Matsuo Kayako, Kato Chikako, Okada Tomohisa, Moriya Tetsuo, Glover Gary H, Nakai Toshiharu
Medical Vision Group, Life Electronics Research Laboratory, AIST, Osaka, Japan.
Brain Res Cogn Brain Res. 2003 Jul;17(2):263-72. doi: 10.1016/s0926-6410(03)00114-9.
The role of finger writing movements in recognizing Japanese ideographic characters (Kanji) was investigated using functional magnetic resonance imaging at 3 T. A total of 12 healthy native Japanese-speaking volunteers were studied while counting the number of strokes in ideographic characters. In experiment 1, a representation of the pronunciation of an ideographic character was displayed using Japanese syllabic characters. Volunteers were required to count the strokes of the ideographic character corresponding to the displayed phonogram. This procedure included retrieval and generation of ideographic characters. In experiment 2, the ideographic character itself was displayed and the volunteers counted its strokes. This procedure focused on visuospatial imagery processes. Each experiment was conducted under two different motor conditions. One condition allowed the subject to use finger movements to count the strokes, while the other disallowed any finger movements. In both experiments, movement-allowed conditions duly activated the primary motor area. The phonogram-displayed and movement-disallowed condition induced an augmented activation in a part of the left premotor area, which was assumed to be Exner's area. This area might have been activated by a demand for sequential generation of character graphemes that corresponded to the phonogram displayed. The ideographic-character-displayed and movement-disallowed condition activated the dorsal occipitoparietal areas and the primary visual area, which might be involved in the visuospatial mental imagery processes. These results suggest that execution of finger movements during stroke counting of ideographic characters lightens the neural loads for grapheme generation on Exner's area and for the visuospatial imagery processes on the dorsal pathway.
利用3T功能磁共振成像技术，研究了手指书写动作在识别日文字符（汉字）中的作用。共有12名以日语为母语的健康志愿者参与了研究，他们在数汉字笔画数时接受了检测。在实验1中，使用日语音节字符来呈现一个汉字的读音。要求志愿者数与所呈现音节相对应的汉字的笔画数。这个过程包括汉字的检索和生成。在实验2中，直接呈现汉字本身，让志愿者数其笔画数。这个过程侧重于视觉空间意象过程。每个实验都在两种不同的运动条件下进行。一种条件是允许受试者用手指动作来数笔画，另一种条件是不允许任何手指动作。在两个实验中，允许运动的条件都适时地激活了初级运动区。呈现音节且不允许运动的条件在左前运动区的一部分诱发了增强激活，这部分区域被认为是埃克斯纳区。这个区域可能是由于需要按顺序生成与所呈现音节相对应的字符字素而被激活的。呈现汉字且不允许运动的条件激活了枕顶叶背侧区域和初级视觉区，这可能与视觉空间心理意象过程有关。这些结果表明，在数汉字笔画时执行手指动作，减轻了埃克斯纳区生成字素以及背侧通路视觉空间意象过程的神经负荷。
