Distance estimation from cognitive maps

Four experiments investigated map clutter as a source of distortion in subjects' estimates of distance. In Experiments 1 (incidental learning) and 2 (intentional learning), subjects estimated distances between pairs of points on a memorized map. In both experiments, estimates increased as a linear function of the number of intervening points along the route. In Experiment 3, subjects estimated distances while viewing the map. The effect of clutter was reduced but not eliminated. In Experiment 4, the clutter effect was demonstrated using subjects' preexperimental knowledge of United States geography. Psychophysical power functions relating true to estimated distance provided a good fit to both memory and perception data. These results suggest an analogy between perceptual and memorial processes of distance estimation. A model proposed to account for the data assumes that subjects perceptually scan a route (or image of a route) from start to destination and use scan duration to determine path distance.     

The clinical validity of the process for assessment of effective student functioning

This report presents the results of a study of the clinical validity of A Process for Assessment of Effective Student Functioning. A clinical team composed of social workers, psychologists and psychiatrists saw 300 representative second and fifth grade children, rated them on interview and test protocols, and summarized the evaluation by single and summary qualitative judgments. The clinical validity criteria were established on the basis of independent evaluations of the home environment, the intellectual and emotional status of the child, and the child's ego functioning. Finally, a clinical criterion score was derived from the overall evaluation of the effectiveness of each subject by each member of the team. The multiple correlations of the three screening measures with the clinical criterion score ranged from .49 to .55 for second grade and fifth grade boys and girls. The clinical criterion scores of children who were screened by the recommended multiple cut-off procedure showed that none of the screened group was rated by the clinicians to have better than average adjustment. The multiple correlation and multiple cut-off procedure showed that the Process was valid for predicting independent clinical judgments of the status of these children. Furthermore, the Process was far more efficient in locating potentially handicapped children than either a carefully designed teacher nomination procedure or teacher referral.     

Comprehension of gerundive constructions by Broca's aphasics

Eleven diagnosed Broca's aphasics were tested for comprehension of sentences containing gerundive constructions. Results showed that, as a group, these patients were sensitive to grammatical distinctions signaled by “function” words, contrary to the predictions of some current theories about the specific deficits exhibited in this syndrome. Further analysis showed that the patients fell into two subgroups, one which exhibited sensitivity to the distinctions in normal grammar, and another which exhibited no sensitivity to such distinctions. This suggests that the syndrome may have different manifestations in different populations—patient age is suggested as a possible means for distinguishing the two groups. Suggestions for further research into the nature of the comprehension deficits exhibited by Broca's aphasics are made.     

Effects of context-induced processing operations on semantic information acquired from discourse

Effects of context on processes involved in understanding discourse were investigated. An experimental context designed to directly affect discourse processing by inducing subjects to generate inferences involving text content was compared to a context in which subjects simply listened to and recalled the content of a text. The extent of inferential discourse processing was estimated from derived semantic information in subjects' text recalls. The experimental context produced effects on inferred and other derived information in subjects' text recalls which were predicted from a constructive model of discourse processing. Also consistent with this model, the amount of derived information increased with repeated exposures to the text. In a third condition, subjects repeatedly listened to the text in the experimental context, but only recalled it once on the last trial. The context produced very substantial effects on proportions of derived information under this condition. Context effects were still present one week later.     

Representing logical and semantic structure of knowledge acquired from discourse

A network model of logical and semantic structures from which speakers or writers generate linguistic messages at the discourse level is presented. While linguistic structures were considered in developing the model, the semantic and logical networks are defined without reference to linguistic structures and thus may be used to represent knowledge structures acquired from both linguistic and nonlinguistic sources. A second problem addressed is that of determining what logical and semantic information is acquired when a text is understood. To assess acquired knowledge, a procedure is presented for coding a subject's verbal reconstruction of knowledge acquired from a presented text (or other input) against the logical and semantic structure from which the text (or other input) was derived. The procedures are illustrated using data obtained from children who were asked to “retell” simple narrative stories.     

Some conditions for the dissociation of consummatory and instrumental behavior in rats

To investigate whether consummatory and instrumental behavior depend upon different motivational factors, rats were trained to press a bar for saccharin solution, then given various treatments designed to reduce the palatability of saccharin, and finally tested for bar-pressing in extinction and for free intake of saccharin. Prefeeding with dextrose, prefeeding with saccharin, and association of saccharin with injections of lithium chloride all reduced intake of saccharin compared to control treatments, but only prefeeding with dextrose also reduced barpressing in extinction. Thus, performance of an instrumental response may depend upon need for food rather than appetite for it.     

An attitude profile for studies of population psychology

Attitudes toward specific issues in population covary, but are independent enough to warrant separate assessment. Identifiable components include family planning, abortion, contraception, and population management. Modernity may be defined as a norm-setting factor, establishing a baseline around which the four other dimensions may vary. A system of beliefs will be more or less in phase or out of phase depending on the congruence between modernity and the other four indices. Scales to assess each factor were developed, and an attempt was made to minimize unwanted or artifactual variance pertaining to generalized distrust or misanthropy. Five case vignettes were given to illustrate the personological implications of contrasting profile configurations.