Spontaneous and learned turning behaviour in food- or water-restricted hooded rats

Some laboratory studies have suggested that whereas food restriction in animals leads to response alternation (behavioural flexibility), water restriction induces perseverative, stereotyped responding. Hooded rats, restricted to 1 hour per day access to either food or water, were tested on a radial-arm maze (using a procedure that eliminates algorithmic response strategies), for alternation in a 3-arm maze (both when the maze was familar and unfamilar, and with or without differential reward) and a 2-choice maze in which some animals were taught to alternate direction of turn, and others to perseverate. Both groups performed the radial-arm maze task competently and spontaneously alternated at a high rate. In the learned task, food-restricted rats were slower than water-restricted to reverse a consistent direction of turn; in the alternation condition, water-restricted rats developed a temporary, but strong, directional bias when making their first choice each day. Water-restricted subjects took water more readily than food-restricted took food when initially introduced to the apparatuses, but there was no consistent difference in motivation in the two conditions. The results provide little support for the notion that distinct cognitive-motivational states or behavioural strategies are induced by food- and water-restriction.     

Redundant publication in biomedical sciences: Scientific misconduct or necessity?

Redundant publication in biomedical sciences is the presentation of the same information or data set more than once. Forms of redundant publication include “salami slicing”, in which similar text accompanies data presented in disaggregated fashion in different publications and “duplicate or multiple publication” in which identical information is presented with a virtually identical text. Estimates of prevalence of the phenomenon put it at 10 to 25% of published literature. Redundant publication can be considered unethical, or fraudulent, when the author(s) attempt to conceal the existence of duplicate publication from editors and readers. Redundant publication in the area of clinical trials is potentially dangerous as it tends to overestimate the effects of interventions. The scientific community at large and governments should take urgent steps to safeguard the public from the possible effects of fraudulent multiple publications.     

The effect of a teacher's presence on the classroom behavior of conduct-problem children

Six institutionalized conduct-problem children performed in a classroom under three reinforcement conditions: (1) noncontingent reinforcement: (2) reinforcement for being on task and (3) reinforcement for the accuracy and rate fo their academic behavior. Within each of these conditions, the teacher was either present throughout the class session or absent for a portion of the session. In the teacher's absence, on-task behavior was markedly reduced and disruption was markedly increased, regardless of the reinforcement condition in operation. In contrast, the teacher's absence had no effect on academic accuracy and had a major effect on academic rate only when reinforcement was delivered noncontingently. Furthermore, the extent to which the children became disruptive in the teacher's absence was reduced when reinforcement was contingent upon academic accuracy and rate, instead of being contingent upon being on task or delivered noncontingently. It is suggested that the reinforcement of academic behavior, rather than on-task behavior or classroom social behavior, not only will improve the latter behaviors as well, but possibly also make them less dependent upon the presence and continued surveillance of the teacher.     

Luminance control of a small computer CRT display: A very cheap technique

An inexpensive way to produce continuous variation in the luminance of a computer-controlled CRT display is described. One application of that system to the study of motion-analyzers in human vision is discussed briefly.