Volberg G, Chockley A S, Greenlee M W
Institute for Psychology, University of Regensburg, Germany.
Institute for Psychology, University of Regensburg, Germany; Department of Animal Physiology, Zoological Institute, Biocenter Cologne, Germany.
Neuropsychologia. 2017 May;99:101-111. doi: 10.1016/j.neuropsychologia.2017.03.004. Epub 2017 Mar 3.
Grapheme-color synesthetes perceive concurrent colors for some objectively achromatic graphemes (inducers). Using oscillatory responses in the electroencephalogram, we tested the hypothesis that inducers automatically attract spatial attention and, thus, favor a conscious experience of color. Achromatic inducers and real-colored non-inducers were presented to the left or to the right visual hemifield and orientation judgments were required for subsequently presented Gabor patches. The graphemes were irrelevant for the task so that the related brain response was purely stimulus-driven. Synesthetes (n =12), but not an equal number of controls, showed an early theta power increase for inducers presented to the right compared to the left hemifield, with sources in left fusiform gyrus. Alpha power asymmetries indicative of shifts of spatial attention were not observed. Together, synesthetes showed an increased responsiveness to inducers in grapheme processing areas. However, contrary to our hypothesis, inducers did not attract spatial attention in synesthetes.
grapheme - 颜色联觉者会为一些客观上无色彩的字形（诱发刺激）感知到同时出现的颜色。我们利用脑电图中的振荡反应，检验了这样一个假设：诱发刺激会自动吸引空间注意力，从而有利于产生颜色的意识体验。将无色彩的诱发刺激和有真实颜色的非诱发刺激呈现给左或右半视野，并要求对随后呈现的Gabor斑块进行方向判断。这些字形与任务无关，因此相关的大脑反应完全是由刺激驱动的。与对照组数量相等的12名联觉者相比，当诱发刺激呈现给右半视野而非左半视野时，他们早期的θ波功率增加，其来源位于左梭状回。未观察到指示空间注意力转移的α波功率不对称现象。总体而言，联觉者在字形处理区域对诱发刺激的反应增强。然而，与我们的假设相反，诱发刺激在联觉者中并未吸引空间注意力。
