Category discrimination by pigeons using five polymorphous features

Eight pigeons were trained to discriminate between sets of color photographs of natural scenes. The scenes differed along five two-valued dimensions (site, weather, camera distance, camera orientation, and camera height), and all combinations of the feature values were used. One value of each dimension was designated as positive, and slides containing three or more positive feature values were members of the positive stimulus set. Thus, each feature had an equal, low, correlation with reinforcement, and all features had zero correlations with each other. Seven of the 8 pigeons learned this discrimination, and their responding came under the control of all five features. Within the positive and negative stimulus sets, response rates were higher to stimuli that contained more positive feature values. Once discrimination had been achieved, reversal training was given using a subset of the slides. In this subset, only a single feature was correlated with reinforcement. All pigeons learned this reversal successfully and generalized it to additional photographs with the same feature content. After reversal, the original reinforcement contingencies were reinstated, and training was continued using all the slides except those that had been used in reversal. Reversal generalized to these slides to some extent. Analysis of the response rates to individual slides showed that, compared with prereversal training, only the feature that had been subjected to reversal contingencies showed a reversed correlation with response rate. The remaining features showed the same correlation with response rate as they had before reversal training. Thus, reversal on some members of a category following category discrimination training led to generalization to stimuli within the category that were not involved in the reversal, but not to features that were not reversed. It is therefore inappropriate to refer to the pigeons as learning a concept.     

Culture wars: American moral divisions across the adult lifespan

Sociologists have argued that the public moral debate in contemporary America is characterized by a “culture war,” pitting “orthodox” and “progressivist” groups against one another (Hunter, 1991). This study addressed whether the culture war is evident in the moral thinking of ordinary Americans, and whether age-related patterns exist. Sixty fundamentalist Baptists (orthodox) and 60 mainline Baptists (progressivist) evaluated and reasoned about moral issues such as divorce and abortion. Each group was divided evenly into three age groups copsisting of young, midlife, and older adults. Moral reasoning was analyzed in terms of Shweder's (1990) ethics of autonomy, community, and divinity. Within all three age groups, progressivists used the ethic of, autonomy more than orthodox participants. Orthodox participants used the ethic of divinity more than progressivists. Orthodox and progressivist groups did not differ much in their use of the ethic, of community. Very few age group differences were found within the orthodox and progressivist groups. It is concluded that morality is conceived of in markedly different wasy by orthodox and progressivist groups, and that these conceptions are consistent across age groups.     

Building and Maintaining Clinical Programs

This paper describes the basic elements of practice development and management within the academic medical setting. These include assessment of the market environment, both in the community and within the medical setting, product development, marketing, budget basics, quality, managed care negotiations, and finding time to do research in a financially-driven health care system.     

1—5岁儿童使用双宾结构状况的考察

本文对1—5岁汉族儿童使用双宾结构的状况进行了考察。首先对儿童语言中双宾结构的结构类型、句法功能及其发展状况进行了描述分析;在此基础上,讨论了儿童习得汉语双宾结构的机制。     

婴儿共同注意能力的发展

本研究采用严格的实验室测验法,从年龄趋势、学习能力、性别差异三方面考察了8～11个月婴儿共同注意能力的发展。结果表明：1）婴儿的共同注意力在8～11个月间逐步提高,9个月左右出现显著的发展性变化,但1岁以前,该能力的发展水平都较低;2）就共同注意而言,婴儿具有从练习经验中学习的可能性,且学习能力存在年龄差异,8个月的婴儿基本不能从练习中受益,而8个月以上的其他三组婴儿在练习后共同注意水平都有不同程度的提高;3）总体而言,女婴共同注意能力的发展水平显著地高于男婴。     

BEHAVIORAL CUSPS: A DEVELOPMENTAL AND PRAGMATIC CONCEPT FOR BEHAVIOR ANALYSIS

Most concepts of development explain certain behavior changes as products or markers of the invariable succession of emerging periods, stages, refinements, or achievements that define and order much of an individual's life. A different but comparable concept can be derived from the most basic mechanisms of behavior analysis, which are its environmental contingencies, and from its most basic strategy, which is to study behavior as its subject matter. From a behavior-analytic perspective, the most fundamental developmental questions are (a) whether these contingencies vary in any systematic way across the life span, and thus make behavior change in a correspondingly systematic way; and (b) whether some of these contingencies and their changes have more far-reaching consequences than others, in terms of the importance to the organism and others, of the behavior classes they change. Certain behavior changes open the door to especially broad or especially important further behavior change, leading to the concept of the behavioral cusp. A behavioral cusp, then, is any behavior change that brings the organism's behavior into contact with new contingencies that have even more far-reaching consequences. Of all the environmental contingencies that change or maintain behavior, those that accomplish cusps are developmental. Behavior change remains the fundamental phenomenon of development for a behavior-analytic view; a cusp is a special instance of behavior change, a change crucial to what can come next.     

Implications of college-age narcissism for psychosocial functioning at midlife: Findings from a longitudinal study of women

Positive and negative implications of two types of college-age narcissism on psychosocial functioning at midlife were studied in a longitudinal sample of women. Both types were scored with self-report measures when the women were, on the average, age 21. Throughout the first half of their adult life, high scorers on covert narcissism presented themselves as lacking in confidence and having low morale; high scorers on overt narcissism described themselves as wanting admiration, being independent, and being forceful. Positive outcomes associated with covert narcissism included the development of insight and of a differentiated sense of the self and, in the case of overt narcissism, entailed an involvement in high-status and creative work careers. At midlife, high scorers on covert narcissism experienced negative affect and feelings of being neglected, whereas high scorers on overt narcissism experienced family conflict and problems with impulse control. The personality characteristics associated with both types of narcissism remained stable from the early 20s to early 50s.     

学前儿童对汉语副词的理解和运用

在汉语中,副词是一种比较独特的词类,它没有具体形象的物体可作为理解支柱,因而儿童对它的掌握较晚。在各类副词中,５、６岁儿童对范围副词的理解最佳,时间副词次之,程度副词最差。三者的差异均有非常显著性意义。即使在每一类副词中,由于儿童概念发展的不均衡性,掌握的顺序也有先后。     

Converging measures of speech segmentation in preverbal infants

Two studies using novel extensions of the conditioned head-turning method examined contributions of rhythmic and distributional properties of syllable strings to 8-month-old infants' speech segmentation. The two techniques introduced exploit fundamental, but complementary, properties of representational units. The first involved assessment of discriminative response maintenance when simple training stimuli were embedded in more complex speech contexts; the second involved measurement of infants' latencies in detecting extraneous signals superimposed on speech stimuli. A complex pattern of results is predicted if infants succeed in grouping syllables into higher-order units. Across the two studies, the predicted pattern of results emerged, indicating that rhythmic properties of speech play an important role in guiding infants toward potential linguistically relevant units and simultaneously demonstrating that the techniques proposed here provide valid, converging measures of infants' auditory representational units.