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   662篇
  免费   47篇
  国内免费   1篇
  2024年   1篇
  2023年   13篇
  2022年   15篇
  2021年   19篇
  2020年   31篇
  2019年   43篇
  2018年   73篇
  2017年   45篇
  2016年   35篇
  2015年   22篇
  2014年   37篇
  2013年   70篇
  2012年   52篇
  2011年   56篇
  2010年   31篇
  2009年   17篇
  2008年   28篇
  2007年   31篇
  2006年   21篇
  2005年   12篇
  2004年   26篇
  2003年   7篇
  2002年   6篇
  2001年   2篇
  2000年   1篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1987年   1篇
  1983年   1篇
  1980年   1篇
排序方式: 共有710条查询结果,搜索用时 140 毫秒
591.
Age-related change in the difference between left- and right-side speed on motor examination may be an important indicator of maturation. Cortical maturation and myelination of the corpus callosum are considered to be related to increased bilateral skill and speed on timed motor tasks. We compared left minus right foot, hand, and finger speed differences using the Revised Physical and Neurological Assessment for Subtle Signs (PANESS; Denckla, 1985); examining 130 typically developing right-handed children (65 boys, 65 girls) ages 7-14. Timed tasks included right and left sets of 20 toe taps, 10 toe-heel alternation sequences, 20 hand pats, 10 hand pronate-supinate sets, 20 finger taps, and 5 sequences of each finger-to-thumb apposition. For each individual, six difference scores between left- and right-sided speeded performances of timed motor tasks were analyzed. Left-right differences decreased significantly with age on toe tapping, heel-toe alternations, hand pronation-supination, finger repetition, and finger sequencing. There were significant gender effects for heel-toe sequences (boys showing a greater left-right difference than girls), and a significant interaction between age and gender for hand pronation-supination, such that the magnitude of the left-right difference was similar for younger, compared with older girls, while the difference was significantly larger for younger, compared to older boys. Speed of performing right and left timed motor tasks equalizes with development; for some tasks, the equalization occurs earlier in girls than in boys.  相似文献   
592.
The present study examined the role that health‐related social control plays in promoting health‐enhancing behavioral reactions among married couples. Health‐related social control refers to interactions entailing influence and regulation of health practices. A sample of 109 couples answered questions about their social control interactions during structured phone interviews. Analyses maintaining the couple as the unit of analysis indicated that spouses' reports of more frequent social control overall and the use of positive, bilateral, and direct social control tactics predicted their partners' reports of health‐enhancing behavioral reactions.  相似文献   
593.
Animal analogue studies show that damaged adult brains reorganize to accommodate compromised functions. In the human arena, functional magnetic resonance imaging (fMRI) and other functional neuroimaging techniques have been used to study reorganization of language substrates in aphasia. The resulting controversy regarding whether the right or the left hemisphere supports language recovery and treatment progress must be reframed. A more appropriate question is when left-hemisphere mechanisms and when right-hemisphere mechanisms support recovery of language functions. Small lesions generally lead to good recoveries supported by left-hemisphere mechanisms. However, when too much language eloquent cortex is damaged, right-hemisphere structures may provide the better substrate for recovery of language. Some studies suggest that recovery is particularly supported by homologues of damaged left-hemisphere structures. Evidence also suggests that under some circumstances, activity in both the left and right hemispheres can interfere with recovery of function. Further research will be needed to address these issues. However, daunting methodological problems must be managed to maximize the yield of future fMRI research in aphasia, especially in the area of language production. In this review, we cover six challenges for imaging language functions in aphasia with fMRI, with an emphasis on language production: (1) selection of a baseline task, (2) structure of language production trials, (3) mitigation of motion-related artifacts, (4) the use of stimulus onset versus response onset in fMRI analyses, (5) use of trials with correct responses and errors in analyses, and (6) reliability and stability of fMRI images across sessions. However, this list of methodological challenges is not exhaustive. Once methodology is advanced, knowledge from conceptually driven fMRI studies can be used to develop theoretically driven, mechanism-based treatments that will result in more effective therapy and to identify the best patient candidates for specific treatments. While the promise of fMRI in the study of aphasia is great, there is much work to be done before this technique will be a useful clinical tool.  相似文献   
594.
Using a symbolic object such as a model as a source of information about something else requires some appreciation of the relation between the symbol and what it represents. Representational insight has been proposed as essential to success in a symbolic retrieval task in which children must use information from a hiding event in a scale model to find a toy hidden in a room. The two studies reported here examine and reject a proposed alternative account for success in the model task. The results with 2.5-year-olds and 3-year-olds show that children's successful use of a scale model cannot be attributed to the simple detection of the correspondences between the objects in the two spaces. A higher-level representation of the model-room relation (i.e. representational insight) is required. The results are discussed with respect to the coalescence of multiple factors in determining performance in the model task.  相似文献   
595.
Opfer JE  Bulloch MJ 《Cognition》2007,105(1):206-217
A number of recent models and experiments have suggested that evidence of early category-based induction is an artifact of perceptual cues provided by experimenters. We tested these accounts against the prediction that different relations (causal versus non-causal) determine the types of perceptual similarity by which children generalize. Young children were asked to label, to infer novel properties, and to project future appearances of a novel animal that varied in two opposite respects: (1) how much it looked like another animal whose name and properties were known, and (2) how much its parents looked like parents of another animal whose name and properties were known. When exemplar origins were known, children generalized to exemplars with similar origins rather than with similar appearances; when origins were unknown, children generalized to exemplars with similar appearances. Results indicate even young children possess the cognitive control to choose the similarities that best predict accurate generalizations.  相似文献   
596.
P300 amplitude predicts substance use or disorder by age 21. Earlier- versus later-onset substance disorders may reflect different levels of an externalizing psychopathology dimension. P300 in adolescence may not be as strongly related to later-onset substance problems as it is to earlier-onset ones. In the present study, visual P300 amplitude was measured at age 17 in a community-representative sample of young men. Substance and externalizing disorders were assessed at approximately ages 17, 20, and 24. Earlier-onset (by age 20) substance disorder was associated with higher rates of externalizing disorders than were later-onset problems. P300 amplitude was reduced in subjects with earlier-onset substance disorders, relative to later-onset and disorder-free subjects. Amplitude was also reduced in subjects with an externalizing disorder but no substance disorder. Earlier-onset subjects had reduced P300, even in the absence of an externalizing disorder. The results could not be attributed to a concurrent disorder or to recent substance use at the time of the P300 recording. The findings are consistent with P300 indexing an externalizing spectrum. Earlier-onset substance disorders are more strongly related to P300 and externalizing than are later-onset problems.  相似文献   
597.
Although experimental analysis methodologies have been useful for identifying the function of a wide variety of target behaviors (e.g., Iwata, Dorsey, Slifer, Bauman, & Richman, 1982/1994), only recently have such procedures been applied to verbal operants (Lerman et al., 2005). In the current study, we conducted a systematic replication of the methodology developed by Lerman et al. Participants were 4 children who had been diagnosed with developmental disabilities and who engaged in limited vocal behavior. The function of vocal behavior was assessed by exposing target vocal responses to experimental analyses. Results showed that experimental analyses were generally useful for identifying the functions of vocal behavior across all participants.  相似文献   
598.
This research examined gender-specific perceptions of risky sexual behavior norms among college students and their relationship with one’s own sexual behavior. We expected that students would misperceive the risky sexual behavior of their peers and that these perceptions would positively relate to their sexual behavior. Undergraduate students from the United States (N?=?687; 57.6% female) completed measures assessing perceived sexual behavior, sexual behavior, and other behaviors (e.g., marijuana use, alcohol consumption). Findings demonstrated that students perceived that others engaged in more risky sexual behavior than they do and that perceived norms were positively associated with one’s own behavior. The incorporation of personalized normative feedback regarding risky sexual behavior into brief interventions aimed at reducing risky sexual behavior is discussed.  相似文献   
599.
This study explored bullying in college by students and teachers. The reports of a sample of 1,025 undergraduates indicated that 24.7% had seen students bully other students occasionally and 2.8% very frequently, 5% had been bullied by students occasionally and 1.1% very frequently, 12.8% had seen teachers bully students occasionally and 1.9% very frequently, 4.2% had been bullied by teachers occasionally and .5% very frequently, while 3.2% had bullied other students occasionally and 1.9% very frequently. Male students bullied significantly more than females. Student bullying was predicted by having seen other students bully, and by having been bullied by both students and teachers.  相似文献   
600.
This article offers a reformulation of the negative reinforcement model of drug addiction and proposes that the escape and avoidance of negative affect is the prepotent motive for addictive drug use. The authors posit that negative affect is the motivational core of the withdrawal syndrome and argue that, through repeated cycles of drug use and withdrawal, addicted organisms learn to detect interoceptive cues of negative affect preconsciously. Thus, the motivational basis of much drug use is opaque and tends not to reflect cognitive control. When either stressors or abstinence causes negative affect to grow and enter consciousness, increasing negative affect biases information processing in ways that promote renewed drug administration. After explicating their model, the authors address previous critiques of negative reinforcement models in light of their reformulation and review predictions generated by their model.  相似文献   
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