Anton-Erxleben Katharina, Henrich Christian, Treue Stefan
Cognitive Neuroscience Laboratory, German Primate Center, Goettingen, Germany.
J Vis. 2007 Aug 23;7(11):5.1-9. doi: 10.1167/7.11.5.
Spatial attention shifts receptive fields in monkey extrastriate visual cortex toward the focus of attention (S. Ben Hamed, J. R. Duhamel, F. Bremmer, & W. Graf, 2002; C. E. Connor, J. L. Gallant, D. C. Preddie, & D. C. Van Essen, 1996; C. E. Connor, D. C. Preddie, J. L. Gallant, & D. C. Van Essen, 1997; T. Womelsdorf, K. Anton-Erxleben, F. Pieper, & S. Treue, 2006). This distortion in the retinotopic distribution of receptive fields might cause distortions in spatial perception such as an increase of the perceived size of attended stimuli. Here we test for such an effect in human subjects by measuring the point of subjective equality (PSE) for the perceived size of a neutral and an attended stimulus when drawing automatic attention to one of two spatial locations. We found a significant increase in perceived size of attended stimuli. Depending on the absolute stimulus size, this effect ranged from 4% to 12% and was more pronounced for smaller than for larger stimuli. In our experimental design, an attentional effect on task difficulty or a cue bias might influence the PSE measure. We performed control experiments and indeed found such effects, but they could only account for part of the observed results. Our findings demonstrate that the allocation of transient spatial attention onto a visual stimulus increases its perceived size and additionally biases subjects to select this stimulus for a perceptual judgment.
空间注意力会使猴子纹外视觉皮层中的感受野朝着注意力焦点移动（S. 本·哈梅德、J. R. 杜阿梅尔、F. 布雷默和W. 格拉夫，2002年；C. E. 康纳、J. L. 加兰特、D. C. 普雷迪和D. C. 范埃森，1996年；C. E. 康纳、D. C. 普雷迪、J. L. 加兰特和D. C. 范埃森，1997年；T. 沃梅尔斯多夫、K. 安东 - 埃尔克斯莱本、F. 皮珀和S. 特鲁埃，2006年）。感受野视网膜拓扑分布中的这种扭曲可能会导致空间感知的扭曲，例如被关注刺激的感知大小增加。在这里，我们通过测量在自动将注意力吸引到两个空间位置之一时，中性刺激和被关注刺激的感知大小的主观相等点（PSE），来测试人类受试者中的这种效应。我们发现被关注刺激的感知大小显著增加。根据绝对刺激大小的不同，这种效应的范围在4%到12%之间，并且对较小刺激的影响比较大刺激更为明显。在我们的实验设计中，注意力对任务难度的影响或线索偏差可能会影响PSE测量。我们进行了对照实验，确实发现了这样的影响，但它们只能解释部分观察结果。我们的研究结果表明，将短暂的空间注意力分配到视觉刺激上会增加其感知大小，并且还会使受试者在进行感知判断时更倾向于选择该刺激。
