A test is described in which three psychotropic drugs were evaluated for their effects on pregnant rats. Behavioral changes are given. (SA)

Experiments related to studying innate responsiveness to auditory stimuli in various infant organisms establish that animals have innate perceptual knowledge. (SA)

Three experiments, employing conditioned suppression in rats, examined the extent to which pretraining on one element of a compound stimulus blocked conditioning to the other element when some feature of the reinforcer was changed on compound trials. (Editor)

The research reported here was directed at evaluating whether or not the effectiveness of a Pavlovian unconditioned stimulus (US) in promoting associative learning is reduced if the US is shortly preceded by another occurrence of the same US. (Author)

Stimulus analyzer theory as proposed by Sutherland and Mackintosh (1971) makes the unique prediction that the first-experienced reinforcement schedule will influence resistance to extinction more than subsequent schedules. Results presently reported of runaway acquisition and extinction indicate the opposite: C-P consistently produce substantially…

Recent data indicate that the form of the conditioned response (CR) may often be substantially influenced by the characteristics of the conditioned stimulus (CS) as well as by those of the unconditioned stimulus (US). Here five experiments examine the influence of CS characteristics on the form of the Pavlovian CR anticipatory to a food US in…

Examines the effects of cage size on stereotyped and normal locomotion and on other abnormal behaviors in singly caged animals, whether observed abnormal behaviors tend to co-occur, and if the development of an abnormal behavior repertoire leads to reduction in the number of normal behavior categories. (Author/RK)

Presents three experiments that explore whether inescapable shock of long duration and moderate intensity (LoShk) produces an avoidance-escape deficit (called an interference effect) by causing animals to learn to respond less actively or by causing them to learn to be "helpless". (Editor)

Several experiments tested the occurrence of the "Kamin effect", i.e., the deficit in performance of an incompletely learned avoidance task, in terms of discrimination (choice) behavior by rats. (Editor/RK)

Repeated, isolated presentations of a stimulus typically reduce the subsequent ability of that cue to become an effective conditioned stimulus. This phenomenon is known as the latent inhibition effect. Four experiments investigate this effect. (Editor/RK)

Authors see the provision of an "aesthetic atmosphere" as one of their greatest challenges. One is an art specialist and the other is a principal. Outlines some of the ways in which they have successfully met that challenge. (Editor/RK)

Compared tendencies of adults and rhesus monkeys to escape adaptively when uncertain. In a visual discrimination task using a threshold paradigm, humans and monkeys escaped trials in which they were uncertain of the stimulus. In a similar task with constant stimuli, some humans escaped adaptively, but one escaped infrequently and non-optimally,…

A dynamic model of how animals learn to regulate their behavior under time-based reinforcement schedules is presented. It assumes serial activation of behavioral states during the inter-reinforcement interval, an associative process linking the states and operant response, and a rule mapping the states onto response rate. (SLD)

A focal-animal sampling technique was applied to measure and quantify visitor behavior at an enclosed hummingbird aviary. The amount of time visitors stayed within the aviary and how they allocated time was measured. Results can be used by exhibit designers to create and modify museum exhibits. (LZ)