Control of responding by a conditioned reinforcer in the presence of free food

Abstract

It has been reported that animals will "work" in preference to "freeloading." However, the variables responsible for this phenomenon are not well understood. Two pigeons were trained to keypeck for food on a fixed-ratio 300 schedule. Next, the food hopper was propped up to permit continuous access to food, and the presence or absence of the hopper light was manipulated. When the hopper light was presented contingent upon the fixed-ratio schedule, keypecking occurred; when it was not presented, keypecking ceased. Thus, responding in the presence of free food was shown to be a function of the conditioned reinforcing properties of the hopper light.

Stimulus Change as a Factor in Response Maintenance With Free Food Available

“…When identical stimulus change was presented contemporaneous with free food and responses produced food with no concomitant stimulus change, responding decreased to nearly zero. Alferink, Crossman, and Cheney (1973) obtained similar data with pigeons. They pointed out that stimuli associated with food presentation acquire reinforcing properties themselves, i.e., they become conditioned reinforcers.…”

Responding in the presence of free food: Differential exposure to the reinforcement source

“…For example, some studies have recorded the amount of reinforcement (or number of food pellets) obtained from both sources and have calculated the percentage of pellets earned (Hothersall, Huey, & Thatcher, 1973;Osborne & Shelby, 1975;Tarte & Snyder, 1973). Others have recorded only the number of responses (Alferink, Crossman, & Cheney, 1973), while yet others have measured just the absolute amount of free food consumed without recording response frequency (Taylor, 1975). Still others have measured the time required to stop eating free food and perform the response (Jensen, Leung, & Hess, 1970) or the time to stop responding and eat free food (Koffer & Coulson, 1971).…”

Discriminación de contingencias en condiciones de contrafreeloading

“…desde los primeros reportes publicados (Jensen, 1963;neuringer, 1970), el interés se centró en tratar de explicar la cantidad de respuestas ejecutadas sobre un operando que proporcionaba pequeñas porciones de un reforzador que se encontraba presente en una fuente sin restricción para ser tomado. la mayoría de los siguientes estudios (alferink, crossman y cheney, 1973;Bilbrey, Patterson y Winokur, 1973;davidson, 1971;enkema, slavin, spaeth y neuringer, 1972;feild, Kasper y Mitchell, 1984;Jensen, 1963;neu-ringer, 1970;osborne y shelby, 1975;singh y Query, 1971;taylor, 1972) utilizaron como procedimiento básico para observar el fenómeno, una primera fase de entrenamiento para responder a un operando y con ello obtener comida por ejemplo. de manera posterior, mantener esa respuesta mediante algún programa de reforzamiento, y finalmente introducir una fuente libre del mismo alimento durante una o varias sesiones de prueba.…”