Morawetz Carmen, Holz Petra, Baudewig Juergen, Treue Stefan, Dechent Peter
MR-Research in Neurology & Psychiatry, Medical Faculty, Georg-August University, Goettingen, Germany.
Vis Neurosci. 2007 Nov-Dec;24(6):817-26. doi: 10.1017/S0952523807070745.
Visual spatial attention has been described as a process that favors the processing of sensory information that falls into the "spotlight of attention." Recent studies have provided support for an ability to split this attentional focus to selectively process spatially separate locations. Using functional magnetic resonance imaging, the signature for the presence of multiple spotlights is the presence of multiple retinotopically specific foci of activation in striate and extrastriate visual areas. We used this approach to investigate the presence of such separable activations as a function of the eccentricity of the spatial foci of attention. Visual stimuli consisted of letters and digits displayed in rapid serial visual presentation (RSVP). Five RSVP streams were presented simultaneously, one in the center of the visual field and one in each visual field quadrant. Subjects had to deploy their attention either to a single peripheral location or two non-contiguous regions performing a match-mismatch judgment. The results show that dividing attention leads to multiple spotlights of attention for central as well as more peripheral locations of the visual field. However, depending on the exact location and width of the attentional spotlights, resulting activation maps might reveal merged activation patterns even in the presence of distinct attentional spotlights.
视觉空间注意力被描述为一个有利于处理落入“注意力焦点”的感官信息的过程。最近的研究为将这种注意力焦点分开以选择性地处理空间上分离的位置的能力提供了支持。使用功能磁共振成像，多个注意力焦点存在的标志是在纹状和纹外视觉区域中存在多个视网膜拓扑特异性激活焦点。我们使用这种方法来研究这种可分离激活的存在与注意力空间焦点的偏心率之间的函数关系。视觉刺激由以快速序列视觉呈现（RSVP）方式显示的字母和数字组成。同时呈现五个RSVP流，一个在视野中心，一个在每个视野象限。受试者必须将注意力部署到单个周边位置或两个不连续区域进行匹配-不匹配判断。结果表明，分配注意力会导致在视野的中央以及更周边位置出现多个注意力焦点。然而，根据注意力焦点的确切位置和宽度，即使存在不同的注意力焦点，最终的激活图可能也会显示出合并的激活模式。
