Daily administration of cocaine often results in the development of tolerance to its effects on responding maintained by fixed-ratio schedules. Such effects have been observed to be greater when the ratio value is small, whereas less or no tolerance has been observed at large ratio values. Similar schedule-parameter-dependent tolerance, however,…

The article discusses two important influences of B. F. Skinner, and later workers in the behavior-analytic tradition, on the study of animal timing. The first influence is methodological, and is traced from the invention of schedules imposing temporal constraints or periodicities on animals in "The Behavior of Organisms," through the rate…

Philosophers often consider what it is that makes individuals human. For biologists considering the same, the answer is often framed in the context of what are the key differences between humans and other animals. One vestige of human uniqueness still often cited by anthropologists is culture. However, this notion has been challenged in recent…

Pigeons were trained in a matching task with either color (group color-first) or line (group line-first) samples. After asymmetrical training in which each group was initially trained with the same sample on all trials, marked retention asymmetries were obtained. In both groups, accuracy dropped precipitously on trials involving the initially…

In this article we use actual instances of human conduct with animals to reflect on the debates about animal agency in human activities. Where much of psychology, philosophy, and sociology begin with a fundamental scepticism over animal mind as the grounds for its inquiries, we join with a growing body of work that examines the continuities…

In Experiment 1 with rats, a left lever press led to a 5-s delay and then a possible reinforcer. A right lever press led to an adjusting delay and then a certain reinforcer. This delay was adjusted over trials to estimate an indifference point, or a delay at which the two alternatives were chosen about equally often. Indifference points increased…

In the late winter, curriculum at school shifts from studying the environment to birds and mammals. After contacting the local chapter of the Audubon Society and researching a variety of indigenous species to feature, the Atlantic puffin was chosen as an introduction and main theme of study. Students learn how puffins once thrived off the coast of…

In an effort to provide an opportunity for her first graders to explore texture through an engaging subject, the author developed a three-part lesson that features fish in a mixed-media artwork: (1) Exploring Textured Paint; (2) Creating the Fish; and (3) Role Playing. In this lesson, students effectively explore texture through painting, drawing,…

In France, as well as in several other countries, the cell concept is introduced at school by two juxtaposed drawings, a plant cell and an animal cell. After indicating the didactic obstacles associated with this presentation, this paper focuses on the reasons underlying the persistence of these two prototypes, through three complementary…

A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans…

Eye-blink conditioning involves the pairing of a conditioned stimulus (usually a tone) to an unconditioned stimulus (air puff), and it is well established that an intact cerebellum and interpositus nucleus, in particular, are required for this form of classical conditioning. Changes in synaptic number or structure have long been proposed as a…

Three experiments explored renewal in conditioned taste aversion after different amounts of extinction. In Experiment 1, three groups of rats received a single conditioning trial where a saccharin solution was paired with LiCl, followed by 3 extinction trials, and a two-trial test. Groups differed in the context where they received each of the…

Previous work on fish, frogs, and salamanders, showed the ability for estrogen (EE2) and anthropogenic endocrine disruptors to skew sex ratios and cause hermaphrodism. This study addressed the effects of estrogens on growth and development rates of African clawed frog tadpoles ("Xenopus laevis") during their gender determination stages. The…

This study explored changes in student attitudes toward school life following the 1992 Newfoundland groundfishery closure. Using data extracted from a provincial quality of school life (QSL) survey, means associated with students from a sample of fishing communities were compared with provincial means. Although community students had poorer…

Schedule-induced polydipsia in rats was developed by means of a fixed-time 60-s schedule of food presentation. The acute administration of d-amphetamine sulfate (0.1-3.0 mg/kg) produced a dose-dependent decrease in the rate of licking. D-Amphetamine shifted to the left the temporal distribution of adjunctive drinking within interfood intervals.…