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851.
Weight-based derogatory media consist of derogation of celebrities for failing to meet the thin ideal. This study examined the impact of weight-based derogatory media on women's body satisfaction, appearance self-esteem, fear of negative appearance evaluation, and negative affect. Female undergraduates (N = 240) were exposed to either tabloid-style pictures and articles derogating average size celebrities for gaining weight, or to the same images accompanied by neutral information. Women in the derogation condition reported greater fear of negative appearance evaluation than did women in the neutral media condition. Contrary to predictions, women low in maladaptive body image investment reported lower body satisfaction and appearance self-esteem in the derogatory media condition than they did in the neutral condition, while women high in maladaptive investment did not differ across conditions. Highly invested women's unexpected reaction may be understood as a defence against a threat to a valued domain of the self.  相似文献   
852.
The present study focuses on the effect of selective attention on causal learning. Three effects of the level of attention to predictive symptoms in positive and negative contingency learning tasks are reported. First, participants accurately detected a positive relationship between an incidental cue and a contingent outcome, although judgements were slightly lower than those for the attended cue. Second, participants were unable to detect negative relationships between incidental cues and outcomes, which suggests a major role of selective attention in this type of learning. Third, participants retrieved the frequency of each trial type more accurately in the attended conditions than in the incidental conditions. These findings show how attention guides and constrains human causal learning and reveal an inattentional blindness effect for negative contingency learning.  相似文献   
853.
Inhibition of return (IOR) consists of slower reaction times in response to stimuli appearing at previously attended or inspected locations. The exact mechanisms underlying the effect have not yet been determined. In the present work, we manipulated two variables, target duration and intervening event (fixation cue between cue and target), through which we modulated the IOR effect as a function of task. When the target was presented until response, the presence of an intervening event made the cueing effect more negative in all tasks, although facilitation in the absence of an intervening event was only observed in discrimination and go–no-go tasks. When the target duration was 50 ms, the effect of the intervening event on cueing was also only observed for the discrimination and go–no-go tasks. Target duration had no effect at all in the discrimination task. Possible mechanisms for these modulations (detection cost and spatial selection benefit, both of which are based on cue–target integration processes) are discussed.  相似文献   
854.
Neuroimaging studies have described the functional neuroanatomy of mental imagery. Taken separately, specific studies vary in the nature of the task used and are limited by statistical power and sensitivity. We took advantage of a multistudy PET database of 54 subjects acquired in our laboratory to reveal the neural bases of spatial versus object mental imagery tasks. Our first goal was to evaluate to what extent the activated foci elicited by both object and spatial studies overlap. A second aim was to compare activations elicited by spatial imagery tasks to those elicited by object imagery tasks. We also explored applying regression analyses to the relationships between the scores on the Mental Rotations Test (MRT) and changes in regional cerebral blood flow (rCBF) during spatial and object imagery tasks. This meta‐analysis yielded the following observations: (1) both spatial and object imagery tasks shared a common neural network composed of occipitotemporal (ventral pathway) and occipitoparietal (dorsal pathway) regions and also by a set of frontal regions (related to memory); (2) the superior parietal cortex was more strongly implicated during spatial imagery; (3) object imagery specifically engaged the anterior part of the ventral pathway, including the fusiform, parahippocampal, and hippocampal gyrus; (4) object imagery activated the early visual cortex, whereas spatial imagery induced a deactivation of the early visual cortex; (5) blood flow values in some of the regions noted above were positively correlated with scores on the MRT: the higher the subjects performed on the MRT, the more pronounced the rCBF was in these regions. These results may reconcile some of the apparent discrepancies among previous studies concerning the activation of early visual cortex in mental imagery. They also contribute to a better knowledge of the neural bases of object and spatial mental imagery.  相似文献   
855.
Previous work has suggested that there may be a relationship between the magnitude of inhibition of return (IOR) and the number of possible responses in the perceptual‐motor task. To test this possibility, the present experiment used a display that contained four horizontally aligned cue/target locations. In different blocks of trials, subjects responded to the target either with a one‐response detection key press, a two‐response localisation key press, or a four‐response localisation key press. The results showed the largest magnitude of IOR was found in the one‐response condition and the least in the four‐response condition. These results suggest that IOR may be most effective in inhibiting relatively prepotent responses and the inhibitory effect weakens when responses require more intricate sensorimotor mappings.  相似文献   
856.
Abstract

A number of cross-language priming experiments are reported that evaluate whether word meanings in the first and second language are represented in common or separate systems. A masked priming procedure was used on the assumption that when prime awareness is limited, any priming effects directly reveal the underlying structure of the semantic system. Primes were presented in the subjects' first language, while targets were in their second language. Priming effects were obtained for word pairs that were semantically highly similar but not translation equivalents, for example fence-haie (= hedge in French), suggesting that words in the two languages share common elements of semantic code. Priming was also obtained between translation equivalents which, in conjunction with the results for semantically similar pairs, is most naturally interpreted in terms of partially shared semantic representations. However, no masked priming effects were obtained between associated pairs of relatively low semantic similarity, for example shoe-pied (= foot in French), whereas such pairs did produce an effect when primes were unmasked. The results are discussed in terms of limitations on the semantic activation produced by masked words, and the role of collocational relationships in priming between associated words in the same language.  相似文献   
857.
The spatial Stroop effect (slower left/right responses to left/right pointing arrows when they appear at spatially incongruent than at congruent locations) has often been used to examine the processing of irrelevant spatial information. We present data from two experiments in which the magnitude of such location-based interference is drastically reduced when the location of the arrow is precued by a spatial noninformative cue. The main aim of the present study was to clarify whether such modulation takes place at perceptual or at response-related stages of processing. First, we manipulated the spatial compatibility between the direction of the arrow and the location of the response so that each subject would respond with spatially compatible vs. incompatible key presses for each half of the experiment. We found that such manipulation did not have any effect on the standard reduction of the congruency effect by peripheral cues. In a second experiment, subjects made left/right key presses to directional arrows pointing bottom/up, which could appear equally often at left/right/bottom/up locations. In cued trials, we found a reduction of the congruency effect on the vertical axis (stimulus location-direction congruency), whereas congruency was unaffected by cueing in targets presented on the horizontal axis (stimulus-response location congruency). According to these results, we conclude that spatial noninformative cues modulate spatial Stroop interference by reducing the conflict between stimulus dimensions at perceptual- rather than motor-related stages of processing.  相似文献   
858.
Lexical–chromatic synaesthesia is a condition in which letters and/or words elicit percepts of synaesthetic colours, termed photisms. Anecdotal data suggest that synaesthetes are particularly sensitive to inconsistencies between their synaesthetic percepts and the real world, e.g., it can be annoying and unpleasant for them to see a letter printed in a colour different than the respective photism colour. For R, a synaesthete subject who participated in the present study, the photisms possess specific emotional values (a red photism is pleasing and attractive, green is repulsive and unpleasant, etc.). In contrast to the anecdotal data, R does not always find the colour–photism incongruence to be disturbing. More importantly, he states that it is the emotional coherence between the stimulus and the corresponding photism that matters. In a series of experiments, we studied this new concept of emotional coherence on three levels—subjective (self-report), behavioural, and physiological, corroborating R's introspective statements. Besides the implications of the concept of coherence itself, the results presented here suggest that even highly subjective cognitive constructs can be approached and measured experimentally, uncovering the workings of the underlying psychophysiological mechanisms.  相似文献   
859.
Learning and adult neurogenesis: survival with or without proliferation?   总被引:8,自引:0,他引:8  
Recent high quality papers have renewed interest in the phenomenon of neurogenesis within the adult mammalian brain. Many studies now show that neurogenesis can be modulated by environmental factors including physical activity, stress, and learning. These findings have considerable implications for neuroscience in general, including the study of learning and memory, neural network plasticity, aging, neurodegeneration, and the recovery from brain injury. Although new light has been shed on this field, many contradictory findings have been reported. Here we propose two principle issues which underlie these inconsistencies, with particular focus on the interaction between learning and neurogenesis. The first issue relates to the basic methodology of measuring the generation of new brain cells, i.e., proliferation, as compared to survival of the newly made cells. Mostly, measures of neurogenesis reported are a combination of proliferation and survival, making it impossible to distinguish between these separate processes. The second aspect is in regards to the role of environmental factors which can affect both proliferation and survival independently. Especially the interaction between stress and learning is of importance since these might counteract each other in some circumstances. Reviewing the literature while taking these issues into account indicates that, in contrast to some findings, cell proliferation in the dentate gyrus of the hippocampus as a result of learning cannot be ruled out yet. On the other hand, increased survival of granule cells in the dentate gyrus as a result of hippocampal-dependent learning has been clearly demonstrated. Moreover, this learning-induced survival of granule cells, which were born before the actual learning experience, might provide a molecular mechanism for the 'use it or lose it' principle.  相似文献   
860.
This study focused on the implications of parents' structuring of their children's home lives for the friendships of their children. Participants were 224 elementary‐school children (108 girls and 116 boys) from four grade levels in two schools in Aix‐en‐Provence, France. Most of the families were of middle or high socio‐economic status. The participating children were seen twice during the same school year in order to assess the stability of their friendship choices and the quality of their friendships. We used Lautrey's (1989) questionnaire in order to assess the parents' styles in the structuring of family life and related child‐rearing practice. This questionnaire delineates three structuring styles: 1) rigid, characterized by considerable imposition of routines with little leeway for exceptional circumstances; 2) flexible, in which established routines can be modified as circumstances dictate; and 3) laissez‐faire, characterized by an absence of predictability and routine. We measured friendship quality by means of Friendship Quality Scale developed by Bukowski, Hoza, and Boivin (1989). This scale consists of 23 items representing five dimensions: companionship, help, security, closeness and conflict. This tool was designed to elicit children's perceptions of a specific relationship with a friend. Results indicated a significant link between parenting style and both of the dimensions of child friendship we studied. Children from homes characterized by a laissez‐faire style of parenting have friendships with more positive features than children from homes with flexible or rigid styles. We also found that friendships were generally less stable and rated as less positive than in similar studies conducted in other countries.  相似文献   
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