Study on the effect of mastication on memories and leaning-A possibility of trigger factor of dementia-

近年来，有研究报道咀嚼功能障碍可能是痴呆的诱发因素之一。然而，关于咀嚼运动与认知功能关系的研究却很少。本研究的目的是探讨咀嚼与血流动力学之间的关系，这是我们的健康保健和预防某些神经系统疾病的第一步。首先，为了选择性地监测脑灌注，我们研究了近红外光谱（NIRS）测量的人头部光信号的一些特性，它在一些方面优于其他方法，例如，坐在座位上的测量。我们阐明了近红外光谱的有用性和局限性其次，我们使用NIRS检测了咀嚼和认知任务引起的Hb浓度变化。通过咀嚼，颞区的oxy-Hb增加（Brodmann 'sArea 9和46），而顶叶区则减少。观察到额叶和顶叶区域的氧合血红蛋白减少。我们可以假设这两种任务的激活区域有相似之处。

Recently, some researchers have reported the possibility that impairment of ability for mastication was one of the trigger factors of dementia. There are, however, only a few studies on the relationship between mastication and cognitive function. The aim of this study is to investigate the relationship between mastication and hemodynamics, which is the first step toward our health care and the prevention of some neurological diseases.First, for selective monitoring of the cerebral perfusion, we studied some characteristics of optical signals measured from the human head by near-infrared spectroscopy(NIRS), which has some advantages over other methods in terms of, for example, the measurement under sitting on the seat. We clarified the usefulness and limitations of the NIRS(time-resolved spectroscopic method) for monitoring of cerebral hemodynamics.Next, we examined Hb concentration changes evoked by chewing and cognitive tasks using NIRS By chewing, oxy-Hb increased in the temporal area(Brodmann's Area 9 and 46) and decreased in the region of parietal By doing verbal fluency task, decreases of oxy-Hb in the regions of the frontal and parietal were observed. We can suppose that there is a similarity of activation area between the two tasks.