A pharmacological examination of the resistance-to-change hypothesis of response strength.

The effects of d-amphetamine sulfate, sodium pentobarbital, haloperidol, and cholecystokinin-octapeptide were examined within the context of Nevin's (1974, 1979) resistance-to-change hypothesis of response strength. In three experiments, rats' responding was reinforced by delivery of food under chained random-interval 30-s random-interval 30-s, multiple fixed-interval 30-s fixed-interval 120-s, or multiple random-interval 30-s random-interval 120-s schedules. Each rat received several doses of each drug and changes in response rate were measured. The resistance-to-change hypothesis predicts greater disruption of response rate relative to baseline in the initial component of the chained schedule and in the 120-s component of the multiple schedules. In the chained schedule cholecystokinin-octapeptide produced greater reductions in response rate relative to baseline in the initial component. However, no differences between components were observed with haloperidol or sodium pentobarbital, and high doses of d-amphetamine reduced response rate in the terminal component relatively more than in the initial component. In the multiple schedules either no differences were observed between components or response rate was reduced more relative to baseline in the 30-s component. The data fail to support the notion that drugs may be viewed within the same context as other response disruptors such as extinction, satiation, and the presentation of alternative reinforcement.     

Does school desegregation change occupational goals of Negro males?

Instruments, designed to assess values which affect the motivation to work and aspiration levels, were administered to over 600 Negro male seniors in Texas high schools. Results indicate that the degree and duration of school desegregation these students have experienced, ranging from less than 1 to more than 5 years, have had little effect on work values and occupational aspirations.     

Conditioned reinforcement by conditional discriminative stimuli.

A concurrent-chains schedule was used to examine how a delay to conditional discriminative stimuli affects conditioned reinforcement strength. Pigeons' key-peck responses in the initial link produced either of two terminal links according to independent variable-interval 30-s schedules. Each terminal link involved an identical successive conditional discrimination and was segmented into three links: a delay interval (green), a color conditional discriminative stimulus (blue or red), and a line conditional discriminative stimulus (vertical or horizontal lines). Food delivery occurred 45 s after entering the terminal link with a probability of .5, but its conditional probability (1.0 or 0) depended on the combination of the color and the line stimuli. One of the color stimuli occurred independently of further responding, 5 s after entry into the right terminal link, but it occurred 35 s after entry into the left terminal link. One of the line stimuli occurred independently of responding 40 s after entry into either terminal link, synchronized with the offset of the color stimulus. The initial-link relative response rate for the right was consistently higher in comparison with a control condition in which the color stimuli occurred 20 s after entry into either terminal link. The preference for the short delay to the color conditional discriminative stimuli suggests the possibility of conditioned reinforcement by information about the relation between the line conditional discriminative stimuli and the outcomes.     

Choice and foraging: the effects of accessibility on acceptability.

Pigeons responded in a successive-encounters choice procedure in which accessibility of the less profitable of two outcomes varied either in terms of probability of encounter or search time to encounter (keeping search time to the more profitable outcome constant). When the less profitable outcome was made more probable its acceptance became more likely. However, when search time to encounter the less profitable outcome was shortened, its acceptance became less likely. Both results are consistent with the delay-reduction hypothesis and with an optimality model developed for application to the successive-encounters choice procedure.     

Recognition memory in hearing-impaired children: A levels-of-processing approach

Eighty-nine hearing-impaired children ranging in age from 6 years to 12 years, 11 months were given a recognition task comprised of items from the Raven Coloured Progressive Matrices and the Raven Learning Potential Test following administration of the Raven Coloured Progressive Matrices. The study was designed to determine whether recognition memory varied as a function of item type. The analysis indicated that performance on items involving analogous reasoning exceeded recognition for items requiring pattern completion through closure, which, in turn, exceeded performance for items involving simple pattern completion. Results are discussed in light of levels-of-processing.     

Which Is in Front of Chinese People,Past or Future? The Effect of Language and Culture on Temporal Gestures and Spatial Conceptions of Time

The temporal‐focus hypothesis claims that whether people conceptualize the past or the future as in front of them depends on their cultural attitudes toward time; such conceptualizations can be independent from the space–time metaphors expressed through language. In this paper, we study how Chinese people conceptualize time on the sagittal axis to find out the respective influences of language and culture on mental space–time mappings. An examination of Mandarin speakers' co‐speech gestures shows that some Chinese spontaneously perform past‐in‐front/future‐at‐back (besides future‐in‐front/past‐at‐back) gestures, especially when gestures are accompanying past‐in‐front/future‐at‐back space–time metaphors (Exp. 1). Using a temporal performance task, the study confirms that Chinese can conceptualize the future as behind and the past as in front of them, and that such space–time mappings are affected by the different expressions of Mandarin space–time metaphors (Exp. 2). Additionally, a survey on cultural attitudes toward time shows that Chinese tend to focus slightly more on the future than on the past (Exp. 3). Within the Chinese sample, we did not find evidence for the effect of participants' cultural temporal attitudes on space–time mappings, but a cross‐cultural comparison of space–time mappings between Chinese, Moroccans, and Spaniards provides strong support for the temporal‐focus hypothesis. Furthermore, the results of Exp. 2 are replicated even after controlling for factors such as cultural temporal attitudes and age (Exp. 3), which implies that linguistic sagittal temporal metaphors can indeed influence Mandarin speakers' space–time mappings. The findings not only contribute to a better understanding of Chinese people's sagittal temporal orientation, but also have additional implications for theories on the mental space–time mappings and the relationship between language and thought.     

风险取向类型与爱荷华赌博任务成绩的影响

神经科学领域的研究者们设计了测量情感决策的经典爱荷华赌博任务并提出了体细胞标记假说来解释其研究结果,但迄今为止这一假说还没有得到一致认可。许多研究提出了可能影响爱荷华赌博任务成绩的其他因素。本研究试图在前人研究的基础上采用实验法探讨风险取向类型这一人格因素是否影响正常个体的爱荷华赌博任务成绩。实验结果显示,不同风险取向类型的个体在爱荷华赌博任务中的成绩和表现截然不同。典型风险趋向型个体在爱荷华赌博任务中的表现类似于某些神经系统患者,倾向于更多地选择不利纸牌,其任务成绩显著差于典型风险回避型个体。这一研究结果表明：风险取向类型是影响正常个体爱荷华赌博任务成绩的重要因素之一。     

Hypothesis testing as risk behaviour with regard to beliefs

In this paper hypothesis‐testing behaviour is compared to risk‐taking behaviour. It is proposed that choosing a suitable test for a given hypothesis requires making a preposterior analysis of two aspects of such a test: the probability of obtaining supporting evidence and the evidential value of this evidence. This consideration resembles the one a gambler makes when choosing among bets, each having a probability of winning and an amount to be won. A confirmatory testing strategy can be defined within this framework as a strategy directed at maximizing either the probability or the value of a confirming outcome. Previous theories on testing behaviour have focused on the human tendency to maximize the probability of a confirming outcome. In this paper, two experiments are presented in which participants tend to maximize the confirming value of the test outcome. Motivational factors enhance this tendency dependent on the context of the testing situation. Both this result and the framework are discussed in relation to other studies in the field of testing behaviour. Copyright © 2000 John Wiley & Sons, Ltd.