首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2220篇
  免费   156篇
  国内免费   1篇
  2023年   10篇
  2022年   18篇
  2021年   30篇
  2020年   57篇
  2019年   73篇
  2018年   99篇
  2017年   104篇
  2016年   91篇
  2015年   67篇
  2014年   99篇
  2013年   312篇
  2012年   119篇
  2011年   146篇
  2010年   86篇
  2009年   81篇
  2008年   108篇
  2007年   103篇
  2006年   79篇
  2005年   81篇
  2004年   97篇
  2003年   73篇
  2002年   67篇
  2001年   27篇
  2000年   24篇
  1999年   28篇
  1998年   17篇
  1997年   18篇
  1996年   31篇
  1995年   22篇
  1994年   23篇
  1993年   15篇
  1992年   12篇
  1991年   10篇
  1990年   7篇
  1989年   10篇
  1988年   7篇
  1987年   8篇
  1986年   5篇
  1985年   8篇
  1984年   15篇
  1983年   5篇
  1982年   9篇
  1981年   7篇
  1980年   13篇
  1979年   9篇
  1978年   8篇
  1977年   5篇
  1975年   9篇
  1973年   5篇
  1971年   3篇
排序方式: 共有2377条查询结果,搜索用时 31 毫秒
841.
Two experiments explored the role of environmental cues in maintaining spatial orientation (sense of selflocation and direction) during locomotion. Of particular interest was the importance of geometric cues (provided by environmental surfaces) and featural cues (nongeometric properties provided by striped walls) in maintaining spatial orientation. Participants performed a spatial updating task within virtual environments containing geometric or featural cues that were ambiguous or unambiguous indicators of self-location and direction. Cue type (geometric or featural) did not affect performance, but the number and ambiguity of environmental cues did. Gender differences, interpreted as a proxy for individual differences in spatial ability and/or experience, highlight the interaction between cue quantity and ambiguity. When environmental cues were ambiguous, men stayed oriented with either one or two cues, whereas women stayed oriented only with two. When environmental cues were unambiguous, women stayed oriented with one cue.  相似文献   
842.
The fear conditioning paradigm is used to investigate the roles of various genes, neurotransmitters, and substrates in the formation of fear learning related to contextual and auditory cues. In the brain, nitric oxide (NO) produced by neuronal nitric oxide synthase (nNOS) functions as a retrograde neuronal messenger that facilitates synaptic plasticity, including the late phase of long-term potentiation (LTP) and formation of long-term memory (LTM). Evidence has implicated NO signaling in synaptic plasticity and LTM formation following fear conditioning, yet little is known about the role of the nNOS gene in fear learning. Using knockout (KO) mice with targeted mutation of the nNOS gene and their wild-type (WT) counterparts, the role of NO signaling in fear conditioning was investigated. Plasma levels of the stress hormone corticosterone were measured to determine the relationship between physiological and behavioral response to fear conditioning. Contextual fear learning was severely impaired in male and female nNOS KO mice compared with WT counterparts; cued fear learning was slightly impaired in nNOS KO mice. Sex-dependent differences in both contextual and cued fear learning were not observed in either genotype. Deficits in contextual fear learning in nNOS KO mice were partially overcome by multiple trainings. A relationship between increase in plasma corticosterone levels following footshock administration and the magnitude of contextual, but not cued freezing was also observed. Results suggest that the nNOS gene contributes more to optimal contextual fear learning than to cued fear learning, and therefore, inhibition of the nNOS enzyme may ameliorate context-dependent fear response.Anxiety disorders, such as post-traumatic stress disorder (PTSD), constitute the most prevalent mental illnesses in the United States, costing nearly one-third of the country''s total health bill (Greenberg et al. 1999). The treatment of these disorders requires overcoming complications such as reluctance to seek mental health treatment and an extremely high comorbidity rate with other affective disorders, reaching 80% (Brady 1997; Solomon and Davidson 1997). Emerging evidence suggests that dysfunctions underlying acquired anxiety and PTSD include an abnormal reaction to stress, which is mediated by specific neurochemical and neuroanatomical substrates (Yehuda and McFarlane 1995; Adamec 1997). Pharmacotherapies that target neuronal signaling molecules, such as nitric oxide (NO), may play a role in the treatment of these disorders.In the brain, N-methyl-d-aspartate receptor (NMDAR) activation and calcium influx into the cell activates the neuronal nitric oxide synthase (nNOS) enzyme to produce NO, which has the role of retrograde messenger (Snyder 1992). NO is involved in memory formation and synaptic plastic events such as late-phase long-term potentiation (LTP) (Lu et al. 1999; Arancio et al. 2001; Puzzo et al. 2006). Behavioral evidence in invertebrates (Lewin and Walters 1999; Muller 2000; Kemenes et al. 2002; Matsumoto et al. 2006) and vertebrates (Medina and Izquierdo 1995; Rickard et al. 1998; Ota et al. 2008) suggest that NO has a major role in consolidation of long-term memory (LTM). Recently, studies have shown that site-specific pharmacological blockade of NO signaling in rats impairs contextual (Resstel et al. 2008) and cued (Schafe et al. 2005) fear learning. However, the role of the nNOS gene in fear conditioning has not been investigated.In the present study, fear conditioning was investigated in homozygous nNOS knockout (KO) and wild-type (WT) mice. In the fear-conditioning paradigm, the association of a footshock (unconditioned stimulus; US), with a specific context and a neutral stimulus (auditory cue) results in learned fear. Re-exposure to the conditioning context and to the previously neutral auditory cue (conditioned stimulus; CS) elicits a freezing response in the absence of the aversive US. Thus, the fear-conditioning paradigm includes both contextual and cued fear learning components, which can be measured in separate tests. Fear conditioning recruits both the amygdala (emotional cue learning) and the hippocampus (spatial/contextual learning) (Phillips and LeDoux 1992; Goosens and Maren 2004; Mei et al. 2005). The involvement of these brain regions in fear learning and anxiety has been confirmed by animal and human imaging studies (LeDoux 1998; Rauch et al. 2006).We report that nNOS KO mice showed a severe deficiency in contextual fear learning and a less marked deficit in cued fear learning compared with WT mice after a single fear-conditioning session. This deficiency was partially improved by multiple (four) fear-conditioning sessions. In addition, we observed that plasma levels of corticosterone, the primary stress hormone in rodents, are related to contextual fear learning ability.  相似文献   
843.
In two experiments, while event-related potentials (ERPs) were recorded, participants named picture targets that were preceded by masked word primes that corresponded either to the name of the picture target or to an unrelated picture name. Experiment 1 showed significant priming effects in the ERP waveforms, free from articulator artifact, starting as early as 200 msec post target onset. Possible loci of these priming effects were proposed within the framework of generic interactive activation models of word recognition and picture naming. These were grouped into three main components: object-specific structural representations, amodal semantic representations, and word-specific phonological and articulatory representations. Experiment 2 provided an initial test of the possible role of each of these components by comparing within-language repetition priming with priming from translation equivalents in bilingual participants. The early and widespread effects of noncognate translation primes in L1 on picture naming in L2 point to object-specific and amodal semantic representations as the principal loci of priming effects obtained with masked word primes and picture targets.  相似文献   
844.
The psychometric properties of the systemizing quotient (SQ) developed by Baron‐Cohen (2003) are investigated in three studies. Furthermore, we examine the notion that the ability to systemize should be independent of intelligence. In Studies 1 and 2, confirmatory factor analyses are used to examine the factor structure of the SQ. Study 3 examines the relationship between systemizing, mental rotation and intelligence. Studies 1 and 2 indicate that the SQ does not possess a unifactorial structure but is best considered as four related factors; Study 3 found that SQ was not related to intelligence, although mental rotation was. A four factor structure using fewer items was a better fit for the data than either the original version of the SQ or Wakabayashi et al.'s (2006) revised version. Overall these results support Baron‐Cohen's view that SQ is not related to intelligence. Although mental rotation is correlated to SQ, it is not the main determinant of SQ. The problems of self‐report measures are discussed along with the difficulties related to measuring systemizing.  相似文献   
845.
846.
A central claim of the religious economies model is that religious competition affects levels of religious participation and commitment primarily because religious competition pushes the suppliers of religion (religious leaders and organizations) to market their faith more vigorously and effectively. We examine whether U.S. congregations experiencing greater religious competition measured by their smaller religious market share do more to recruit new members, offer more services to current followers, and whether their clergy work longer hours. The efforts of congregations and clergy do vary substantially, but this variation is not related to their denomination's market share. The variations are also not due to religious pluralism, intradenominational competition, or evangelical market share. Members of small market share congregations are more committed, but this higher commitment does not appear to arise because religious suppliers are responding to religious competition. Several alternative explanations for the higher commitment levels of small market share groups are offered with a discussion of the implications for theories of religious competition.  相似文献   
847.
In this study, we investigate whether language and music share cognitive resources for structural processing. We report an experiment that used sung materials and manipulated linguistic complexity (subject-extracted relative clauses, object-extracted relative clauses) and musical complexity (in-key critical note, out-of-key critical note, auditory anomaly on the critical note involving a loudness increase). The auditory-anomaly manipulation was included in order to test whether the difference between in-key and out-of-key conditions might be due to any salient, unexpected acoustic event. The critical dependent measure involved comprehension accuracies to questions about the propositional content of the sentences asked at the end of each trial. The results revealed an interaction between linguistic and musical complexity such that the difference between the subject- and object-extracted relative clause conditions was larger in the out-of-key condition than in the in-key and auditory-anomaly conditions. These results provide evidence for an overlap in structural processing between language and music.  相似文献   
848.
Newell, Mitchell, and Hayes (NMH) conduct three experiments designed to test whether exemplar cuing (EC) theory or a statistical format theory provides a more accurate account for how people make judgments about low‐probability events. They report finding support for the statistical format theory and little or no support for EC. However, NMH misstate the requirements for the production of exemplars in EC theory. As a result, they confuse non‐exemplar conditions with exemplar conditions in their experiments, and find results that are virtually irrelevant to EC theory. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
849.
ABSTRACT— This article presents the first meta-analysis of experimental research on rejection, sampling 88 studies. The results are consistent with a needs account, which states that rejection frustrates basic psychological needs, but not with a numbness account, which states that rejection causes physical and emotional numbness. Rejection moderately lowers mood ( d =−0.50) and self-esteem ( d =−0.70), but does not decrease arousal or flatten affect. Both belonging ( d = 0.69) and control ( d = 1.16) are frustrated by rejection. Aggressive responses to rejection, considered paradoxical by some, appear to be due to attempts to gain control; measures that contrast belonging and control ( d =−1.17) cause antisocial responding, whereas measures that do not allow for control to be restored cause prosocial responding ( d = 1.21). These findings suggest that rejection makes individuals feel bad—ready to act to restore control or belonging—and that they will prioritize restoring control even if it requires being antisocial.  相似文献   
850.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号