Abstract
Based on the recent reports that the changes of the cerebral ultrasonic attenuation (CUSA) can be an indicator of the cerebral circulation under certain conditions, the following two experiments were carried out to clarify the relationship between nervous activities and the cerebral circulation. The examinees were healthy male students, 22 in experiment 1 and 15 in experiment 2.
1. Changes of CUSA were observed under exposure to sonic boom and gradually increasing noise. The latter caused no change of CUSA, while the sonic boom resulted in a characteristic pattern change of CUSA with an initial increase and its early restoration to the original state.
From these observations it is assumed that a strong sensory stimulation caused a temporary decrease of the cerebral circulation. This is restored quickly by autoregulation of the cerebral circulation and the movement in body circulation.
2. The change of CUSA due to postural change correlated significantly with the CPT-swing degree.
These observations reveal that the homeostasis in the circulatory system appears to be parallel for both tests.
