Showing papers in "Quarterly Journal of Experimental Psychology Section B-comparative and Physiological Psychology in 1981"

Chlordiazepoxide and resistance to punishment.

Abstract: Rats were given intermittent electric foot-shock during food-rewarded alley training. In the test phase, food and shock were given on every trial. These animals persisted in running down the alley in the test phase compared to those without prior shock experience. The effects of chlordiazepoxide (CDP) on this learned resistance to punishment were examined using a long and short interval between trials. It was found that CDP abolished the effect at a long inter-trial interval, but left it unaltered if the interval was short. The results match those found previously with an analogous effect using non-reward. It is suggested that the effects of punishment and non-reward may be mediated by a common process, and that the benzodiazepines may act on this process. This paper is dedicated to Neal E. Miller.

Appetitive Pavlovian-Instrumental Interactions: Effects of Inter-Stimulus Interval and Baseline Reinforcement Conditions:

Abstract: Experiment I manipulated two variables which appear to influence whether a signal for food enhances or suppresses food-rewarded instrumental performance: interstimulus interval (ISI) during classic...

The potentiation effect during serial conditioning.

Abstract: The development of suppression in rats to a target conditioned stimulus (CS) was compared in trace and serial conditioning procedures. The interval between the end of the target CS and the shock unconditioned stimulus (US) was filled by a second CS in the serial, but not the trace, procedure. In five experiments the serial procedure produced superior conditioning. This potentiation effect, however, depended critically upon the level of conditioning to the stimulus interpolated between the target CS and the US. When conditioning to the interpolated CS was either reduced by giving independent nonreinforced trials with this CS alone or enhanced by independent reinforced trials, the potentiation effect was abolished. In addition, the insertion of a trace interval between the target and interpolated CSs reduced the effect. However, the magnitude of conditioning to the target CS was unaffected by post-conditioning changes in the conditioned strength of the interpolated CS. These findings are discussed in terms ...

Visual discrimination learning in rats with lesions of superior colliculus: door-push and approach errors in modified jumping stand.

Abstract: It has been suggested that, for some species, lesions of the superior colliculus affect visual discrimination learning, but only in certain conditions: (a) when problems are first learnt only after operation, or (b) when discriminanda require detailed scanning, or (c) when “approach” responses to the discriminanda are measured, rather than the response of actually touching them. These suggestions were examined in rats learning visual discriminations in a modified jumping-stand apparatus, after sustaining large lesions of the superior colliculus (and in some cases also of the pretectum). The lesions produced open-field hyperactivity and reduced exploration, indicating effective tectal damage, but the rats learnt a series of difficult discriminations in a door-push task as fast as normal rats, and they did not make more approach errors. Their main abnormality in the discrimination apparatus was that they looked less often between the stimulus doors before stepping across to one of them from the central plat...

Are schedule-induced drinking and displacement activities causally related?

Abstract: The acquisition of schedule-induced drinking was studied in hungry rats given food according to an intermittent (fixed-time 45-s) schedule, in three separate experiments. Rate of acquisition of induced drinking was not affected by making the rats thirsty as well as hungry (Experiment I), nor by offering them a palatable saline solution instead of water (Experiment II). Thirst and palatability did affect the asymptotic level of induced drinking. Increasing the level of food deprivation (Experiment III) increased both the rate of acquisition of induced drinking and its asymptotic level. Thus, rate of acquisition of induced drinking was found to depend more on causal factors relevant to feeding than on causal factors relevant to drinking, while asymptotic level of drinking was affected by both types of causal factor. This suggests that the occurrence of induced drinking does not depend primarily on a disinhibition mechanism of the type thought to underlie displacement activities, and hence does not support t...

Are rats short-sighted? Effects of stimulus distance and size on visual detection.

Abstract: Behavioural evidence concerning short-sightedness in rats is apparently conflicting: in some experiments rats have performed poorly with visual stimuli further than about 60 cm distant, while in ot