A direct comparison of four methods for eliminating a response

Thirty-two rats pressed one lever (lever A) on a VI 30-sec schedule of food reinforcement and were then shifted to one of four procedures for eliminating the lever A response: extinction, differential reinforcement of other behavior, reinforcement of a different response (pole pushing), and reinforcement of a similar response (pressing lever B). Effectiveness of a response-elimination procedure was measured by (1) how quickly lever A response rate fell to a low level when the procedure was in effect, (2) how much lever A responding recovered when the procedure was discontinued, and (3) how resistant lever A responding was to reinstatement when the VI reinforcement schedule was reimposed. No one method was superior by all three measures. Extinction produced the most variable behavior, while differential reinforcement of other behavior produced the least. Reinforcing alternative behavior produced the greatest recovery in the original lever A response when the response-elimination procedure was discontinued.     

Maintenance and generalization of trained metamnemonic awareness by educable retarded children

The majority of educable retarded children (young group, MA 6; old group, MA 8) required to estimate their memory span was found to be unrealistic estimators. Following training in span estimation the older subjects improved under both explicit and implicit feedback conditions, while younger children only benefited from explicit feedback. Three posttests of the effects of training revealed long-term (1-year) maintenance of training for older subjects but younger subjects showed post-test improvement only on an immediate test. While long-term maintenance was found for older subjects, generalization to similar span-estimation tests was not found. The utility of training metamnemonic knowledge which does not generalize was questioned and alternate training procedures were proposed.     

Origin of the speech apparatus and its reconstruction in fossils.

Renewed enthusiasm has produced provocative speculations in recent literature on the origin of speech. The purpose of the present investigation is to expose the adaptive renovations underlying the emergence of a “Vocal Tract” and from this to define its anatomical substrate which governs the biomechanics of speech production. The vocal tract is a double resonator tube coupled in series and composed of oral and pharyngeal cavities. Analysis is made of the crucial structural elements of this complex from detailed dissections in modern man and the study of modern and fossil hominid crania. The study focuses on relations of the skull base, jaw, hyoid bone and the contained tongue, pharynx and valvular devices, calling into question recent reconstructions built on classical Neanderthal skulls.     

An extension of construct validity for personality scales using twin-based criteria

A twin-based analysis of personality inventory scales yields information relevant to construct validity. If scales validly measure dimensions influenced developmentally either by environmental factors common to cotwins or by genetic similarities, these influences should be apparent in patterns of intraclass correlations and within-pair variance ratios for monozygotic and dizygotic pairs. Criteria for construct validity derived from adolescent twin statistics are illustrated with Wiggins' MMPI Content Scales. A type of discriminant validity indicates that some scales are not distinct in terms of the influences of familial similarity. Sex differences are examined.     

Influence of aging on recovery from aphasia in polyglots

We analyzed patterns of recovery, according to the rules of Pitres [1895, Revue de Medecine (Paris), 15, 873–899] and Ribot (1881, Les Maladies de la Memoire, Paris: Libraire Germer Baillere et Cie, pp. 146–147), in polyglot aphasics divided into subgroups by age. The rule of Ribot did not apply predictably for any age group. Pitres' rule clearly applied, but only for the nonelderly groups. Aging and its concomitant deterioration of recent memory seem to influence patterns of recovery from aphasia in polyglots.     

Semantic and acoustic processing in free and cued recall by educable mentally retarded adolescents

The abilities of educable mentally retarded adolescents to encode and retrieve words with semantic and acoustic cues were investigated in a free and cued recall task. On each of three trial blocks, seven groups of subjects were presented 20 unrelated stimulus words. Groups received either semantic, acoustic, or no encoding cues along with the stimuli. Free recall was requested from all subjects, followed immediately by a second period of either free recall or cued recall with the semantic or acoustic cues. Semantic cues were most effective when presented both at encoding and retrieval. The subjects were unable to use acoustic information as effective retrieval aids. Results were discussed in terms of encoding dimension dominance and mediational deficiencies.     

Autumn leaves and old photographs: The development of metaphor preferences

In order to determine the development of preferences for different types of metaphors, a metaphor preferences task was designed. Subjects at seven ages, from 6 through 20 years, received incomplete sentences followed by metaphorical and literal completions, and were asked to select their preferred completions. The pattern of preferences shifted with age. Metaphors based on grounds involving color or shape were preferred by the youngest subjects; metaphors based on movement or sound were preferred by subjects of intermediate age; and metaphors based on nonperceptual, conceptual grounds were preferred by the oldest subjects. At all ages the most frequently chosen metaphors were those based on a combination of two grounds (e.g., color and shape). Preference for literal completions declined with age, but there was an increase in literal selections in the 8th and 10th grades. This study demonstrates the systematic development of aesthetic preferences in the domain of figurative language.     

The effect of a commercial game on children's block design scores on the WISC-R IQ test

Two experiments investigated the extent to which 10-year old children's scores on the WISC-R Block Design subtest were affected by prior experience with a specific commercial game that involved blocks and matching patterns. Experiment 1 found that 12 10-year old children who happened to have experience with the particular commercial game scored approximately three scaled score points higher on the WISC-R Block Design subtest than 24 matched children without game experience. In Experiment 2, 24 children who did not have prior experience with this particular commercial game were randomly assigned either to a Game condition (involving two 15-minute sessions with the game) or to a No-Game condition (which involved no further game experience). Children in the Game condition subsequently increased their WISC-R Block Design scores more than children in the No-Game condition. Taken together, the experiments indicate that relatively brief interactions with a commercial game can cause a significant improvement in children's performance on an IQ subtest.     

Relational responses in tests of transposition with Rhesus monkeys

Three adult Rhesus monkeys (Macaca mulatta), one with nonrelated discrimination learning experience and two experimentally naive, were trained to discriminate between two simultaneously presented stimuli differing only in height. After exceeding the learning criteria on a VR 4 reinforcement schedule and considerable overtraining, subjects were tested for transposition. Both upward and downward and near and far tests were administered to determine the effects of distance from the original training pair on the amount of transposition. In these tests, each of the 24 stimulus pairs contained one or more novel stimuli. Training trials were interpolated to avoid extinction effects and measures were taken to avoid motivational deficits or differential rewards during testing. All three subjects responded relationally at far as well as near distances from the original training pair. Stimulus generalization, on the basis of increments of association, was found to be an inferior explanation for these data. Slight decrements on far tests can be better explained in terms of the learning-performance distinction.     

Children's understanding of food and its functions: A preliminary study of the development of concepts of nutrition

Children's developing conceptions of how the body functions nutritionally were examined. Two different tasks provided converging findings. One task asked children to judge the causes of certain end states (e.g., why X is fat). The second task asked children to judge the result of certain contrasting diets (e.g., twin-1 eats twice as much candy as twin-2). The results evidenced; (a) systematic misconceptions on the part of kindergarteners that were overcome by sixth grade; and (b) other fairly sophisticated conceptions present even at the youngest ages tested. The research provides a needed first step toward describing the naive theories of nutrition possessed by children at different ages. Knowledge of childrens' theories of nutrition are essential for optimal planning of curricula and methods in nutrition education.