The use of an escape contingency and a token economy to increase food acceptance

Escape (termination of a meal) and token-based differential reinforcement of alternative behavior were used as reinforcement to increase acceptance of food. Using a changing criterion design, the number of bites accepted and consumed was gradually increased to 15 bites per meal. These data suggest that, in some cases, escape may be a potent reinforcer for food acceptance.     

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.     

Parental assessment and treatment of food selectivity in natural settings

This study evaluated the effects of a parent-conducted functional analysis and treatment consisting of differential reinforcement of an alternative behavior, escape extinction, and demand fading on food selectivity in a young child with autism. Increases in food acceptance at home and in a restaurant were obtained.     

Leaving patches: effects of economy, deprivation, and session duration

Three pigeons pecked keys for food reinforcers in a laboratory analogue of foraging in patches. Half the patches contained food (were prey patches). In prey patches, pecks to one key occasionally produced a reinforcer, followed by a fixed travel time and then the start of a new patch. Pecks to another key were exit responses, and immediately produced travel time and then a new patch. Travel time was varied from 0.25 to 16 s at each of three session durations: 1, 4, and 23.5 hr. This part of the experiment arranged a closed economy, in that the only source of food was reinforcers obtained in prey patches. In another part, food deprivation was manipulated by varying postsession feeding so as to maintain the subjects' body weights at percentages ranging from 85% to 95% of their ad lib weights, in 1-hr sessions with a travel time of 12 s. This was an open economy. Patch residence time, defined as the time between the start of a patch and an exit response, increased with increasing travel time, and consistently exceeded times predicted by an optimal foraging model, supporting previously published results. However, residence times also increased with increasing session duration and, in longer sessions, consistently exceeded previously reported residence times in comparable open-economy conditions. Residence times were not systematically affected by deprivation levels. In sum, the results show that the long residence times obtained in long closed-economy sessions should probably be attributed to session duration rather than to economy or deprivation. This conclusion is hard to reconcile with previous interpretations of longer-than-optimal residence times but is consistent with, in economic terms, a predicted shift in consumption towards a preferred commodity when income is increased.     

Food choice in rats (Rattus norvegicus): the effect of exposure to a poisoned conspecific

Three experiments were conducted to examine the effects of exposure to a poisoned conspecific on subsequent food aversion in rats. In Experiment 1A, rats that had been aversively conditioned to a cocoa-flavored food were exposed to a poisoned conspecific that had eaten the same food. On the subsequent choice test, the animals increased their aversion to that food. These results were reconfirmed in Experiment 1B, in which a cinnamon-flavored food was used as the stimulus. In Experiment 2, subjects were first exposed to a poisoned conspecific and then conditioned to the food which the conspecific had eaten. On the test, they showed no sign of increased aversion to that food.     

THEORETICAL,PRACTICAL, AND SOCIAL ISSUES IN BEHAVIORAL TREATMENTS OF OBESITY

Although showing superior maintenance, behavioral treatments of obesity typically produce small weight losses at a decelerating rate. Rather than reflecting poor compliance with treatment, these findings are consistent with known compensatory metabolic changes that operate to slow weight loss and promote regain. Other problems associated with dieting include failure of caloric regulation, hyper-responsivity to food palatability, and hunger, which is greatest under conditions of moderate restriction and unpredictability of access to food. The inevitability of treatment failure in many instances must be faced and efforts made to prevent further worsening of the obese patient's self-esteem. Prognosis and treatment planning may be aided by consideration of the historical difficulties of weight loss, the degree of hunger experienced on diets, which may reflect important physiological differences among individuals, and the use of food to optimize arousal level. Full involvement of the patient in setting goals and planning treatment is recommended.     

Assessment of attack and drinking in White King pigeons on response-independent food schedules.

Four White King pigeons in Experiment I were exposed to a fixed-time 90-second food schedule with successive access to water and a conspecific target. Drinking per session was sporadic and minimal, while attack per session occurred during most interfood intervals for all animals. Analysis of the temporal distribution of attack showed that the typical postreinforcement pattern of attack developed over the course of the experiment. In Experiment II, the same animals were exposed to a series of fixed-time schedules ranging from 30 to 360 seconds with successive access to water and target. Time engaged in drinking and the number of interfood intervals with drinking were less than that of attack. Food and no-food baselines, which have been typically used to assess schedules-induced drinking and attack, respectively, were used to evaluate the effect of the schedule on attack and water ingestion. Relative to the no-food baseline, both attack and drinking were enhanced by the schedule in all birds. Relative to the food baseline, drinking was slightly suppressed in three birds and attack was enhanced in all. For all animals, the food baseline resulted in more attack and drinking than the no-food baseline.     

Histological data: Hollard and Davison (1971)

As Mogenson and Cioé (1977) have assumed that our electrodes aimed at the ectostriatum (Hollard and Davison, 1971) were actually located there, we feel that a presentation of the histological data is necessary. Following termination of further experiments (Hollard, 1974) the pigeons, numbered 93, 95, and 119, were sacrificed and perfused with saline followed by 10% formalin. Sections, 50 microns thick, were cut on a freezing microtome. Prints were made by mounting each unstained section of a microscope slide and placing them in a standard photographic enlarger. The electrode tips of Pigeons 93 and 119 were located in the paleostriatal complex. The sections of Pigeon 95 were damaged and precise localization was not possible. Further work in this laboratory has also found that, using the same coordinates, electrode tips tend to fall in the paleostriatum, rather than in the more dorsal ectostriatum at which they are aimed. The paleostriatal placements tended to sustain self-stimulation, whereas others located in the ectostriatum sustained relatively low or unstable rates.     

THE RELATION OF FOOD QUANTITY TO RUMINATION BEHAVIOR

Preliminary work suggested that the quantity of food ingested by retarded individuals who usually ruminated following meals was related to the frequency and duration of ruminating responses. This possible relation was experimentally examined by systematically varying food quantity from regular portions to satiation levels for three retarded individuals who exhibited high levels of ruminating. A clear functional relation of food quantity to ruminating emerged, with satiation procedures producing rapid and large decreases in the relatively high frequencies and durations of ruminating characteristic of baseline food quantity conditions.