We aimed to determine the functional localisation of right-left discrimination (RLD) by functional MRI (fMRI). In this study, 16 male volunteers were examined. There were three task sessions: one active and two baseline tasks. During the baseline tasks participants were instructed to show numbers with their fingers. The first baseline task was performed with the right hand, the second one with the left hand. During the active (RLD) task participants were also instructed to show numbers. The difference between baseline and active tasks was that during the active task the hand with which the participant should perform the instruction was assigned randomly. Thus, participants were unaware which hand should be used before the instruction command. During RLD, activations occurred in the right-sided frontal, precuneus, postcentral, angular, lingual, and superior temporal gyri. Activations also appeared in the left-sided temporal gyri and precuneus. Of the activations, 76.7% appeared in the right hemisphere, 23.3% in the left hemisphere. Conclusively, we found that RLD is mainly related to the right hemisphere, and requires activation of the parieto-temporo-occipital junction and the visual system including cuneus, precuneus, and gyrus lingualis.

中文翻译：

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左右歧视与右半球有关。

我们旨在通过功能性磁共振成像（fMRI）确定左右歧视（RLD）的功能定位。在这项研究中，检查了16名男性志愿者。一共有三个任务会话：一个活动任务和两个基线任务。在基线任务中，指示参与者用手指显示数字。第一个基线任务用右手执行，第二个任务用左手执行。在活动（RLD）任务期间，还指示参与者显示数字。基线任务和主动任务之间的区别在于，在主动任务期间，参与者应该随机执行的手的分配。因此，参与者不知道在指示命令之前应该使用哪只手。在RLD期间，激活发生在右侧额骨，前突，中央后，角，舌，和颞上回。激活也出现在左侧颞回和早突。在激活中，右半球出现76.7％，左半球出现23.3％。结论是，我们发现RLD主要与右半球有关，并且需要激活顶颞枕连接和视觉系统，包括楔形肌，前突神经和舌状回。