Time reproductions by H.M

Time reproductions by a subject with a severe memory loss were normal only for intervals less than 20 sec. For longer intervals, the reproduced intervals were roughly proportional to the square root of the standard intervals, plus 20 sec.     

A multidimensional scaling analysis of judged similarity of complex forms from two task situations

Ss provided judgments of pairwise stimulus similarities for 21 12-turn random forms in two experimental tasks: a scaling task, involving a variant of the method of graded dichotomies, and a sorting task, which simply required Ss to categorize the forms. The grouped data from both tasks, when analyzed using nonmetric multidimensional scaling techniques, yielded five-dimensional configurations with euclidean distances. The correspondence of these two spaces, assessed using canonical correlations, was extremely good. The psychological dimensions derived from both tasks were related to two sets of physical measures on the forms: the factor space suggested by Brown and Owen and a set of more basic physical measures. Physical cues of greatest importance involved size, dispersion, angularity, and rotation measures. The value of the tasks and the utility of the Brown and Owen measures were discussed.     

Reinforcement delay: some effects on behavioral contrast

Thirty five White Carneaux pigeons first received 20 sessions of non-delayed reinforcement according to a multiple variable-interval 1-min variable-interval 1-min schedule. For the remaining 15 sessions, subjects were assigned to one of five groups, with seven subjects per group. Four of these groups involved reinforcement according to the same multiple schedule as before, but reinforcement during one of the components was delayed for either 2.5, 5, 10, or 120 sec. The schedule for the fifth group was changed to multiple variable-interval 1-min extinction schedule of reinforcement. While some subjects in all groups showed behavioral contrast, it occurred more consistently in the groups involving extinction or the longer delays of reinforcement. Groups involving the various durations of delayed reinforcement or even extinction during the altered component did not, however, show a statistically significant difference in the amount of behavioral contrast. It was suggested that neither a reduction in reinforcement frequency nor response rate during the altered component is necessary to the production of behavioral contrast.     

Aversive aspects of a fixed-interval schedule of food reinforcement

The key pecking of pigeons was reinforced according to a fixed-interval schedule of reinforcement. The pigeons were also given the opportunity to attack a restrained target pigeon. The attack rates during the sessions of fixed-interval reinforcement were higher than during the operant level sessions in four of the five pigeons. Most attack occurred during the post-reinforcement pause in key pecking. It was suggested that a fixed-interval schedule of positive reinforcement possesses aversive properties, the most aversive of which are located during the post-reinforcement pause.     

A longitudinal study in a national sample of young farmers in the United States

This study is based on Project TALENT data collected in the last year of high school and five years beyond high school. Young men were classified as persisters in, dropouts from, and recruits to farming as a career. Those groups were compared with each other and with students in general. The most outstanding characteristic of young farmers in the United States is their relatively extensive background in agriculture, including father's occupation, high school curriculum, extracurricular activities in high school, work experience, and college major. Five years after high school, young fanners are more likely than students in general to have embarked on their life work and to have established their family. Differences in college attendance are consistent with this pattern. Despite incomes that are often relatively low, young farmers are not more dissatisfied with their work. The characteristics tapped by psychological tests appear to have few strong relationships to choice, satisfaction, and success in farming as a career.     

Lloyd Morgan's theory of instinct: from Darwinism to neo-Darwinism.

Darwin's proposal of two sources of instinct--natural selection and inherited habit--fostered among late nineteenth century evolutionists a variety of conflicting notions concerning the mechanisms of evolution. The British comparative psychologist C. Lloyd Morgan was a cardinal figure in restructuring the orthodox Darwinian conception to relieve the confusion besetting it and to meet the demands of the new biology of Weismann. This paper traces the development of Morgan's ideas about instinct against the background of his philosophic assumptions and the views of instinct theorists from Darwin and Romanes to McDougall and Lorenz.     

Children's understandings of the attributes of life

Previous investigations of children's understandings of the life concept have focused on their classifications of the life status of familiar objects. In this study, we attempted to examine more directly the processes by which children infer life status by examining their reasoning about unfamiliar objects. In Experiment 1, 4- to 11-year-olds and adults were asked to name attributes of living things to establish which attributes they associated most closely with life. Children age 7 and younger most often named attributes true only of animals but not of plants; older children more often named attributes true of both animals and plants. However, movement was the single attribute cited most frequently by children of all ages tested. In Experiment 2, 4- to 11-year-olds and adults were presented information about attributes of imaginary objects on a distant planet and were asked to infer if those objects were alive. Again, young children relied relatively heavily on qualities true only of animals but not of plants, whereas older children relied more on attributes true of both plants and animals. Also as before, movement was viewed as indicative of life at all ages tested. In Experiment 3, we examined the hypothesis that children discriminate among different types of motion and that the types of motion they associate with life are in fact typical of living things. Children ranging from age 5 through 11 were found to discriminate among different types of motion and to infer that objects were alive only when they showed the types of motion typical of living beings. The results of Experiment 3 allowed interpretation of seemingly conflicting results that have arisen in previous studies, as well as in Experiments 1 and 2 of the present study.     

Using FMRI to study the neural correlates of virtual reality analgesia

Excessive pain during medical procedures, such as burn wound dressing changes, is a widespread medical problem and is especially challenging for children. This article describes the rationale behind virtual reality (VR) pain distraction, a new non-pharmacologic adjunctive analgesia, and gives a brief summary of empirical studies exploring whether VR reduces clinical procedural pain. Results indicate that patients using VR during painful medical procedures report large reductions in subjective pain. A neuroimaging study measuring the neural correlates of VR analgesia is described in detail. This functional magnetic resonance imaging pain study in healthy volunteers shows that the large drops in subjective pain ratings during VR are accompanied by large drops in pain-related brain activity. Together the clinical and laboratory studies provide converging evidence that VR distraction is a promising new non-pharmacologic pain control technique.     

Convergence as a cue to depth

A test that presents conflicting monocular and vergence cues to depth shows that approximately two-thirds of the population can use convergence as a cue to depth. The remaining one-third apparently cannot use this cue. These differences in the role of convergence in depth perception reflect individual differences in the neural mechanisms underlying depth perception.