The within-list distributed practice effect: Tests of the varied context and varied encoding hypotheses

The present studies provided separate tests of the varied context and varied encoding hypotheses of the MP-DP effect. The investigation of varied encoding used an incidental learning procedure in which the nature of the orienting task was manipulated such that the subject attended to different attributes of words (varied encoding) or only one attribute (same encoding). While the prediction that the recall of MP-DP items should be comparable under comparable levels of encoding was not supported, differences were obtained in recall of items under same and variable orienting task conditions. An MP-DP effect was obtained under the incidental learning procedure. Tests of varied context involved the presentation of target items in list contexts which were the same or different from list contexts on previous occurrences of the item. The prediction that recall of items surrounded by different context should exceed that of items surrounded by the same context was not supported.     

Effects of educational and career exploration system on vocational maturity

An experimental group of 792 tenth graders spent from 1 to 17 hr (average 3 hr) on ECES, a computer-based educational and occupational exploration system.Gains on a test of vocational maturity administered at the beginning and end of the school year were compared with a control group of 1453 tenth graders, matched on relevant variables. ECES users showed larger gains than nonusers in (1) degree of planfulness and (2) knowledge and use of resources for career exploration, as measured by the Career Development Inventory, not in information about education, occupations and career decision making. Gains were related to amount of time spent on ECES but male-female differences were not exhibited.     

Repeated acquisition of response sequences: stimulus control and drugs.

Pigeons obtained food by making four responses on three keys in a specified sequence, e.g., left, right, center, right. Under the "tandem-learning" condition, all three keys were the same color throughout the response sequence, and the sequence was changed from session to session. After total errors per session (overall accuracy) and within-session error reduction (learning) had stabilized, the effects of varying doses phenobarbital and chlordiazepoxide were assessed. For comparison, the drug tests were also conducted under a "tandem-performance" condition, in which the response sequence was the same from session to session, and under corresponding "chain-learning" and "chain-performance" conditions, where different colored keylights were associated with the response sequence. Under all four baseline conditions, the largest dose of each drug impaired overall accuracy. Under the two learning conditions, the error rate decreased across trials within each session, but the degree of negative acceleration was less in the drug sessions than in the control sessions. In contrast, under the two performance conditions, the error rate was relatively constant across trials, but was higher in the drug sessions than in the control sessions. Of the four baselines, the chain-learning condition was the most sensitive to the drug effects.     

Presentation of a flashing light following training produces amnesia

Long-Evans rats given exposure to a flashing-light stimulus following one-trial fear conditioning showed amnesia relative to controls not given the flashing-light experience. Together with previous results obtained in this laboratory, it is apparent that the flashing light modulates memory processing.     

Category typicality effects in children's memory performance: Qualitative and quantitative differences in the processing of category information

Kindergarten, third, and sixth graders (6, 9, and 12 years of age, respectively) received a cue-at-input/cue-at-output recall task, using category typical and atypical items that were based on either (1) children's conceptions of item typicality, or (2) adults' conceptions of item typicality. At each grade level, recall was greater with the child-defined lists than with the adult-defined lists, and typical items were recalled to a greater extent than atypical items. Further analyses items were recalled to a greater extent than atypical items. Further analyses revealed that the recall of typical items varied as a function of children's typicality ratings of items, and that the “typicality effect” in the adult-norm condition was due primarily to the childrennot realizing that many of the atypical items were appropriate category exemplars. In contrast, typicality effects in the child-norm condition were attributed to qualitative differences in the judged “goodness of example” of the typical and atypical items. The results were discussed in terms of the appropriateness of typicality as a dimension of children's natural language concepts, the role of age differences in knowledge base in affecting performance on a cognitive task, and of the importance of using child-generated norms in studies of children's processing of category information.     

Developmental trends in children’s typicality judgments

Category typicality norms from 12 natural language categories are presented for kindergarten, third-grade, sixth-grade, and college students. Subjects first selected examples of familiar word concepts and rated them on a 3-point scale in terms of category typicality. Age differences in the percentage of items included as category members were found primarily for the less typical items, with inclusion rates varying as a function of both age and typicality level. The absolute level of typicality judgments increased with age, although correlations between the children’s and college students’ ratings were generally significant for all three children’s groups, with average correlations increasing somewhat with age. It was suggested that the rating data would be useful to developmental investigators interested in children’s processing of category information.     

Population psychology in perspective(1)

Many aspects of population, from fertility regulation to migration, may be viewed as examples of human behavior occurring within a particular socio-economic and environmental context, and thus appropriate for psychological research. Especially considered in this paper are (1) the current status of population growth and the importance of population processes as research topics for psychologists; (2) basic assumptions concerning the complementarity of behavioral and biomedical sciences in population research; (3) behavioral science contributions, specifically from psychology; and (4) recommendations for cooperative multidisciplinary efforts.     

Responding maintained by the opportunity to attack during an interval food reinforcement schedule

Pigeons responded in a two-key situation. Responses on the right key (food key) were reinforced with food presentation on a response-initiated fixed-interval schedule, (i.e., first response after a fixed period of time was reinforced); responses on the left key (target key) were reinforced on a fixed-ratio schedule (i.e., every nth response was reinforced) with the presentation of a target bird that could be attacked. When the interval value of the food reinforcement schedule was varied from 1 min to 5 min, both the rate of attack responding on the target bird and the rate of responding on the target key were a function of the interval value. Responding on the target key was not maintained by the stimulus change associated with target availability, and was successively extinguished and reconditioned by removing and returning the target bird to the restraining box. When food was delivered independently of behavior, responding on the target key either remained unchanged or decreased, but was not eliminated. Responding on the target key was not maintained in the absence of an intermittent schedule of food presentation.     

Assertive training: An adjunct to fluency shaping

“Assertive Training” has been utilized as an adjunct therapy in a six week residential program at Walter Reed Army Medical Center. The speech pathology staff in conjunction with the psychology staff determined that a persistent problem with long term success after patients were dismissed from therapy was largely due to a “behavioral deficit” in their interpersonal verbal confrontations. The anxiety resulting from such communication failure simply chips away at the self confidence needed to maintain a working level of fluency, resulting in a “snowballing” effect back to dysfluency.

Thus, the goals and procedures of assertive training for stutterers are discussed as a means to shape more effective skills in relating to others in difficult situations. Pre, post and six month follow-up data are presented.