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.     

Structures and strictures: Some functional limitations on the course of cognitive growth

A functional (as opposed to structural) theory of intellectual development is presented, and used to generate specific performance models for Piagetian tasks involving the control of variables. On the basis of these models, it is concluded that intelligent, field independent 7- and 8-year-olds should be able to acquire the control of variables scheme, even though they have not yet acquired either conservation of weight or the combinatorial system. Preliminary data (n = 52) are presented to support this conclusion. They are discussed with regard to Piaget's formal theory of intellectual development, and the functional limitations of development on learning.     

Analysis of memory codes and cumulative rehearsal in observational learning

The present study examined the influence of memory codes varying in meaningfulness and retrievability and cumulative rehearsal on retention of observationally learned responses over increasing temporal intervals. Symbolic codes combining meaningfulness with retrievability produced superior memory performances, but responses were poorly retained in symbolic representations containing only one of these properties. Individual response analysis further confirmed that the more meaningful the codes incorporating retrieval guides the better are modeled responses learned and retained. Cumulative rehearsal had differential effects on memory performances depending upon the serial input position of the responses and the form into which the modeled behavior was encoded. Code rehearsals facilitated retention of early and intermediate responses which were repeated more than later ones, but this was true mainly for codes vulnerable to loss. The overall findings provide further corroborative evidence that memory performances are governed more by information coding than by associative strengthening processes.