Progress is now being made toward ascertaining the specific effects of rearing conditions on brain and behavior, the properties of the environment that contribute to these effects, and the developmental periods in which brain tissue is most sensitive to environmental modification. (Author/RH)

A Klamath Indian story about why the rabbit is timid. (AH)

This study provided added support for the generalization that the neural processes associated with the startle reflex are engaged by small changes in the auditory environment. They also pointed to a measure of separation between the processes responsible for inhibition and those responsible for latency shift. (Editor/RK)

Two experiments employing 180 rabbits and involving tone conditioned stimuli (CSs) and intraoral water unconditioned stimuli (UCSs) investigated pseudoconditioning of jaw movement. (Editor)

The major question of interest in the present investigation was whether or not a UCS is more effectively represented in STM when its occurrence is relatively surprising as opposed to expected. (Author)

The following series of experiments explores the question of whether the modality of the CS and the index used for conditioned drive are, in fact, important in demonstrating the conditioning of hunger, using natural deprivation as the UCS. (Author)

Two experiments demonstrated that Pavlovian counterconditioning alters not only the responses elicited by an aversive stimulus but also the capacity of that stimulus to act as a reinforcer in a fear-conditioning paradigm. (Author/RK)

This paper reports an observational study of the effects of handling on the social behavior of squirrel monkeys who received a protein deficient diet. After birth, experimental animals received a low-protein diet for a 6-week period. A subgroup of these animals were handled between 3 and 12 weeks of age. All of the animals interacted (in four…

The psychological effects of exercise training are difficult to study in humans, but analogous emotionality changes in animals can be studied using simple measurements employed in emergence and open-field tests. The basis of these tests is that animals that are more emotional are more fearful when placed in a novel situation and will exhibit less…

This paper attempts a unified explanation of such apparently non-utilitarian behaviors as curiosity, manipulation, and exploration as manifestations of "playful behaviors" on the one hand and stereotyped responses on the other. Sensorhesis names the new theory offered to explain the existence and nature of playful behavior. Play and stereotyped…

A comparative approach to the study of communication can be seen as extremely valuable for a thorough understanding of human communication. In its broadest sense, communication is a biological phenomenon, defined as the interchange of information between an organism and its environment. Communication systems of living organisms differ…

Even though many investigators have observed increased intakes of edibles as a function of prior exposure, little systematic research has been done on the effect. The present study was designed to investigate the phenomenon in domesticated rats with a concentrated solution of sodium saccharin used as the ingested substance. (Author)

Computer models of asymptotic reversal learning in pigeons were evaluated on the basis of the results of five experiments which defined the asymptotic pattern of within-sessions and between-sessions reversal (Experiment 1) and which provided data on the effects of intertrial interval (Experiment 2), amount of training preceding reversal…