Slotnick Scott D, Moo Lauren R
Department of Psychology, McGuinn Hall, Boston College, Chestnut Hill, MA 02467, USA.
Neuropsychologia. 2006;44(9):1560-8. doi: 10.1016/j.neuropsychologia.2006.01.018. Epub 2006 Mar 3.
During visual spatial perception of multiple items, the left hemisphere has been shown to preferentially process categorical spatial relationships while the right hemisphere has been shown to preferentially process coordinate spatial relationships. We hypothesized that this hemispheric processing distinction would be reflected in the prefrontal cortex during categorical and coordinate visual spatial memory, and tested this hypothesis using functional magnetic resonance imaging (fMRI). During encoding, abstract shapes were presented in the left or right hemifield in addition to a dot at a variable distance from the shape (with some dots on the shape); participants were instructed to remember the position of each dot relative to the shape. During categorical memory retrieval, each shape was presented centrally and participants responded whether the previously corresponding dot was 'on' or 'off' of the shape. During coordinate memory retrieval, each shape was presented centrally and participants responded whether the previously corresponding dot was 'near' or 'far' from the shape (relative to a reference distance). Consistent with our hypothesis, a region in the left prefrontal cortex (BA10) was preferentially associated with categorical visual spatial memory and a region in the right prefrontal cortex (BA9/10) was preferentially associated with coordinate visual spatial memory. These results have direct implications for interpreting previous findings that the left prefrontal cortex is associated with source memory, as this cognitive process is categorical in nature, and the right prefrontal cortex is associated with item memory, as this process depends on the precise spatial relations among item features or components.
在对多个物体进行视觉空间感知时，研究表明左半球优先处理分类空间关系，而右半球优先处理坐标空间关系。我们假设这种半球处理差异在分类和坐标视觉空间记忆过程中会在前额叶皮层中得到体现，并使用功能磁共振成像（fMRI）对这一假设进行了测试。在编码过程中，除了在与形状有可变距离的位置（有些点在形状上）呈现一个点外，还在左半视野或右半视野呈现抽象形状；参与者被要求记住每个点相对于形状的位置。在分类记忆检索过程中，每个形状在中央呈现，参与者回答之前相应的点是在形状“上”还是“不在”形状上。在坐标记忆检索过程中，每个形状在中央呈现，参与者回答之前相应的点是离形状“近”还是“远”（相对于参考距离）。与我们的假设一致，左前额叶皮层（BA10）中的一个区域优先与分类视觉空间记忆相关，右前额叶皮层（BA9/10）中的一个区域优先与坐标视觉空间记忆相关。这些结果对于解释先前的研究结果具有直接意义，即左前额叶皮层与源记忆相关，因为这种认知过程本质上是分类性的，而右前额叶皮层与项目记忆相关，因为这个过程依赖于项目特征或成分之间精确的空间关系。
