Naive beliefs in “sophisticated” subjects: misconceptions about trajectories of objects

University students were asked to solve simple problems about the trajectories of falling objects. A majority of the students revealed a variety of misconceptions about motion. However, the few basic patterns of responses produced by the subjects suggest considerable commonality in the types of naive physical “laws” people develop on the basis of everyday experience with the world.     

The personality characteristics of the rigid learner

The present research investigated the personality dimensions concomitant with learner's cognitive rigidity. The results showed a highly reliable multiple relationship between rigidity scores and dimensions of IPAT's 16PF. Specifically, the personality dimensions of tenseness, compulsivity, group dependency, absent mindedness, sensitivity, and emotional stability explained 36% of the variability in subjects' increasing levels of cognitive rigidity. The results were interpreted as showing a pervasive use of stereotype behavior as a coping strategy in dealing with a greater amount of anxiety concomitant with cognitive rigidity.     

Resistance to satiation: Reinforcing effects of food and eating under satiation

It has been shown previously that rats which have learned a response when hungry will continue to make that response when tested satiated, a phenomenon labeled resistance to satiation. Here we showed that rats which were previously trained hungry will learn a new response for the opportunity to consume pellets in a new situation when tested satiated. In four experiments various groups received each of the components of the training given when rats learn an instrumental response when hungry. Rats were placed in the goalbox of a straight alley and given food pellets when hungry or were hungry only in their home cages prior to running a straight alley in the satiated test in Experiment 1. In Experiments 2, 3, and 4 learning of a differential conditioning problem for pellets in S+ (nonreward in S?) was measured in the satiated test. Groups given pellets in their home cages when hungry with or without alley exposure learned to run more rapidly in S+ than in S? in the satiated test phase. The tendency to eat pellets in the apparatus and the reinforcing effect of eating the pellets was larger for rats which ate the pellets when hungry in their home cage than for rats which ate the pellets when satiated in their home cage. Being hungry in the home cage with no pellets was not sufficient to produce eating or running for pellets in the satiated test, indicating that any inherent reinforcing effect of the pellets is not sufficient to produce eating or running, and that incomplete satiation cannot account for the learning. These data indicate that a reinforcing effect of eating pellets under satiation is an important determiner of resistance to satiation.     

Duration discrimination is better with food access as the signal than with light as the signal

In Experiment 1 a go/no-go discrimination procedure was used to compare control of five pigeons' keypecking by food-access duration with control by light duration. Pecks to an illuminated key were reinforced with grain following 10-sec presentations of food access or houselight, but not after 5-sec presentations of either stimulus. Each subject discriminated food-access duration faster and to a greater degree than light duration. In four between-subject replications, pigeons discriminated food-access duration better than the duration of a localized light, the feeder light and a keylight, and with either water or food as reinforcement. In Experiment 2 control by durations of food access and light was compared using a conditional right-left choice procedure (two pigeons), and a delayed symbolic matching-to-sample procedure (six pigeons). Under both, choice accuracy again was higher on food-access trials. The results of Experiment 3, in which two pigeons received generalization trials with durations of food access and light that were intermediate to the training values, confirmed that responding was controlled by the duration dimension of both food access and light. The superior control by food access is consistent with previous evidence that food is an effective and memorable stimulus, possibly because of its biological importance. These results also provided empirical support for the commonly made assumption that stimuli differ in effectiveness. As well, the results show that the stimulus to be discriminated can play an important role in the accuracy of duration disciminations, a fact which has implications for the study of temporal discriminations in animals.     

An investigation of repetition and language processing in a case of conduction aphasia

A study is reported of a single case of conduction aphasia. A battery of tasks designed to investigate the parameters of the patient's severe repetition deficit is supplemented by tests of several language functions. The results provide extensive information on a wide range of the patient's language abilities and are used to evaluate the adequacy of four models that have been offered to account for conduction aphasia. An argument is made in support of the suggestion that the syndrome of conduction aphasia should be divided into two subgroups based on patients' ability to select and realize phonemes in speech output. It is concluded that the best explanation for the disorder of patients with repetition deficit but without significant speech output problems is the hypothesis that repetition ability is compromised by a pathological limitation of auditory-verbal short-term memory. This hypothesis is extended to account for the pattern of results obtained in the language tasks.     

Written language acquisition after left or right hemidecortication in infancy

When written language is acquired in only one hemisphere because of hemidecortication in infancy, the left hemisphere is superior to the right at using morphophonemic rules to read and spell unfamiliar words, and at exploiting the structure of sentence units to achieve rapid reading of meaning in prose. The ability to learn names for logographs, however, is better in the right hemisphere than in the left. The greater mastery of written language in the left hemisphere is a result, not of an enhanced facility for making cross-modal associations between sounds and signs, but of a superior access to the morphophonemic rule system and the higher-order textual constraints of English.     

Vocational development in early childhood: An examination of young children's expressions of vocational aspirations

Vocational aspirations were investigated in a sample of 282 children between the ages of 3 and 6. Age comparisons suggested that one aspect of vocational development in early childhood involves mastery of the task of projecting oneself into the future and conceiving of oneself as one day achieving adult status. Race comparisons indicated that urban blacks were less mature than urban whites in terms of mastery of the vocational projective task seen as characteristic of this developmental period. No significant sex differences were found in rate of development. However, there were indications that the pattern of vocational projection differs for males and females and that females undergo occupational foreclosure earlier than their male peers. Implications for vocational development theories are discussed.     

Partial reward training level and reward magnitude: Effects on acquisition and extinction

Two groups of 10 rats each received either a large magnitude (0.90 g) or a small magnitude (0.18 g) of partial reward (PR) and seven successive acquisition-extinction sessions in the runway. The large magnitude PR group ran much faster than the small magnitude PR group in the early acquisition sessions with differences between the groups declining over sessions. In the early extinction sessions, the large magnitude PR group showed greater resistance to extinction than the small magnitude PR group, but in the late extinction sessions this relation reversed itself. Finally, resistance to extinction decreased over sessions, this decrease being greater under a large than under a small magnitude of PR.