Abstract:
Four experiments were conducted to gain a better understanding of the visual mechanisms related to how integration of partial shape cues provides for recognition of the full shape. In each experiment, letters formed as outline contours were displayed as a sequence of adjacent segments (fragments), each visible during a 17-ms time frame. The first experiment varied the contrast of the fragments. There were substantial individual differences in contrast sensitivity, so stimulus displays in the masking experiments that followed were calibrated to the sensitivity of each participant. Masks were displayed either as patterns that filled the entire screen (full field) or as successive strips that were sliced from the pattern, each strip lying across the location of the letter fragment that had been shown a moment before. Contrast of masks were varied to be lighter or darker than the letter fragments. Full-field masks, whether light or dark, provided relatively little impairment of recognition, as was the case for mask strips that were lighter than the letter fragments. However, dark strip masks proved to be very effective, with the degree of recognition impairment becoming larger as mask contrast was increased. A final experiment found the strip masks to be most effective when they overlapped the location where the letter fragments had been shown a moment before. They became progressively less effective with increased spatial separation from that location. Results are discussed with extensive reference to potential brain mechanisms for integrating shape cues.
摘要:
进行了四个实验,以更好地理解与部分形状线索的整合如何提供完整形状的识别有关的视觉机制。在每个实验中,作为轮廓轮廓形成的字母显示为相邻段(片段)的序列,每个在17毫秒的时间范围内可见。第一个实验改变了碎片的对比度。对比敏感度有很大的个体差异,因此,随后的掩蔽实验中的刺激显示被校准到每个参与者的灵敏度。掩模显示为填充整个屏幕(完整区域)的图案或从图案切片的连续条带,每个条躺在位置的字母片段之前已经显示了。面罩的对比度变化为比字母片段更亮或更暗。全场面具,无论是光明还是黑暗,提供相对较小的确认减值,就像比字母碎片轻的面具条一样。然而,深色带面具被证明是非常有效的,随着掩模对比度的增加,识别障碍的程度变得更大。最后一个实验发现,当它们与之前显示的字母片段的位置重叠时,带状面具最有效。随着与该位置的空间分离增加,它们的效率逐渐降低。讨论了结果,并广泛参考了整合形状线索的潜在脑机制。