INDUCED ATTACK DURING MULTIPLE FIXED‐RATIO, VARIABLE‐RATIO SCHEDULES OF REINFORCEMENT¹

Abstract

Two pigeons were exposed to a multiple schedule of reinforcement: in the presence of one discriminative stimulus, key pecks produced grain according to a fixed-ratio schedule; in the presence of a second discriminative stimulus, key pecks produced grain according to a variable-ratio schedule. The key-peck requiremiients in the two components were increased in successive stages from 50 to 125 responses. Live target pigeons were restrained at the rear of the chamber. Attacks against the targets were automatically recorded, and a variety of measures of attack behavior were taken. Attacks, when they occurred, always followed grain presentation. All measures revealed higher levels of attack during the fixed-ratio component at all parameter values. All measures generally increased with increases in fixed-ratio values with both birds, and with increases in variable-ratio values with one bird. With the other bird, only the per cent of reinforcements followed by attack increased with increases in variable-ratio value; all other nmeasures first increased and then decreased. In experiments on schedule-induced aggression, positive reinforcement is usually dependent upon operant responding (e.g., key pecking), and a target is available. Under some schedule parameters, animals will attack either restrained animals of the same species or a variety of inanimate objects. Attack, when it occurs, is primarily a post-reinforcement phenomenon. Schedule-induced aggression has been studied during fixed-ratio schedules

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

“…The divergence among the attack measures underscores the importance of using a variety of measures in analyzing induced behavior, as well as evaluating the appropriateness of each measure of the strength of induced behavior (cf. Allen et al, 1981;Webbe et al, 1974).The present results are similar to those of Huston and DeSisto (1971) comparing levels of interspecific attack during FR and FT schedules of intracranial stimulation (ICS) equated for average reinforcement frequency. The mean number of attacks by rats directed against frogs was greater under FR conditions Table 2 Mean interreinforcement times and standard deviations in s for the last 15 sessions under the initial fixed-ratio phase, the yoked matched-time phase, and the subsequent fixed-ratio phase for P-3478 and P-4817 in Experiment 1.…”

“…Adjunctive or schedule-induced behavior includes drinking or polydipsia in rats (e.g., Falk, 1961a,b), pigeons (Magyar & Malagodi, 1980), and monkeys (Porter & Kenshalo, 1974), aggression in rats (Huston & DeSisto, 1971) and pigeons (e.g., Azrin, Hutchinson, & Hake, 1966;Flory, 1969a;Pitts & Malagodi, 1996;Webbe, DeWeese, & Malagodi, 1974); escape (Azrin, 1961;Brown & Flory, 1972;Thompson, 1964); wheel-running (Levitsky & Collier, 1968); hose-biting (DeWeese, 1977;Hutchinson, Azrin, & Hunt, 1968); and a host of other activities (Kelly & Hake, 1970;Killeen, 1975;Lyon & Turner, 1972;Mendelson & Chillag, 1970;Miller & Gollub, 1974;Muller, Crow, & Cheney, 1979;Staddon & Simmelhag, 1971). These topographically dissimilar behaviors display certain functional commonalities when induced during schedules of reinforcement, including: (a) the temporal locus within the interreinforcement interval (induced behavior typically occurs in the immediate postreinforcement period when operant or terminal behavior is low in probability); (b) the gradual development over time of induced behavior with extended exposure to schedule conditions; and (c) the sensitivity of induced behavior (in terms of amount and probability) to schedule parameters (e.g., Allen, Sicignano, Webbe, & Malagodi, 1981;Burks, 1970;Cherek & Heistad, 1971;Cherek & Pickens, 1970;DeWeese, 1973;Dove, Rashotte, & Katz, 1974;Falk, 1961bFalk, , 1966 Flory, 1969a,b;Knutson & Kleinknecht, 1970;Webbe et al, 1974). These similarities have led …”

“…During the 4-s grain presentations, both the houselights and the keylight were turned off and the raised food hopper was lit with white light. The apparatus for recording attack was similar to that described by Azrin et al (1966) and Webbe et al (1974) and was located at the rear of the chamber, 39 cm from the stimulus panel. The target pigeons were restrained in a clear plexiglass restraint unit that was mounted on a spring-loaded metal plate.…”

“…The shield and the fur bib allowed for consistently high levels of attack without the occurrence of a single injury to the target pigeons (cf. Webbe et al, 1974).White noise was continuously present in the room where the experimental chamber was located. An exhaust fan on the side of the chamber provided ventilation.…”

RELATION BETWEEN LEVEL OF FOOD DEPRIVATION AND RATE OF SCHEDULE‐INDUCED ATTACK1

“…Temporally, the attack is most frequent shortly after food presentation and diminishes in frequency as the interval since food presentation increases (e.g., Dove et al, 1974;Flory, 1969aFlory, , 1969bGentry, 1968;Webbe, DeWeese, and Malagodi, 1974). When multiple schedules have been investigated, rate of attack is higher in the component of the schedule with the lower rate of food presentation Cohen and Looney, 1973;Cole and Litchfield, 1969;Flory, 1969a;Looney and Cohen, 1974).…”