organization (WHO). This paper does not necessarily reflect the views of the World Health Organization.     

On the relative contributions of positive reinforcement and escape extinction in the treatment of food refusal

We compared the effects of positive reinforcement alone, escape extinction alone, and positive reinforcement with escape extinction in the treatment of the food and fluid refusal of 4 children who had been diagnosed with a pediatric feeding disorder. Consumption did not increase when positive reinforcement was implemented alone. By contrast, consumption increased for all participants when escape extinction was implemented, independent of the presence or absence of positive reinforcement. However, the addition of positive reinforcement to escape extinction was associated with beneficial effects (e.g., greater decreases in negative vocalizations and inappropriate behavior) for some participants.     

EFFECTS OF CALORIC LEVEL ON RUMINATING

A series of recent studies has shown that a number of dietary variables affect ruminative behavior in institutionalized retarded persons. This experiment extends an earlier study that examined the influence of the caloric level of the diet on the frequency of ruminating. Subjects consumed regular portions of food that varied between phases from normal to high caloric levels. The data show a clear but modest inverse relation between the caloric value of the diet and the rates of postmeal ruminating.     

Teaching behavior analysts in an early intensive behavioral intervention setting to conduct a structured mealtime protocol

Children with autism spectrum disorder often display feeding problems, such as consumption of a limited variety of foods. It is also common for these children to be enrolled in early intensive behavioral intervention (EIBI) services for comprehensive treatment. Combined, these factors make it possible that behavior analysts will have a role in a child's clinical care related to feeding. However, given that the etiology of pediatric feeding disorders is complex and multifactorial, clinicians should ensure they have sufficient training and a setting that is appropriate for assessment and treatment. Therefore, we evaluated the effects of behavioral skills training in an EIBI setting to conduct a structured mealtime protocol. Training resulted in increases in procedural integrity, and we replicated these effects for all participants.