Successive independence and behavioral contrast in a closed economy.

Two pigeons had access to multiple concurrent schedules of reinforcement for 24 hours per day in their home cages. The variable-interval schedules comprising the multiple concurrent schedules were varied across 16 conditions. In three sets of conditions, one schedule was varied while its concurrent alternative and the concurrent schedules in the other component were held constant. Behavioral contrast was observed; that is, as the rate of reinforcement arranged by the varied schedule decreased, response rates on the constant schedules typically increased. These conditions formed part of two larger sets of conditions in which the concurrent schedules in one multiple-schedule component remained constant while the concurrent schedules in the other component were varied. Successive independence was found, in that behavior allocation during the constant component did not vary as a function of the reinforcer ratios in the varied component. Successive independence between components in multiple concurrent schedules is a robust result that occurs in closed economies and under conditions that promote behavioral contrast.     

A thought on the nature of psychoanalytic theory

In this paper I suggest that much of recent experiment in analytic theory, even widely diverse approaches, has a common denominator the problem of the conceptual vacuum created by the shift away from a central creative position of the idea of psychic mechanisms. I try to illustrate, by comparing theories of Bion and George Klein, that this movement seems to point in the direction of considering now what is uniquely psychoanalytic about our theories. I content that what is unique about psychoanalytic theories is that they are involved in the experiential core-function of the applied science by becoming internalized and used symbolically to aid the analyst inwardly to endure persecutory anxiety and loss of the sense of objective reality, and so maintain the analytic position.     

Signal-detection analysis of luminance generalization in goldfish using latency as a graded response measure

ROC curves were determined from response latencies of goldfish in a single-stimulus generalization task. The resulting functions were similar to ROC curves obtained by rating methods with human Os.     

An investigation of the relationships between problem solving strategies, representation and memory

There has been considerable debate in recent years about the status of “imagery” in problem solving. The present experiment attempts to show that while subjects may employ representational strategies when they first encounter a class of problems, they abandon such strategies as they gain experience with the problems. It does this by asking subjects to answer unexpected questions which are based upon the information which they have just used to solve a problem. The hypothesis, which is supported by the results, is that increasing experience with problems will be paralleled by a decreasing ability to answer unexpected questions. The experiment also shows that such effects are not attributable to a build-up in proactive interference.     

Peak shift as a function of multiple schedules of reinforcement

Pigeons were trained to respond to two stimuli on the wavelength continuum, 550 nm and 570 nm, each correlated with an independent schedule of reinforcement. The multiple schedule component in effect during 550 nm (S1) was always a variable-interval 1-min. During the 570-nm stimulus (S2) the second component of the schedule was either variable-interval 30-sec, 1-min, 2-min, 5-min, or extinction for different groups of birds. Generalization gradients were obtained after this training, with the following results: (1) response rate to S1 during training was related to the reinforcement frequency associated with S2; the distribution of responding during generalization testing was a function of the schedules of reinforcement used during training and the response rates they produced. Decreases in the relative frequency of reinforcement correlated with S2 resulted in increases in the distribution shift of responses away from S2 during generalization testing.     

Adolescent reading skill and engagement with digital and traditional literacies as predictors of reading comprehension

This study investigates the concurrent predictors of adolescent reading comprehension (literal, inferential) for fiction and non‐fiction texts. Predictors were examined from the cognitive (word identification, reading fluency), psychological (gender), and ecological (print exposure) domains. Print exposure to traditional and digital texts was surveyed using a diary method of reading habits. A cross‐sectional sample of 312 students in early (11–13 years) or middle adolescence (14–15 years) participated from a range of SES backgrounds. Word identification emerged as a strong predictor of reading comprehension across adolescence and text genres. Gender effects favouring female students were evident for reading frequency but not for reading skill itself. Reading habits also differed, and comprehension advantages were observed among females for fiction and males for non‐fiction. Age effects emerged for reading frequency, which was lower in middle adolescence. Although more time was spent on digital than on traditional texts, traditional extended text reading was the only reading habit to predict inference‐making in comprehension and to distinguish skilled from less skilled comprehenders. The theoretical and educational implications of these results are discussed.