ABSTRACT
Eight pigeons were initially trained to peck a white key for food under a variable-interval 1-min schedule of reinforcement. Then, a shock-avoidance schedule was initiated and food was no longer available in the experimental situation. Under the avoidance schedule, each peck on the key postponed shock for 40 sec. A warning signal, consisting of tone and red houselights, was presented after 30 sec without a response. If no response occurred, a shock was delivered 10 sec after warning-signal onset. Shocks were delivered every 10 sec in the presence of the warning signal until a response was made. The warning signal was terminated only by a response. Key pecking of all eight pigeons came under control of the avoidance schedule and responding continued throughout the 20-day avoidance training period.
Subject(s)
Auditory Perception , Conditioning, Operant , Reinforcement, Psychology , Visual Perception , Acoustic Stimulation , Animals , Appetitive Behavior , Attention , Avoidance Learning , Columbidae , Conditioning, Classical , Electroshock , Feeding Behavior , Male , Models, Psychological , Photic Stimulation , Punishment , RewardABSTRACT
The effects of d-amphetamine on punished responding were studied in two experiments. In Experiment I, pigeons responded under a multiple fixed-ratio 30 response fixed-interval 5-min schedule of food presentation with 60-sec limited holds in both components. Each response was punished with electric shock, the intensity of which was varied systematically. In Experiment II, another group of pigeons responded under a multiple fixed-interval 5-min fixed-interval 5-min schedule of food presentation with 40-sec limited holds. Each response was punished with shock during one component, and every thirtieth response was punished in the other component. d-Amphetamine increased overall rates of punished responding only rarely under any of the punishment conditions; however, response rates within the fixed-interval when rates were low were increased by d-amphetamine when the shock intensity was low (Experiment I), or when responses produced shock intermittently (Experiment II). The data suggest that the effects of d-amphetamine on punished responding depend on the control rate of responding, the punishment intensity, the punishment frequency, and the schedule of food presentation.
Subject(s)
Conditioning, Operant/drug effects , Dextroamphetamine/pharmacology , Punishment , Animals , Columbidae , Dextroamphetamine/administration & dosage , Dose-Response Relationship, Drug , Electroshock , Feeding Behavior , Male , Reinforcement Schedule , SulfatesABSTRACT
Pigeons were trained to depress a lever to avoid electric shock under free-operant avoidance schedules without a warning signal, or with a warning signal that could be terminated only by a response. Most birds in the signalled avoidance procedure terminated more than 50% of the warning signals before shock. In the unsignalled avoidance procedure, several birds formed a temporal discrimination and received relatively few shocks; other birds responded only in post-shock bursts, and received many more shocks.
