Ball Keira, Smith Daniel, Ellison Amanda, Schenk Thomas
Department of Psychology, Durham University, Stockton on Tees, UK.
Neuropsychologia. 2009 May;47(6):1585-91. doi: 10.1016/j.neuropsychologia.2008.11.017. Epub 2008 Nov 24.
The perception-action model proposes that vision for perception and vision for action are subserved by two separate cortical systems, the ventral and dorsal streams, respectively [Milner, A. D., & Goodale, M. A. (1995). The visual brain in action (1st ed.). Oxford: Oxford University Press; Milner, A. D., & Goodale, M. A. (2006). The visual brain in action (2nd ed.). Oxford: Oxford University Press Inc.]. The dorsal stream codes spatial information egocentrically, that is, relative to the observer. Egocentric representations are argued to be highly transient; therefore, it might be expected that egocentric information cannot be used for spatial memory tasks, even when the visual information only needs to be retained for a few seconds. Here, by applying a spatial priming paradigm to a visual search task, we investigated whether short-term spatial memory can use egocentric information. Spatial priming manifests itself in speeded detection times for a target when that target appears in the same location it previously appeared in. Target locations can be defined in either egocentric or allocentric (i.e. relative to other items in the display) frames of reference; however, it is unclear which of these are used in spatial priming, or if both are. Our results show that both allocentric and egocentric cues were used in spatial priming, and that egocentric cues were in fact more effective than allocentric cues for short-term priming. We conclude that egocentric information can persist for several seconds; a conclusion which is at odds with the assumption of the perception-action model that egocentric representations are highly transient.
感知 - 行动模型提出，用于感知的视觉和用于行动的视觉分别由两个独立的皮质系统，即腹侧流和背侧流来支持[米尔纳，A. D.，& 古德尔，M. A.（1995）。行动中的视觉大脑（第1版）。牛津：牛津大学出版社；米尔纳，A. D.，& 古德尔，M. A.（2006）。行动中的视觉大脑（第2版）。牛津：牛津大学出版社公司]。背侧流以自我为中心编码空间信息，也就是说，相对于观察者而言。有人认为以自我为中心的表征是高度短暂的；因此，可以预期以自我为中心的信息不能用于空间记忆任务，即使视觉信息只需要保留几秒钟。在这里，通过将空间启动范式应用于视觉搜索任务，我们研究了短期空间记忆是否可以使用以自我为中心的信息。当目标出现在它之前出现的相同位置时，空间启动表现为目标检测时间的加快。目标位置可以在以自我为中心或异我中心（即相对于显示中的其他项目）的参照系中定义；然而，目前尚不清楚在空间启动中使用的是其中哪一种，或者是否两者都使用。我们的结果表明，在空间启动中同时使用了异我中心和以自我为中心的线索，并且事实上以自我为中心的线索在短期启动中比异我中心的线索更有效。我们得出结论，以自我为中心的信息可以持续几秒钟；这一结论与感知 - 行动模型中以自我为中心的表征是高度短暂的这一假设不一致。
