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Tracking an object through feature space 总被引:7,自引:0,他引:7
Visual attention allows an observer to select certain visual information for specialized processing. Selection is readily apparent in 'tracking' tasks where even with the eyes fixed, observers can track a target as it moves among identical distractor items. In such a case, a target is distinguished by its spatial trajectory. Here we show that one can keep track of a stationary item solely on the basis of its changing appearance--specified by its trajectory along colour, orientation, and spatial frequency dimensions--even when a distractor shares the same spatial location. This ability to track through feature space bears directly on competing theories of attention, that is, on whether attention can select locations in space, features such as colour or shape, or particular visual objects composed of constellations of visual features. Our results affirm, consistent with a growing body of psychophysical and neurophysiological evidence, that attention can indeed select specific visual objects. Furthermore, feature-space tracking extends the definition of visual object to include not only items with well defined spatio-temporal trajectories, but also those with well defined featuro-temporal trajectories. 相似文献
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一个新的哈密顿振幅方程的精确解 总被引:4,自引:1,他引:3
张辉群 《青岛大学学报(自然科学版)》2002,15(2):54-55
本文用齐交平衡法求出了哈密顿振幅方程的精确解。这是齐次平衡方法求解微方程的又一应用。 相似文献
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