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721.
A generalization of Ehrenfest's urn model is suggested. This will allow usto treat a wide class of stochastic processes describing the changes ofmicroscopic objects. These processes are homogeneous Markov chains. Thegeneralization proposed is presented as an abstract conditional (relative)probability theory. The probability axioms of such a theory and some simpleadditional conditions, yield both transition probabilities and equilibriumdistributions. The resulting theory interpreted in terms of particles andsingle-particle states, leads to the usual formulae of quantum and classicalstatistical mechanics; in terms of chromosomes and allelic types, it allowsthe deduction of many genetical models including the Ewens sampling formula;in terms of agents' strategies, it gives a justification of the ``herdbehaviour' typical of a population of heterogeneous economic agents. 相似文献
722.
Corina U. Greven Nicole Harlaar Yulia Kovas Tomas Chamorro-Premuzic Robert Plomin 《Psychological science》2009,20(6):753-762
ABSTRACT— Evidence suggests that children's self-perceptions of their abilities predict their school achievement even after one accounts for their tested cognitive ability (IQ). However, the roles of nature and nurture in the association between school achievement and self-perceived abilities (SPAs), independent of IQ, is unknown. Here we reveal that there are substantial genetic influences on SPAs and that there is genetic covariance between SPAs and achievement independent of IQ. Although it has been assumed that the origins of SPAs are environmental, this first genetic analysis of SPAs yielded a heritability of 51% in a sample of 3,785 pairs of twins, whereas shared environment accounted for only 2% of the variance in SPAs. Moreover, multivariate genetic analyses indicated that SPAs predict school achievement independently of IQ for genetic rather than environmental reasons. It should therefore be possible to identify "SPA genes" that predict school achievement independently of "IQ genes." 相似文献
723.
Smith CU 《Brain and cognition》2009,71(2):54-63
This is the second part of a review of the work of quantum physicists on the 'hard part' of the problem of mind. After an introduction which sets the scene and a brief review of contemporary work on the neural correlates of consciousness (NCC) the work of four prominent modern investigators is examined: J.C. Eccles/Friedrich Beck; Henry Stapp; Stuart Hameroff/Roger Penrose; David Bohm. With the exception of David Bohm, all attempt to show where in the brain's microstructure quantum affects could make themselves felt. It is reluctantly concluded that none have neurobiological plausibility. They are all instances, to paraphrase T.H. Huxley, of a beautiful hypothesis destroyed by ugly facts. David Bohm does not attempt to fit his new quantum physics to contemporary neurobiology but instead asks for a radical rethink of our conventional scientific paradigm. He suggests that we should look towards developing a 'pan-experientialism' or 'dual-aspect monism' where consciousness goes 'all the way down' and that the 'hard problem' is not soluble within the framework of ideas provided by 'classical' natural science. 相似文献
724.
We present a psychometric scale that assesses risk taking in five content domains: financial decisions (separately for investing versus gambling), health/safety, recreational, ethical, and social decisions. Respondents rate the likelihood that they would engage in domain‐specific risky activities (Part I). An optional Part II assesses respondents' perceptions of the magnitude of the risks and expected benefits of the activities judged in Part I. The scale's construct validity and consistency is evaluated for a sample of American undergraduate students. As expected, respondents' degree of risk taking was highly domain‐specific, i.e. not consistently risk‐averse or consistently risk‐seeking across all content domains. Women appeared to be more risk‐averse in all domains except social risk. A regression of risk taking (likelihood of engaging in the risky activity) on expected benefits and perceived risks suggests that gender and content domain differences in apparent risk taking are associated with differences in the perception of the activities' benefits and risk, rather than with differences in attitude towards perceived risk. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
725.
726.
The protein synthesis-dependent form of hippocampal long-term potentiation (late-LTP) is thought to underlie memory. Its induction requires a distinct stimulation strength, and the common opinion is that only repeated tetani result in late-LTP whereas as single tetanus only reveals a transient early-LTP. Properties of LTP induction were compared to learning processes where repetition is often the prerequisite for a long-lasting memory. However, also single events can lead to manifested memory. If LTP subserves processes of learning, similar results should be detectable for LTP. Here we show that a single tetanus is sufficient to induce late-LTP requiring dopaminergic co-transmission during induction. 相似文献
727.
728.
Adam M. Briggs Claudia L. Dozier Amber N. Lessor Bertilde U. Kamana Rachel L. Jess 《Journal of applied behavior analysis》2019,52(4):956-973
Previous research indicates that manipulating dimensions of reinforcement during differential reinforcement of alternative behavior (DRA) for situations in which extinction cannot be implemented is a potential approach for treating destructive behavior. Therefore, we replicated and extended previous research by determining (a) the conditions under which DRA without extinction decreased and maintained low levels of destructive behavior and (b) whether intervention effects maintained during reinforcement schedule thinning for the alternative response (i.e., compliance). Results showed that effective treatments were developed in the absence of extinction by manipulating the quality of reinforcement for compliance for 2 participants and by combining manipulations of the magnitude and quality of reinforcement for compliance for the other 2 participants. However, maintaining treatment effects during reinforcement schedule thinning required combining the magnitude and quality of reinforcement for 3 of the 4 participants. We discuss the clinical utility of this approach, review limitations of the study, and suggest directions for future research. 相似文献
729.
People rely on support from others to accomplish mundane and momentous tasks. When asking for assistance, is it beneficial to incentivize a helper by offering a motivated gift (i.e., a gift with the hope of getting support in return)? Six studies (N > 2,500) examine the frequency and potential costs of motivated gifts. In Study 1, a third of Americans indicated that they had given a motivated gift at least once, while nearly two‐thirds believed they had received one. In Studies 2a–d, most participants who imagined receiving a motivated gift before a favor request reported lower willingness to help and anticipated satisfaction from helping than participants who imagined simply being asked for a favor. Finally, Study 3 replicates these findings with actual help provided among friends in a laboratory setting. Findings suggest that motivated gifts are relatively common but may sometimes undermine the assistance that people hope to receive. 相似文献
730.
Arden U. Gale Rochelle C. Moss Kristin K. Higgins 《Journal of counseling and development : JCD》2007,85(2):204-210
The authors review previous examinations of the American Counseling Association's (ACA) Journal of Counseling & Development (JCD), consider various editors' policies that shaped the Journal, and update L. W. Harmon and H. E. Harker's (1989) analysis of special interest topics featured in JCD. Studying the flagship professional journal of ACA provides insight into the evolution and development of the profession of counseling. 相似文献