Stimulus effects on concurrent performance in transition

Six experimentally naive pigeons were exposed to concurrent variable-interval variable-interval schedules in a three-key procedure in which food reinforcement followed pecks on the side keys and pecks on the center key served as changeover responses. In Phase 1, 3 birds were exposed to 20 combinations of five variable-interval values, with each variable-interval value consistently associated with a different color on the side keys. Another 3 pigeons were exposed to the same 20 conditions, but with a more standard procedure that used a nondifferential discriminative stimulus on the two side keys throughout all conditions. In Phase 2, the differential and nondifferential stimulus conditions were reversed for each pigeon. Each condition lasted for one 5-hr session and one subsequent 1-hr session. In the last 14 conditions of each phase, the presence of differential discriminative stimuli decreased the time necessary for differential responding to develop and increased the sensitivity of behavior to reinforcement distribution in the 1st hr of training; during the last hours of training in each condition, however, the effects of the differential discriminative stimuli could not be distinguished from the effects of reinforcement distribution per se. These results show the importance of studying transitions in behavior as well as final performance. They may also be relevant to discrepancies in the results of previous experiments that have used nonhuman and human subjects.     

4-5年级学生的空间表征与几何能力的相关性研究

本研究是“学生空间能力和几何能力关系”研究的一部分,以小学4、5年级学生为被试(共117人),以空问表征能力测验和几何能力测验为测验工具,初步探讨了学生空间表征与几何能力的关系。对数据结果的分析表明:①就总成绩而言,五年级学生的空间表在成绩明显高于四年级学生的成绩,但并不是空间表征的所有方面都存在着显著的年级差异;②就空间测验的总成绩而言,无论是四、五年级分别考察还是总起来考察,空间成绩与几何成绩之间的相关显著,但就各个分项而言,并不是空间测验的各项都与几何测验成绩有显著相关;学生的几何成绩在一定程度上可通过回归方程:Y_i=0.5736X_i+0.7635加以预测。     

Technology and the structuring of jobs: Employee satisfaction,performance, and influence

This research investigated the relationships between technology, interdependence, job characteristics, and employee satisfaction, performance, and influence. Technology was operationalized at the individual level of analysis to include the dimensions of input uncertainty, conversion uncertainty, and output uncertainty. Pooled, sequential, and reciprocal interdependence was assessed. The results indicated that input and conversion uncertainty and interdependence were strongly related to such job characteristics as autonomy, skill variety, task identity, task significance, and task feedback. While the job characteristics related positively to employee satisfaction, input and conversion uncertainty related negatively to satisfaction, thus creating a mutual suppression effect. Although the uncertainty dimensions did not relate significantly to performance, there is some evidence that this negative relationship was being suppressed by the positive relationship between job characteristics and performance. Both the job characteristics and the technology dimensions related positively to influence. Results were discussed in terms of appropriate matches between technology and job characteristics.     

The effects of social motives on behavior in social dilemmas in two cultures

Subjects in Santa Barbara, California, and Groningen, The Netherlands, participated in a seven-person social dilemma game, presented in terms of a conservation of resources problem. Prior to their decision making in the social dilemma game, subject's social motive (altruistic, cooperative, individualistic, competitive) was assessed by means of two different classification procedures. On the basis of previous research findings American subjects were expected to display relatively more competitive social motives, and Dutch subjects relatively more cooperative ones. However, no indications of crosscultural differences were found neither with regard to the distribution of social motives nor with regard to the amount of resources taken for self in the social dilemma game. In both locations, competitive subjects took most resources for self, individualistic subjects took next most, cooperative subjects took less than individualists, and altruistic subjects took the least. In addition to predictive validity, indices of the convergent validity of two social motive assessment procedures were described.     

The pathological left-handedness syndrome

A clinical syndrome of pathological left-handedness (PLH) is proposed to identify the pattern of correlative changes in lateral development associated with early brain injury in some manifest left-handers. This syndrome is believed to be caused by a hemispheric lesion that is predominantly left-sided (or bilateral asymmetric), which onsets before Age 6, and which encroaches upon the critical speech zones of the frontotemporal/frontoparietal cortex. The pattern of changes may include any or all of the following features: shifts in manual dominance, trophic changes in the extremities, transfer of hemispheric speech, and/or intrahemispheric reorganization of visuospatial cognitive functions. Although some of these correlates of PLH have long been known, they have not been recognized as an interrelated pattern of traits that constitute a clinical syndrome. Identification of these individuals, all manifest left-handers, will be shown to have implications for diagnosis/remediation and for models of recovery of function.     

On the Bradley hypothesis concerning agrammatism: the nonword-interference effect

In 1980, D. C. Bradley, M. F. Garrett, and E. B. Zurif (in D. Caplan (Ed.), Biological studies of mental processes, Cambridge, MA: MIT Press) have proposed a lexical hypothesis on agrammatism. The theoretical background of this hypothesis is described. Then two experiments are reported with normal speakers on the so-called nonword-interference effect that has been one of the two major sources of experimental evidence for this hypothesis. The first experiment replicates the original finding that the interference effect is found when the nonword starts with a content word but not when it starts with a function word. In the second experiment, it is shown that this contrast is due to an artifact of the composition of the word list. When this list contains both content and function words, rather than only content words--as in Bradley's experiments and our Experiment I--both content and function nonwords show an equally sized interference effect. The consequences for the lexical hypothesis are discussed.     

Superimposition of response-independent reinforcement

Studies that have superimposed response-independent reinforcement (or reinforcers scheduled by contingencies placed on the absence of responding) upon conventional response-dependent schedules are reviewed. In general, providing alternative sources of reinforcement reduced response rates below the levels observed when alternative reinforcement was absent. However, response-rate elevation was sometimes found, particularly when rates of superimposed response-independent reinforcement were low. Superimposition of schedules providing reinforcers contingent on the absence of responding usually produced more severe response-rate decrements than superimposition of response-independent reinforcement. A variant of Herrnstein's equation, which assumes that some of the alternative reinforcers function as if they were delivered by baseline response-dependent source of reinforcement, is in qualitative agreement with the overall body of results obtained, and can predict both increases and decreases in response rate as resulting from superimposed reinforcers.     

Performance differences following exposure to predictable and unpredictable noncontingent outcomes in high and low achievers

Two experiments are described in which subjects rated as high or low in achievement motivation were exposed to uncontrollable outcomes on a cognitive task. Effects on subsequent performance on a different cognitive task were shown to depend on level of achievement motivation, on whether the uncontrollable outcomes were predictable or unpredictable, and on whether the uncontrollable outcomes were positive or negative. These findings have important theoretical implications which are discussed.     

An individualized regression and clustering assessment of the social values of adults and children

Research investigating social values in interdependency situations has generally demonstrated age differences across the 5- to 10-year-old age range. However, the precise nature of these differences is unclear. Further, the differences in the social values of adults and children has not been addressed. The present study examined the social values of undergraduates and children using a measurement technique designed to allow an accurate inference of social values. Ninety-one 6- to 10-year-old children and 100 undergraduates rated the desirability of a set of outcomes which systematically varied with regard to the benefits to themselves and another person. Theoretically specified characteristics of the outcomes were then used to generate a regression equation predicting the desirability ratings separately for each individual. These regression equations were then clustered into groups of individuals who used decision rules characteristic of the major social values. The results indicate that the 8- to 10-year-old children, compared to the 6- to 7-year olds, more often expressed a social value involving equality and tended to less often express a social value involving superiority. Comparison of the social values expressed by the children and adults indicated that the adults more often expressed group-enhancement and individualism social values and less often expressed a social value involving superiority.