2008 年 26 巻 2 号 p. 194-200
In this paper I review infants' psychophysics experimental studies. And I show the infants' brain activity studies. The first experimental study examined infants' brain activity in response to upright and inverted faces using near infrared spectroscopy (NIRS), which can non-invasively record hemodynamic changes of the brain. We measured changes in cerebral oxygenation in ten 5-8-month-olds' left and right lateral areas while they were looking at upright and inverted faces. This is the first evidence showing that there is an inter-hemispheric difference on the effect of face inversion in the infant brain using a hemodynamic method. The second study was to examine whether a developmental difference occurs in brain activity when infants look at frontal and profile views. We compared NIRS results in 5- and 8-month-old infants, while they were looking at frontal and profile views and objects. We found that the concentration of oxy-Hb and total-Hb in the 5-month-old group increased for only frontal views in the right temporal regions. In contrast, the 8-month-old group increased for both frontal and profile views in the right temporal regions.