The sunk cost effect is the increased tendency to persist in an endeavor once an investment of money, effort, or time has been made. To date, humans are the only animal in which this effect has been observed unambiguously. We developed a behavior-analytic model of the sunk cost effect to explore the potential for this behavior in pigeons as well…

Four rats responded under a "self-control" procedure designed to obtain delay- discount functions within sessions. Each session consisted of seven blocks, with seven trials within each block. Each block consisted of two initial forced- choice trials followed by five free-choice trials. On choice trials, the rats could press either of two…

To test the hypothesis that social rearing may induce malleability, socially reared and socially isolated mallard duck, Anas platyrhynchos, embryos and hatchlings were exposed to the maternal call of a chicken, Gallus gallus domesticus, until 48 h after hatching. The hatchlings were then tested with the chicken call versus the mallard maternal…

Rhesus monkeys were trained and tested in visual and auditory list-memory tasks with sequences of four travel pictures or four natural/environmental sounds followed by single test items. Acquisitions of the visual list-memory task are presented. Visual recency (last item) memory diminished with retention delay, and primacy (first item) memory…

To obtain evidence linking long-term potentiation (LTP) and memory, we examined whether LTP induction modifies functional relationship among neurons in the rat hippocampus. In contrast to neurons in low-frequency stimulated or AP5-treated slices, LTP induction altered "functional connectivity," as defined by the degree of synchronous firing, among…

Information that is spaced over time is better remembered than the same amount of information massed together. This phenomenon, known as the spacing effect, was explored with respect to its effect on learning and neurogenesis in the adult dentate gyrus of the hippocampal formation. Because the cells are generated over time and because learning…

One conditioned taste aversion experiment with rats assessed the impact of extinguishing a target conditioned stimulus (CS), S, in compound with a second CS, A, upon conditioned responding elicited by CS S when presented alone at test. Following initial conditioning treatment with CSs A and S, the experiment manipulated number of extinction trials…

The focus of this manual is the timber wolf and its experience in the United States. The activities are designed to enable students to gain a factual understanding of the timber wolf, question any misinformation they have learned regarding wolves, and learn to appreciate the wolf as a creature of nature rather than fear it as a creature of fairy…

Article investigated the pattern of results for three series of tests in which monkeys were deprived of sight of their limbs from birth. (Author/RK)

Visual memory in monkeys was examined under four different conditions, each with a separate group. (Editor)

Predictions of two-stage learning theories were evaluated by measuring observing responses which produced the discriminative stimuli for .5 sec. (Editor)

This study is concerned with the transfer of learned helplessness from one aversive motivator, shock, to another, frustration. (Author)

The mother of a deaf preschool girl recounts how a pet kitten found by her daughter has provided the occasion and motivation for much language practice. (GW)

While responses permitting no change in location are learned very slowly, responses that allow unambiguous flight from a dangerous location are learned very rapidly. Two experiments examine the possible reinforcing properties of the flight response in avoidance acquisition. (Author/RK)