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291.
Before 12 months of age, infants have difficulties coordinating and sequencing their movements to retrieve an object concealed in a box. This study examined (a) whether young infants can discover effective retrieval solutions and consolidate movement coordination earlier if exposed regularly to such a task and (b) whether different environments, indexed by box transparency, would impact the rate of learning and time of discovery of these solutions. Infants (N=12) were presented with an object retrieval task every week from 6 1/2 months of age until they were able to retrieve the toy from the box using coordinated two-handed patterns for 3 weeks. To reach that criterion, infants tested with an opaque box took 2 1/2 months and infants tested with a semitransparent box took 1 1/2 months. Both groups outperformed age-matched controls who received a one-time exposure to the task. Repeated exposure to the task and vision of the toy significantly enhanced this process of solution discovery.  相似文献   
292.
This study examined 3-year-olds' explanations for actions of theirs that were premised on a false belief. In Experiment 1, children stated what they thought was inside a crayon box. After stating "crayons," they went to retrieve some paper to draw on. Children were then shown that the box contained candles and were asked to (a) state their initial belief and (b) explain their action of getting paper. Children who were unable to retrieve their false belief were unable to correctly explain their action. Experiments 2 and 3 ruled out several alternative interpretations for these findings. In Experiment 4, children planned and acted on their false belief. Again, children who were unable to retrieve their false belief were unable to correctly explain their action.  相似文献   
293.
Recent evidence suggests a close functional relationship between memory formation in the hippocampus and dopaminergic neuromodulation originating in the ventral tegmental area and medial substantia nigra of the midbrain. Here we report midbrain activation in two functional MRI studies of visual memory in healthy young adults. In the first study, participants distinguished between familiar and novel configurations of pairs of items which had been studied together by either learning the location or the identity of the items. In the second study, participants studied words by either rating the words' pleasantness or counting syllables. The ventral tegmental area and medial substantia nigra showed increased activation by associative novelty (first study) and subsequent free recall performance (second study). In both studies, this activation accompanied hippocampal activation, but was unaffected by the study task. Thus midbrain regions seem to participate selectively in hippocampus-dependent processes of associative novelty and explicit memory formation, but appear to be unaffected by other task-relevant aspects.  相似文献   
294.
Octopus macropus and Octopus vulgaris have overlapping habitats and are exposed to similar temporal changes. Whereas the former species is described as nocturnal in the field, there are conflicting reports about the activity time of the latter one. To compare activity patterns, the authors tested both species in the laboratory. Octopuses were exposed to a light-dark cycle and held under constant dim light for 7 days each. O. macropus showed nocturnal and light-cued activity. According to casual observations, O. vulgaris started out nocturnal but had switched to mostly diurnal when the experiment began. Individual variation of its activity was found. The different activity patterns of O. macropus and O. vulgaris might reflect their lifestyles, the latter species being more generalist.  相似文献   
295.
Male Wistar rats were exposed to one-trial step-down inhibitory avoidance training using a 0.5 mA footshock. Through bilaterally implanted indwelling cannulae, they received bilateral 0.5 microL infusions of saline, mecamylamine (1.0 or 10.0 microg/side), or nicotine (0.6 or 3.0 microg/side) into the basolateral complex of the amygdaloid nucleus (BLA). Infusions were either 10 min before training (Experiment 1) or 4 min after training (Experiment 2). In Experiment 1, the animals were tested three times: first for working memory (WM) 5 s after training, then for short-term memory (STM) 90 min later, and finally for long-term memory (LTM) 24 h later. Mecamylamine depressed and nicotine enhanced WM, STM, and LTM. In Experiment 2, the treatments were given after WM was presumably over. Again, mecamylamine inhibited and nicotine enhanced STM and LTM. The results indicate that nAChRs in BLA participate in the regulation of WM formation and STM and LTM acquisition and consolidation.  相似文献   
296.
In a recent paper, Chee et al. report differences in the patterns of brain activation and deactivation in bilinguals with different levels of proficiency in their second language. Most intriguingly, this research addressed the issue of the neural basis of phonological working memory (PWM), which is crucial in language acquisition, in subjects who were under comparable social pressure to be bilinguals. The results led the authors to suggest that a more readily available working memory system might correlate with the attainment of superior proficiency in a second language.  相似文献   
297.
We examined the incidence, characteristics, and predictors of separations of children from mothers in 543 poor families receiving public assistance, 251 of whom had experienced homelessness during the previous 5 years. Forty-four percent of the homeless mothers and 8% of housed mothers were separated from one or more children. A total of 249 children were separated from 110 homeless families and 34 children from 23 housed families. Children were placed with relatives and in foster care but were rarely returned to their mothers. Maternal drug dependence, domestic violence, and institutionalization predicted separations, but homelessness was the most important predictor, equivalent in size to 1.9 other risk factors. We infer that policies regarding child welfare and substance abuse treatment should be changed to reduce unnecessary placements. Studies of homeless children who remain with families may be biased if separated children are excluded.  相似文献   
298.
Couples' experiences of daily stress can be detrimental for partners' individual and relational well-being, specifically their identity as a couple, their relational satisfaction, and their life satisfaction. Grounded in the Systemic Transactional Model, this study aimed at analyzing factors that may safeguard partners and their relationship from detrimental effects of internal stress (i.e., stress that originates inside the relationship). We examined the buffering effect of partners' positive dyadic coping and internal problem resolution. Daily diary data were collected across 7 days from 82 heterosexual couples. Multilevel dyadic analyses showed that internal stress was negatively associated with partners' individual and relational well-being. Positive dyadic coping moderated the association between partners' internal stress and couple satisfaction for both partners, but not life satisfaction and couple identity. Moreover, for partners who reported a resolution to the internal problem, the negative associations of internal stress with life satisfaction, couple satisfaction, and couple identity were significantly lower than for those who did not resolve the internal problem. This study confirms the negative role of internal stress on well-being, shows the associations between internal stress and couple identity, and highlights the protective role of dyadic coping and internal problem resolution in couples' daily lives.  相似文献   
299.
In this article we propose looking into some factors for Civic Participation and the intention to continue to participate among local (Study I) and immigrant (Study II) young people living in Belgium and Germany. In Study I, 1,079 young people (Mage = 19.23, 44.9% males) completed a self-report questionnaire asking about their Civic Participation. Multiple linear regressions reveal (a) evidence of a pool of variables significantly linked to Civic Participation: Institutional Trust, Collective-Efficacy, Parents’ and Peers’ Support, Political Interest, Motivations and (b) that Civic Participation, along with the mediation of the Participation's Efficacy, explains the Intention to Continue to Participate. An explanatory model was constructed on participation and the Intention to Continue to Participate on behalf of the native youth. This model is invariant between the two countries. In Study II, 276 young Turkish immigrants (Mage = 20.80, 49.3% males) recruited in Belgium and Germany filled out the same questionnaire as in Study I. The same analysis was conducted as for Study I, and they provided the same results as the native group, highlighting the invariance of the model between natives and immigrants. Applicative repercussions are discussed.  相似文献   
300.
Transracial adoptees represent a specific group of immigrants who experience unique immigration processes that bring them face‐to‐face with two cultural backgrounds: that of their heritage culture on one hand and that of their national culture on the other hand. However, there is a scarcity of studies focused on the way these processes unfold within adoptive families. This study was aimed at exploring how transracial adoptees cope with the construction of their ethnic identity. Administering a self‐report questionnaire to 127 transracial adoptees and their mothers, for a total of 254 participants, we first investigated the association between mothers' cultural socialisation (enculturation and preparation for bias strategies) and adoptees' ethnic identity (i.e. ethnic identity exploration and ethnic identity affirmation dimensions). We then investigated whether ethnic identity affects self‐esteem by testing the hypothesis that national identity moderates the relationship between ethnic identity and self‐esteem. Results revealed that mothers' enculturation (but not their preparation for bias) supported adoptees' ethnic identity exploration, which in turn was positively associated with ethnic identity affirmation. Moreover, we confirmed the moderation effect: ethnic identity affirmation enhanced the level of self‐esteem, but only for those adoptees who perceived a higher degree of national identity affirmation.  相似文献   
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