Response repetition in pigeons: pharmacological and behavioral specificity

Abstract

Using a reinforcement schedule that arranges random sequences of reinforcements over two response keys, low and high probabilities of repetition of non-reinforced responses were generated in two groups of pigeons (n = 3 per group) by varying the probability of reinforcement for responding on the key to which reinforcement was assigned. Unlike rats, the pigeons did not show a tendency to repeat just-reinforced responses, but showed a strong position bias, that was reduced by additional feeding and extinction, but not by any of the drug treatments. Apomorphine increased response repetition, irrespective of the control probability of repetition; d-amphetamine increased low probabilities of repetition, but decreased high probabilities. Chlordiazepoxide and scopolamine selectively decreased high probabilities of repetition; phencyclidine and pentobarbital selectively increased low probabilities of repetition. Morphine, haloperidol, chlorpromazine, additional feeding, and extinction did not affect repetition of non-reinforced responses. Extinction increased perseveration, whereas drug effects on perseveration were not observed. Drug-induced changes of patterning of responses as exemplified herein by drug-induced alterations of repetitiveness may be relevant to the interpretation of drug effects upon performance brought about by other behavioral processes such as discrimination.

A comparison of the effects of amphetamine, apomorphine and white noise on response switching in the rat

“…Proportional data are generally reported in support of the rate-dependent effects of drugs, although this method of analysis has received criticism (Gonzalez and Byrd 1977) and is clearly less appropriate for choice data when there are a priori limits to behavioural change. Whether the effect is baseline dependent or not, it differs from the previous reports of Robbins (1980) and Koek and Woods (1986) that apomorphine reduces the frequency of switching.…”

“…Evenden, Merck Sharp and Dohme Neuroseience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK it when the baseline was high. Koek and Woods (1986) also found that CDP had a similar effect. However, the direct dopamine agonist apomorphine has been reported as increasing repeat or perseverative responding in both rats and pigeons in a baseline independent manner (Robbins 1981; Koek and Woods 1986).…”

“…Koek and Woods (1986) also found that CDP had a similar effect. However, the direct dopamine agonist apomorphine has been reported as increasing repeat or perseverative responding in both rats and pigeons in a baseline independent manner (Robbins 1981; Koek and Woods 1986). This has led to the suggestion that the increase in switching produced by amphetamine may result from exaggeration of the modulated release of dopamine from the DA terminals (Robbins and Evenden 1984).…”

“…This effect has been shown to be relatively pharmacologically specific, since cis-flupenthixol and chlordiazepoxide (CDP) did not have the same effect (Evenden and Robbins 1983a), but was dependent both upon the dose of drug employed and the baseline frequency of switching (Evenden and Robbins 1983b). The effect has been shown to occur under several different schedules of reinforcement in rats (Laties et al 1981 ;Robbins 1983b, 1985), in pigeons (Laties 1972;Evenden 1986;Koek and Woods 1986) and, using methamphetamine, in primates (Moerschbaecher et al 1979). Evenden (1986) and Koek and Woods (1986) noted that, in the pigeon, at least, increases in switching may be obtained by compounds of other pharmacological classes under certain circumstances.…”

“…The effect has been shown to occur under several different schedules of reinforcement in rats (Laties et al 1981 ;Robbins 1983b, 1985), in pigeons (Laties 1972;Evenden 1986;Koek and Woods 1986) and, using methamphetamine, in primates (Moerschbaecher et al 1979). Evenden (1986) and Koek and Woods (1986) noted that, in the pigeon, at least, increases in switching may be obtained by compounds of other pharmacological classes under certain circumstances. In both studies, scopolamine increased switching when the baseline was low, although reducing Offprint requests to: J.L.…”