Trial manufacture of visual field specific stimulator by means of computer image frame memory and an application to brain metabolic mapping.

在本研究计画中，我们取得两项主要成果：第一是制作一视觉刺激器，并在电生理单一单位记录中显示其有效性。二是将其应用于脑代谢图的绘制，我们已经在视觉记忆的研究中展示了使用“分形图案”的优点。在本项目中，我们的视觉刺激器是通过修改的FBX 24（Texnai）图像帧存储系统。该刺激器利用FBX 24的缩放、平移和滚动功能，成功地产生了分形图案，并在17毫秒内将其以任何大小呈现在视野的任何位置。通过使用这种刺激器，我们发现，在颞叶皮层的形状选择性神经活动是高度选择性的图像信息，是独立的物理属性，如大小，方向，颜色或位置的刺激。在海马体中，我们发现神经元活动与刺激显示的位置有关。这一发现支持了海马体参与位置记忆的假设。在第二个脑代谢图的应用中，在单侧视觉刺激后，通过2-脱氧葡萄糖放射自显影法测量局部葡萄糖利用率（LGU）。我们发现，小脑小叶，尤其是在对侧，在视觉刺激时，表现出高LGU。在对侧小叶的中间三分之一，我们发现了斑块状高LGU区域，这可能对应于小脑microzones.In 1989年，正电子发射断层扫描（PET）被引入东京大学医院和放射科要求我们修改我们的PET系统的视觉刺激器。重要的是进一步发展我们的临床诊断结果。

We obtained two major results in this research project; first was to manufacture a visual stimulator and to show its effectiveness in an electrophysiological single-unit recording. Second was to apply it to the metabolic mapping of the brain.We had already shown merits of using "fractal patterns" in the research of visual memory. In this project our visual stimulator was constructed by modifying the FBX24 (Texnai) image frame memory system. The stimulator utilized the zoom, pan and scroll functions of FBX24 and succeeded in generating fractal patterns and presenting them at any position of the visual field in any size within 17msec. By using this stimulator we found that a shape-selective neural activity in the temporal cortex was highly selective for the pictorial information and was independent of the physical attributes such as size, orientation, color or position of the presented stimulus. In the hippocampus we found neuronal activity related to the place in which a stimulus was shown. This finding supports the hypothesis that the hippocampus contributes to the place memory. In the second application to metabolic mapping of the brain, local glucose utilization rates (LGU) were measured by 2-deoxyglucose autoradiography method after unilateral visual stimulation. We found that the cerebellar flocculus, especially in the contralateral side, exhibited high LGU during the visual stimulation. In the middle one-third of the contralateral flocculus we found patch-like high LGU areas, which may correspond to the cerebellar microzones.In 1989 a positron emission tomography (PET) was introduced in the Tokyo University Hospital and the Department of Radiology asked us to modify our visual stimulator for the PET system. It is important to further develop our results for a clinical diagnosis.