RESPONDING MAINTAINED BY THE OPPORTUNITY TO ATTACK DURING AN INTERVAL FOOD REINFORCEMENT SCHEDULE¹

Abstract

Pigeons responded in a two-key situation. Responses on the right key (food key) were reinforced with food presentation on a response-initiated fixed-interval schedule, (i.e., first response after a fixed period of time was reinforced); responses on the left key (target key) were reinforced on a fixed-ratio schedule (i.e., every nth response was reinforced) with the presentation of a target bird that could be attacked. When the interval value of the food reinforcement schedule was varied from 1 min to 5 min, both the rate of attack responding on the target bird and the rate of responding on the target key were a function of the interval value. Responding on the target key was not maintained by the stimulus change associated with target availability, and was successively extinguished and reconditioned by removing and returning the target bird to the restraining box. When food was delivered independently of behavior, responding on the target key either remained unchanged or decreased, but was not eliminated. Responding on the target key was not maintained in the absence of an intermittent schedule of food presentation.

Induction by Reinforcer Schedules

“…Rats showed more attack under the FR condition, suggesting that the response contingency was important and that attack was not simply a result of the stimulation. Other studies of schedule-induced attack (Cherek et al, 1973;Flory & Everist, 1977) have shown similar although less clear-cut effects of FR and FI contingencies. Perhaps other reinforcer-schedule contingencies (e.g., differential reinforcement of low rates) will be found to provide more clear-cut results.…”

“…For this reason alone, the home-cage baseline is not a useful tool for assessing the contribution of reinforcer intermittency to schedule induction. Furthermore, the procedural differences (e.g., deprivation, session length) between a home-cage baseline and a corresponding experimental schedule condition could, under some circumstances, complicate the interpretation of results (Roper, 1981 (e.g., Falk, 1969;Flory, 1971), attack in pigeons (e.g., Cherek, Thompson, & Heistad, 1973), and distress calling in ducklings (e.g., Starr, 1978). In addition, responding is higher in the schedule than in the no-schedule condition.…”

“…With a decrease in interreinforcer interval beyond 30 to 120 s (depending on the condition), the levels of drinking (e.g., Falk, 1969;Flory, 1971) and attack (e.g., Cherek et al, 1973) decrease rather than remaining the same or increasing as they do at longer interreinforcer intervals. This decrease is accompanied by a decreased opportunity to engage in those activities.…”

Induced Attack During Fixed‐ratio and Matched‐time Schedules of Food Presentation

“…Studies that have reported lower levels of induced behavior during response-independent schedules in either all or in some subjects have examined schedule-induced attack (Cherek et al, 1973;Flory & Everist, 1977;Huston & DeSisto, 1971). In one study taxi- dermically prepared targets were employed rather than live target pigeons (Flory & Everist).…”

“…These studies have reported decreases (Cherek, Thompson, & Heistad, 1973;Flory & Everist, 1977;Huston & DeSisto, 1971), increases (Burks, 1970;Falk, 1961b;Flory & Everist, 1977;Schaeffer, Diehl, & Salzberg, 1966), or no difference (Azrin et al, 1966;Cherek et al, 1973;Flory & Everist, 1977) in induced responding during response-independent schedules than during comparable response-dependent schedules. The present study examined levels of induced attack during FR schedules, in which food presentation depended upon the completion of a fixed number of key pecks, with those levels generated during response-independent schedules matched for reinforcement frequency, in which the response key was covered and food was presented independent of responding.…”