【摘要】 本文通过测量人类视觉系统对不同空间频率的正弦条纹作出现、消失和反转变化的反应时间,考察了空间频率对反应时间的影响,结果表明,反应时间随空间频率的增高而呈递增的趋势。当刺激由倾斜45°的某一空间频率的正弦条纹变化为另一空间频率的竖直正弦条纹时,RT主要由两者中较低的空间频率决定。此处,进一步的实验表明,较大的图形比较小的图形更易于识别。同一图形中的轮廊和细节不能同时识别。这说明,人类视觉系统优先于处理刺激图象中较低的空间频率成分(对应于图象的轮廊),然后再处理较高的频率成分(对应于细节),而且两者只能串行地进行。通过进一步的理论分析和推导,认为造成这种现象的原因是人类视觉系统内部计算的有限性。更多还原

【Abstract】 The influence of spatial frequency on the reaction times(RTs)to the onset, offset and contrast reversal of sinusoidal grationgs is investigated. The results show that RTs to these changes are increased with the spatial frequencies of the gratings. It is discovered in our experiments that the RTs to the change of the stimulus from the 45 degrees tilted grating of one spatial frequency to the vertical grating of another spatial frequency is determined by the lower spatial frequency. In the other experiments, we find that large patterns can be recognized more rapidly than small patterns, In addition, we find that the outline and the detail of a pattern can not be recognized simultaneously. This suggests that the human vision system processes lower spatial frequency components (corresponding to outlines) prior to higher ones (corresponding to details) and must processes them sequentially. In conclusion, we think this phenomena is the appearance of the computational limitation of human vision system.更多还原