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91.
An object that moves is spotted almost effortlessly; it "pops out". When the observer is stationary, a moving object is uniquely identified by retinal motion. This is not so when the observer is also moving; as the eye travels through space all scene objects change position relative to the eye producing a complicated field of retinal motion. Without the unique identifier of retinal motion an object moving relative to the scene should be difficult to locate. Using a search task, we investigated this proposition. Computer-rendered objects were moved and transformed in a manner consistent with movement of the observer. Despite the complex pattern of retinal motion, objects moving relative to the scene were found to pop out. We suggest the brain uses its sensitivity to optic flow to "stabilise" the scene, allowing the scene-relative movement of an object to be identified. 相似文献
92.
目的:研究慢性不确定应激对大鼠急性整体热水浴后外周血和脾脏免疫细胞热休克蛋白70(Heat shock protein 70, HSP70)表达的影响。方法:随机将大鼠分成慢性应激组和控制组(每组14只)。通过4周的慢性不确定性应激诱发实验组大鼠明显的抑郁行为,此期间控制组大鼠正常饲养。随后给予大鼠42度整体热水浴刺激,维持直肠温度41度25min。热刺激后6h,采用流式细胞仪测定大鼠外周血和脾脏免疫细胞HSP70 水平。结果:与控制组大鼠相比,慢性应激大鼠在急性热刺激后HSP70合成明显减少。控制组大鼠的所有被检测的免疫细胞热应激后HSP70合成均明显增加。相反,慢性应激大鼠仅在外周血的单核细胞和粒细胞检测到HSP70合成增加,同时升高的水平明显低于控制组大鼠。结论:慢性应激降低大鼠免疫细胞HSP70的热诱导反应,提示HSP70保护性作用减弱可能参与了慢性应激损害免疫细胞功能的生物学过程 相似文献
93.
The examination of blood flow velocity (BFV) changes during the performance of mental tasks is one of the applications of transcranial Doppler (TCD) ultrasonography. The purpose of this review is to summarize the results of the functional TCD literature, to investigate the effects of methodological differences between studies, and to provide guidelines for future research. It is concluded that larger series of more homogeneous groups concerning age and handedness, and stricter criteria for subject selection and laboratory setting are required. The implication of quantitative and qualitative performance measures and psychological parameters (motivation, anxiety, and task anticipation) could also yield important information. We recommend future agreement upon a more standardized methodology. TCD promises to be a useful tool to provide further insight into the cerebral organization and temporal reactivity of the human brain. 相似文献
94.
Tresan DI 《The Journal of analytical psychology》2004,49(2):193-216
This paper is a search for the origins and nature of human consciousness. This portion, the first part of two, takes up a signal work of Jung and one of Freud, both published in 1911 and both deriving thinking as the first embodiment of higher mental functions. Thinking and consciousness (and subsequently spirit) are elaborated in terms of the nature and vicissitudes of libido. Jung's less well understood theory regarding a quantitative libido is particularly addressed as are his non-Cartesian ways of reasoning. Also addressed is Jung's turning away in the final analysis from a frankly metaphysical and transcendent position as compared to the pre-Socratic philosophers with whom focused thinking began in the western world. Differentiation is made between mechanistic and energetic field dynamics in how reality is viewed. 相似文献
95.
Summary Big History – an integral conception of the past since the Big Bang until today – is a novel subject of cross-disciplinary interest. The concept was construed in the 1980–1990s simultaneously in different countries, after relevant premises had matured in the sciences and humanities.Various versions and traditions of Big History are considered in the article. Particularly, most of the Western authors emphasize the idea of equilibrium, and thus reduce cosmic, biological, and social evolution to the mass-energy processes; the informational parameter involving all mental and spiritual aspects are seen as epiphenomena of material structures” complication that do not play their own role in evolution. In Russian tradition ascending to A. Bogdanov, E. Bauer, I. Prigogine, and E. Jantsch, sustainable non-equilibrium patterns are used. This implies attention to the pan-material sources and evolution of mental capacities and spiritual culture (as basic anti-entropy instruments) and humans” growing intervention in the material processes on Earth and outside it.The non-equilibrium approach in the context of modern control and self-organization theories, alters the portrayal of the past, and still more dramatically, estimation of the civilization’s potential perspectives. 相似文献
96.
Since blushing is difficult to detect in people with dark skin, their experience of blushing may differ fundamentally from people with fair skin. To investigate this issue, cheek temperature and forehead blood flow were measured in 16 Caucasians and 16 Indians during mental arithmetic and singing. Caucasians (particularly females) thought that they blushed more intensely than Indians, and also reported greater self-consciousness when singing. Vascular responses did not differ between groups. However, skin tone moderated the association between vascular responses and ratings of self-consciousness, blushing intensity, blushing propensity and fear of negative evaluation. These findings support the notion that the visibility of blushing influences the nature of emotions experienced in embarrassing social encounters. 相似文献
97.
The perilous disease in the worldwide now a days is brain tumor. Tumor affects the brain by damaging healthy tissues or intensifying intra cranial pressure. Hence, rapid growth in tumor cells may lead to death. Therefore, early brain tumor diagnosis is a more momentous task that can save patient from adverse effects. In the proposed work, the Grab cut method is applied for accurate segmentation of actual lesion symptoms while Transfer learning model visual geometry group (VGG-19) is fine-tuned to acquire the features which are then concatenated with hand crafted (shape and texture) features through serial based method. These features are optimized through entropy for accurate and fast classification and fused vector is supplied to classifiers. The presented model is tested on top medical image computing and computer-assisted intervention (MICCAI) challenge databases including multimodal brain tumor segmentation (BRATS) 2015, 2016, and 2017 respectively. The testing results with dice similarity coefficient (DSC) achieve 0.99 on BRATS 2015, 1.00 on BRATS 2015 and 0.99 on BRATS 2017 respectively. 相似文献
98.
Rolando Grave de Peralta Menendez Sara González Andino Lucas Perez Pierre W. Ferrez José del R. Millán 《Cognitive processing》2005,6(1):59-64
Recent experiments have shown the possibility of using the brain electrical activity to directly control the movement of robots or prosthetic devices in real time. Such neuroprostheses can be invasive or non-invasive, depending on how the brain signals are recorded. In principle, invasive approaches will provide a more natural and flexible control of neuroprostheses, but their use in humans is debatable given the inherent medical risks. Non-invasive approaches mainly use scalp electroencephalogram (EEG) signals and their main disadvantage is that these signals represent the noisy spatiotemporal overlapping of activity arising from very diverse brain regions, i.e., a single scalp electrode picks up and mixes the temporal activity of myriads of neurons at very different brain areas. In order to combine the benefits of both approaches, we propose to rely on the non-invasive estimation of local field potentials (LFP) in the whole human brain from the scalp measured EEG data using a recently developed inverse solution (ELECTRA) to the EEG inverse problem. The goal of a linear inverse procedure is to de-convolve or un-mix the scalp signals attributing to each brain area its own temporal activity. To illustrate the advantage of this approach we compare, using an identical set of spectral features, classification of rapid voluntary finger self-tapping with left and right hands based on scalp EEG and non-invasively estimated LFP on two subjects using a different number of electrodes.
相似文献
Rolando Grave de Peralta MenendezEmail: Phone: +41-22-3728295Fax: +41-22-3728358 |
99.
100.
Quinlan et al. [Quinlan, p., van der Mass, H., Jansen, B., Booij, O., & Rendell, M. (this issue). Re-thinking stages of cognitive development: An appraisal of connectionist models of the balance scale task. Cognition, doi:10.1016/j.cognition.2006.02.004] use Latent Class Analysis (LCA) to criticize a connectionist model of development on the balance-scale task, arguing that LCA shows that this model fails to capture a torque rule and exhibits rules that children do not. In this rejoinder we focus on the latter problem, noting the tendency of LCA to find small, unreliable, and difficult-to-interpret classes. This tendency is documented in network and synthetic simulations and in psychological research, and statistical reasons for finding such unreliable classes are discussed. We recommend that LCA should be used with care, and argue that its small and unreliable classes should be discounted. Further, we note that a preoccupation with diagnosing rules ignores important phenomena that rules do not account for. Finally, we conjecture that simple extensions of the network model should be able to achieve torque-rule performance. 相似文献