Asymptotic free-operant discrimination reversal in the goldfish.

Studied 8 goldfish in a 7-stage experiment. The general pattern of asymptotic free-operant red-green discrimination reversal was the same whether the schedule of reinforcement for response to S+ was VI 1 min. or VI 2 min., whether 1 or 3 days of training per reversal were given, whether reversal occurred at the start of an experimental session or in midsession, and whether 1 or 2 stimuli were encountered in each session. Rate of response to S+ increased gradually from a low initial level, decreasing slightly in the intersession interval, while rate of response to S- decreased gradually from a high initial level, increasing slightly in the intersession interval. The pattern was also the same as that found in discrete-trial experiments with goldfish but different from that found both in free-operant and discrete-trial experiments with pigeons. Data are reported for control Ss treated like the experimental Ss in all respects except for the correlation between color and reinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Criterion shifts in recall.

Examined criterion shifts in recall in light of clarifications of the distinction between Type I and Type II signal detection analyses and of the concept of criterion. With a new index of the criterion, B. B. Murdock's evidence for criterion shifts in recall is found to be evidence that Ss hold their criteria constant across different retention intervals. However, with the new criterion index, criterion shifts are found in intelligibility experiments and in the short-term recall experiment by E. L. Bjork and A. F. Healy. In these studies, Ss' criteria became more lax with increasing task difficulty. A possible strategy used by the Ss is proposed to explain this finding as well as the finding that the Ss shift their criteria in Bjork and Healy's task but not in Murdock's. Finally, this analysis is applied to recall studies in which the S is allowed to leave blanks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On paradigm shifts.

Three points of issue raised by E. M. Segal and R. Lachman's (see record 1972-22033-001) article on paradigm shifts in psychology are discussed: (1) that scientists are more concerned with a paradigm than a world view, (2) the criteria for identifying scientific revolution, and (3) the demise of stimulus-response behaviorism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative two-process analysis of avoidance conditioning in goldfish.

The shuttlebox performance of goldfish was studied under standardized conditions in a variety of problems: with or without an avoidance contingency, a CS-termination contingency, and an escape contingency. The effects of CS-only, unconditioned stimulus/stimuli (UCS)-only, and explicitly unpaired training were also examined. All data could be simulated quantitatively with a version of O. H. Mowrer's (1947) 2-process theory expressed in 2 learning equations (one classical, the other instrumental) and a performance equation. The good fit suggests that the theory is worth developing further with new experiments designed to challenge it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing narrative time shifts.

This study examined how the chronological distance between 2 consecutively narrated story events affects the on-line comprehension and mental representation of these events. College students read short narrative passages from a computer screen and responded to recognition probes. The results of 4 experiments consistently demonstrated that readers used temporal information to construct situation models while comprehending narratives. First, sentence reading times increased when there was a narrative time shift (e.g., as denoted by an hour later) as opposed to when there was no narrative time shift (e.g., as denoted by a moment later). Second, information from the previously narrated event was less accessible when it was followed by a time shift than when it was not. Third, 2 events that were separated by a narrative time shift were less strongly connected in long-term memory than 2 events that were not separated by a narrative time shift. The results suggest that readers use a strong iconicity assumption during story comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination reversal in the goldfish as a function of training conditions.

Performed 3 experiments on goldfish (n = 11, 24, and 10, respectively) and found that Ss showed progressive improvement in red-green discrimination reversal under a variety of training conditions, the amount of improvement varying with conditions. Exposing the animals to S+ during reinforcement had the greatest facilitating effect on performance of the several modifications introduced. The use of a center key, response to which was required for presentation of the discriminanda, also produced substantial facilitation. However, feeding Ss at the locus of response was of relatively minor importance, and increasing the duration of unreinforced exposure to S- had no effect. Some questions about the relation between improvement in goldfish and improvement in more advanced animals are considered. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expectancy shifts and the expectancy confidence hypothesis.

Explanations of differences in the size of expectancy changes following task outcomes are considered. The control perception hypothesis, the most frequently proposed explanation, is that small expectancy shifts occur when task outcomes are perceived to be externally (i.e., chance) controlled. An alternative explanation, the expectancy confidence hypothesis, is that small shifts occur when Ss are relatively confident of the accuracy of their expectations. Two experiments with 120 female undergraduates examined these positions. Exp I partially replicated the study of J. B. Rotter et al (1961), often cited as supporting the control perception hypothesis. Expectancy confidence was assessed, and as predicted by the expectancy confidence hypothesis, expectancy shifts were related negatively to expectancy confidence. Skill perceptions and levels of expectancy confidence were maniplated in Exp II, and their impact was assessed by several expectancy shift measures. Expectancy confidence influenced expectancy shifts as predicted for 4 of 5 measures, whereas skill perceptions did not significantly affect expectancy shifts on any measure. Expectancy confidence thus exerts a substantial impact on expectancy shifts. The relevance of the findings for a 3rd explanation of expectancy shifts, the causal stability hypothesis, is discussed. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hair cell heterogeneity in the goldfish saccule

A set of cytological studies performed in the utricle and saccule of Astronotus ocellatus (Teleostei, Percomorphi, Cichlidae) identified two basic types of hair cells and others with some intermediate characteristics. This paper reports on applying the same techniques to the saccule of Carassius auratus (Teleostei, Otophysi, Cyprinidae) and demonstrates similar types of hair cells to those found in Astronotus. Since Carassius and Astronotus are species of extreme taxonomic distance within the Euteleostei, two classes of mechanoreceptive hair cells are likely to represent the primitive condition for sensory receptors in the euteleost inner ear and perhaps in all bony fish ears.     

Incentive downshifts evoke search repertoires in rats.

Negative incentive contrast effects (NCEs) have typically been attributed to frustration or the decremental generalization of learned associations. The purpose of these experiments was to clarify the relation of NCEs to the repertoires of functional search behaviors evoked by incentive downshifts. Rats shifted from 32% to 4% sucrose-solution decreased consummatory responses but increased nose-down locomotion, orientation, location entries, and sampling of alternatives relative to unshifted controls. These changes in behavior were terminated or failed to occur under incentive upshifts. Furthermore, reward downshifts did not produce avoidance of the location of the shifted incentive. Increased search occurred whether or not alternative reward locations were available. Together the evidence suggests that NCEs are related to evoked search modes supporting a repertoire of functional behaviors related to finding food. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intradimensional and extradimensional shifts in spatial learning.

Animals trained on 2 discriminations learn the 2nd rapidly if the relevant stimuli are from the same dimension as the 1st (an intradimensional or ID shift) but slowly if the relevant stimuli for the 2 problems are from different dimensions (an extradimensional or ED shift). Four experiments examined ID and ED shifts in spatial learning. Rats trained on 2 spatial problems learned the 2nd more rapidly than rats whose 1st problem had been nonspatial. But this difference between ID and ED shifts depended on the spatial relationship between rewarded (S+) and unrewarded (S-) alternatives in the 2 spatial problems. The results imply that rats trained on a spatial discrimination do not learn to attend to all spatial landmarks but only to those that serve to differentiate S+ and S-. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of social comparison in choice shifts.

Tested social comparison predictions regarding influence processes related to risk taking in groups. It was predicted that a more complete information exchange condition would produce a shift toward risk of greater magnitude than a traditional information exchange condition. Two replications using 137 college students confirmed the prediction. Shifts toward risk were as likely to occur in groups where Ss exchanged information about their positions on the Choice Dilemma Questionnaire (CDQ) and information about their self-ratings of ability as in ordinary group discussions of the CDQ items. Ss in groups where only information about CDQ positions was exchanged showed far fewer shifts to risk. Findings are discussed in terms of a social comparison analysis of the social influence processes involved in risky shifts, which assumes that comparison processes can be engaged fully only when comparability is established by knowledge of other group members' standing on traits thought to be related to risk taking. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interocular transfer of visual discriminations in goldfish after selective commissure lesions.

Goldfish with transections of the intertectal commissure learned but failed to transfer interocularly a simple visually cued avoidance task in a shuttle box, whereas posterior commissure lesions had no effect on this simple transfer task. However, Ss with tectal commissure lesions showed normal interocular transfer of a shape discrimination, once discrimination pretraining with color cues had been carried out with each eye separately. Lesions of anterior commissure had no effect on either shape or color transfer, but Ss with intended cuts of the postoptic commissures showed striking deficits of interocular transfer. As with comparable studies in the pigeon, it is concluded that postoptic, but not tectal, commissures are required for interocular transfer in the goldfish. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociation of place and cue learning by telencephalic ablation in goldfish.

This study examined the spatial strategies used by goldfish (Carassius auratus) to find a goal in a 4-arm maze and the involvement of the telencephalon in this spatial learning. Intact and telencephalon-ablated goldfish were trained to find food in an arm placed in a constant room location and signaled by a local visual cue (mixed place-cue procedure). Both groups learned the task, but they used different learning strategies. Telencephalon-ablated goldfish learned the task more quickly and made fewer errors to criterion than controls. Probe trials revealed that intact goldfish could use either a place or a cue strategy, whereas telencephalon-ablated goldfish learned only a cue strategy. The results offer additional evidence that place and cue learning in fish are subserved by different neural substrates and that the telencephalon of the teleost fish, or some unspecified structure within it, is important for spatial learning and memory in a manner similar to the hippocampus of mammals and birds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incentive magnitude, learning, and performance in animals.

The results of studies concerned with the effects of magnitude of incentive on a variety of dependent variables are highly consistent. Though there is a need for further research there presently exists sufficiently well ordered data to permit meaningful theorizing. 87 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incentive program decreases no-shows in nontreatment substance abuse research.

This study examined the use of a low-cost incentive program to decrease the rate of unanticipated no-shows in a nontreatment study of the genetics of substance dependence. Low-cost retail items (such as calling cards or gift certificates) were offered contingent on attendance at the first scheduled research appointment. Although the intervention did not result in an increase in the rate of attendance at appointments, it reduced the likelihood of unanticipated no-shows by almost 50%. This reduction was accompanied by a significant increase in advance cancellations. Despite limitations due to the study's A-B design, this research demonstrates that it may be possible to use modest incentives to increase the efficiency of research enrollment and increase service provision for substance abusers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Abstinence Incentive Effects in a Short-Term Outpatient Detoxification Program.

Despite being widely available, outpatient detoxification has limited efficacy as a stand-alone treatment. This study examined whether abstinence-contingent incentives would improve outcomes for patients entering outpatient opiate detoxification. Participants (N = 211) received a $100 voucher on the last day of detoxification either contingent on opiate and cocaine abstinence or noncontingently. Urine samples were collected at intake, on Wednesday, Friday (the last day of detoxification), and the following Monday. Among contingent-voucher participants, 31% were drug-free on Friday compared with 18% of noncontingent controls (Z = 2.4, p     

浅谈企业激励机制

人力资源成为企业发展的重要手段.阐明了激励机制在吸引人才、创造企业良性竞争环境、开发员工潜能方面的作用,探索了正确实施激励机制的基础要从满足人的需求出发.分析了企业在运用激励机制方面存在的激励就是奖励、激励过程中缺乏沟通、绩效考核缺少客观的评价标准等问题.提出了营造有归属感的企业文化、特岗特薪制、股权激励等运用激励机制的建议.     

Sustained potential shifts in the toad tectum reflect prey-catching and avoidance behavior.

Sustained potential shifts (SPS) were recorded for 10 sec from the surface of the optic tectum of toads presented with live prey and moving artificial prey stimuli. On the anterior tectal surface, a negative SPS was followed by a positive wave; the converse was true for the posterior tectum. Some animals were immobilized, and they exhibited a monophasic negative SPS in the anterior tectum and a positive wave in more posterior regions. The number of orienting responses made by toads to moving "wormlike" stimuli was reflected in the amplitude of the SPS, as was avoidance to stimuli in an "antiworm" configuration. Behavioral activity was most closely related to the negativity of the SPS recording. The SPS of toads responding to live prey showed no direct time relationship between the SPS and behavior, suggesting that the SPS reflects sensory or decision-making activity rather than the consequent behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical learning induces discrete shifts in the allocation of working memory resources.

Observers can voluntarily select which items are encoded into working memory, and the efficiency of this process strongly predicts memory capacity. Nevertheless, the present work suggests that voluntary intentions do not exclusively determine what is encoded into this online workspace. Observers indicated whether any items from a briefly stored sample display had changed. Unbeknown to observers, these changes were most likely to occur in a specific quadrant of the display (the dominant quadrant). Across 84 subjects and 5 groups of observers, change detection accuracy was significantly higher for items in the dominant quadrant, suggesting that memory encoding was biased towards the dominant quadrant. Only 9 of the 84 subjects were able to correctly specify the dominant quadrant when asked whether any location was more likely to contain the changed item, but more sensitive forced-choice procedures did reveal above-chance discrimination of the dominant quadrant. Nevertheless, because forced choice performance was unrelated to the size of the bias and no observer reported a biased encoding strategy, the bias was unlikely to depend on voluntary encoding strategies. The encoding bias was not due to a reduction in the response threshold for indicating changes in the dominant quadrant (Experiment 2). Finally, separate measures of the number and resolution of the representations in memory suggested that encoding was biased in a discrete slot-based fashion (Experiment 3). That is, although items in the dominant quadrant were more likely to be encoded into memory, mnemonic resolution for the favored items was not affected. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decision processes in recognition memory: Criterion shifts and the list-strength paradigm.

This article focuses on decision processes in recognition memory. It begins with investigation of the hypothesis that the measured criterion increases systematically with the memorability of old items. Three experiments using the list-strength paradigm, and a review of the prior literature, present results consistent with this hypothesis. Several psychological models of criterion placement are examined, generating different predictions about the relative sizes of criterion shifts for strong and weak items. A range model, in which criterion placement depends on the estimated range of the old and new distributions, predicts that criterion shifts should be larger for weak items; this result emerges in a reanalysis of prior studies. The general discussion elaborates on how a focus on criterion placement can explain the mirror effect (Glanzer, Adams, Iverson, & Kim, see record 1993-40158-001) and provides a framework for testing Shiffrin, Ratcliff, and Clark's (see record 1990-13917-001) claims about why null effects of list strength occur with repetition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)