The University of Pennsylvania, Philadelphia, PA 19104, USA.
J Cogn Neurosci. 2010 Aug;22(8):1739-53. doi: 10.1162/jocn.2009.21322.
Studies in semantics traditionally focus on knowledge of objects. By contrast, less is known about how objects relate to each other. In an fMRI study, we tested the hypothesis that the neural processing of categorical spatial relations between objects is distinct from the processing of the identity of objects. Attending to the categorical spatial relations compared with attending to the identity of objects resulted in greater activity in superior and inferior parietal cortices (especially on the left) and posterior middle frontal cortices bilaterally. In an accompanying lesion study, we tested the hypothesis that comparable areas would be necessary to represent categorical spatial relations and that the hemispheres differ in their biases to process categorical or coordinate spatial relations. Voxel-based lesion symptom mapping results were consistent with the fMRI observations. Damage to a network comprising left inferior frontal, supramarginal, and angular gyri resulted in behavioral impairment on categorical spatial judgments. Homologous right brain damage also produced such deficits, albeit less severely. The reverse pattern was observed for coordinate spatial processing. Right brain damage to the middle temporal gyrus produced more severe deficits than left hemisphere damage. Additional analyses suggested that some areas process both kinds of spatial relations conjointly and others distinctly. The left angular and inferior frontal gyrus processes coordinate spatial information over and above the categorical processing. The anterior superior temporal gyrus appears to process categorical spatial information uniquely. No areas within the right hemisphere processed categorical spatial information uniquely. Taken together, these findings suggest that the functional neuroanatomy of categorical and coordinate processing is more nuanced than implied by a simple hemispheric dichotomy.
传统的语义学研究侧重于对物体的知识的研究。相比之下，人们对物体之间的关系知之甚少。在一项 fMRI 研究中，我们验证了这样一个假设，即物体之间的类别空间关系的神经处理与物体的身份处理是不同的。与关注物体的身份相比，关注类别空间关系会导致顶叶和下顶叶皮质（尤其是左侧）以及双侧后中额皮质的活动增加。在一项伴随的损伤研究中，我们验证了这样一个假设，即需要类似的区域来表示类别空间关系，并且大脑半球在处理类别或坐标空间关系时存在偏见。体素基于病变症状映射的结果与 fMRI 观察结果一致。左额下回、缘上回和角回组成的网络损伤导致在类别空间判断上出现行为障碍。同源的右脑损伤也会产生类似的缺陷，尽管程度较轻。坐标空间处理则观察到相反的模式。颞中回右侧大脑损伤比左侧大脑损伤产生更严重的缺陷。进一步的分析表明，一些区域同时处理这两种类型的空间关系，而另一些区域则单独处理。左角回和额下回除了处理类别信息外，还处理坐标空间信息。额上回前部似乎独特地处理类别空间信息。右半球内没有任何区域单独处理类别空间信息。综上所述，这些发现表明，类别和坐标处理的功能神经解剖结构比简单的半球二分法所暗示的更为复杂。
