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31.
Texture gradients can reveal surface orientation in a manner similar to shape from shading, and therefore provide an important cue for object recognition. In this study, we tested whether a complex 3-D object, such as a face, can be identified from texture gradients alone. The stimuli were laser-scanned faces for which the texture element was a fractal-noise pattern mapped onto the 3-D surface. An eight-alternative forced choice task was used in which participants matched a face defined by texture gradients to one of eight faces defined by shape from shading (Experiment 1) or by texture gradients (Experiment 2). On average, participants scored 24% and 18%, respectively, above chance in these experiments. Although this performance was much poorer than the performance based entirely on shape-from-shading stimuli (Experiment 3), the results suggest that texture gradient information may be used to recover surface geometry of complex objects.  相似文献   
32.
王红  李薇 《管子学刊》2005,(3):25-28
晏婴以极忠尽谏闻名,而其劝谏的主要内容便是要齐君效法古之贤君爱民、重民,体现出中国传统文化中的民本思想.本文以《晏子春秋》为据,描述晏婴的谏诤形象和高超的进谏艺术与技巧.  相似文献   
33.
Response time (RT) generally slows with aging, but the contribution of structural brain changes to this slowing is unknown. We used voxel-based morphometry (VBM) to determine gray matter (GM) and white matter (WM) brain volumes in 9 middle-aged adults (38–58 years old) and 9 seniors (66–82 years old). We correlated brain volumes with RT assessed in both a simple visual stimulus-response task and a visual continuous recognition memory task. No GM correlations with simple RT were significant; there was one WM correlation in the right fusiform gyrus. In the memory task, faster RT was correlated (p<.05, corrected) with less GM in the globus pallidus, the parahippocampus, and the thalamus for both groups. Several Brodmann areas (BA) differed between the groups such that in each area, less GM was correlated with slower RTs in the middle-aged group but with faster RTs in the senior group (BAs 19, 37, 46, 9, 8, 6, 13, 10, 41, and 7). The results suggest that individual differences in specific brain structure volumes should be considered as potential moderating factors in cognitive brain imaging studies.  相似文献   
34.
Social identity approaches assume that social identification affects both self-conception and intergroup orientation. The authors contend that such social identification effects are accentuated when people hold a fixed view of human character and attribute immutable dispositions to social groups. To these individuals, social identities are immutable, concrete entities capable of guiding self-conception and intergroup orientation. Social identification effects are attenuated when people hold a malleable view of human character and thus do not view social identities as fixed, concrete entities. The authors tested and found support for this contention in three studies that were conducted in the context of the Hong Kong 1997 political transition, and discussed the findings in terms of their implications for self-conceptions and the meaning of social identification.  相似文献   
35.
Variability in rhythmic movements has been interpreted as a signature of internal or peripheral noise processes. Grounded in an oscillator interpretation, this study hypothesized that period variability and drift arises from the asymmetry between target period and the limb's intrinsic dynamics. Participants synchronized to 7 target periods, swinging 1 of 3 pendulums in a continuation paradigm; 3 periods were longer, 3 shorter, and 1 identical to the preferred period. Results supported 5 predictions: Drift toward the preferred period was observed that scaled with the asymmetry. Variability was lowest for symmetry conditions and increased with the asymmetry. Variability decreased concomitant with the approach toward the preferred period. Periods exponentially approached the preferred period with positive autocorrelations up to 10 cycles.  相似文献   
36.
We previously reported that a total methanolic extract of the underground part of Angelica gigas Nakai (Umbelliferae) (here-in-after abbreviated AG) significantly inhibited acetylcholinesterase (AChE) activity. We characterized 12 coumarin derivatives including both decursin and decursinol from extracts of AG. In this study, we evaluated the anti-amnestic activity of decursin, a major coumarin constituent isolated from AG, in vivo using ICR mice with amnesia induced by scopolamine (1 mg/kg body weight, s.c.). Decursin, when administered to mice at 1 and 5 mg/kg body weight i.p., significantly ameliorated scopolamine-induced amnesia as measured in both the passive avoidance test and the Morris water maze test. Moreover, decursin significantly inhibited AChE activity by 34% in the hippocampus of treated mice. These results indicate that decursin may exert anti-amnestic activity in vivo through inhibition of AChE activity in the hippocampus.  相似文献   
37.
It is thought that circadian rhythms may influence learning and memory processes. However, research supporting this view does not dissociate a mnemonic impairment from other performance deficits. Furthermore, published reports do not specify the type of memory system influenced by the circadian system. The present study assessed the effects of phase shifting on acquisition and expression of place navigation in the water maze, a task sensitive to hippocampal dysfunction. The results showed that phase-shifting circadian rhythms in rats impaired the expression of place information on a retention test but not initial acquisition or encoding of place information. These results suggest that disruption of circadian rhythms may impair consolidation of previously encoded hippocampal place information.  相似文献   
38.
39.
We investigated relationships between Chinese children's imaginary companions (ICs) and peer relationships and social competence in 160 children, aged 5–6 years old. Children and their mothers participated in the interviews regarding the details of the children's ICs, including the type of the companion and the quality of the child–IC relationship. Peer relationships were assessed using sociometric nomination and perceived popularity nomination. Teachers rated children's social competence. Here, 55 children (34.3%) were deemed to have engaged in imaginary companion play. There was no relationship between imaginary companion types and child–IC relationship qualities. Children with invisible friends received more positive nominations than children with personified objects. Children with egalitarian relationships received more positive nominations and popularity nominations, but fewer negative nominations and unpopularity nominations than children with hierarchical relationships. Compared with children with hierarchical relationships, teachers rated the children with egalitarian relationships higher in social competence. The results suggest that imaginary companion types and relationship qualities may represent different dimensions of imaginary companions, calling attentions to the different mechanisms underlying imaginary companion types and relationship qualities with respect to social functioning.  相似文献   
40.
Correlational evidence indicates that materialistic individuals experience relatively low levels of well-being. Across four experiments, we found that situational cuing can also trigger materialistic mind-sets, with similarly negative personal and social consequences. Merely viewing desirable consumer goods resulted in increases in materialistic concerns and led to heightened negative affect and reduced social involvement (Experiment 1). Framing a computer task as a "Consumer Reaction Study" led to a stronger automatic bias toward values reflecting self-enhancement, compared with framing the same task as a "Citizen Reaction Study" (Experiment 2). Consumer cues also increased competitiveness (Experiment 3) and selfishness in a water-conservation dilemma (Experiment 4). Thus, the costs of materialism are not localized only in particularly materialistic people, but can also be found in individuals who happen to be exposed to environmental cues that activate consumerism-cues that are commonplace in contemporary society.  相似文献   
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