Effect of level of consciousness on blood flow and oxygen consumption in the primary sensory area during sensory stimulation

我们研究了大脑在清醒和睡眠时对听觉刺激的反应。首先，我们探讨了在磁共振成像系统中获取脑电信号的方法。虽然脉冲伪影发生了迁移，但仍能得到可用于睡眠分期的心电图。经过初步的实验，我们测量了信号的变化与功能磁共振成像在六个睡眠剥夺男性志愿者。他们的年龄在25至44岁之间。他们都没有睡眠，听力或神经问题。在施加电极后，他们仰卧着，戴着耳机进行听觉刺激。测量采用1.5 T MR系统。每12秒进行一次MR图像采集。听觉刺激每36秒交替一次。感兴趣区设置为双侧横回，其中存在初级听觉皮层。结果显示，睡眠时的信号变化百分比、激活像素数和最大Z分数均显著低于清醒时。

We investigated how brain responded to auditory stimuli during wakefulness and sleep. First, we explored the methods to obtain electroencephalogram (ECG) in magnetic resonance (MR) imaging system. Although pulse artifact migrated, ECG which could be used to detect sleep stages was obtained. After preliminary experiments, we measured signal change with functional magnetic resonance imaging in six sleep deprived male volunteers. They ranged in age between 25 to 44 years. None of them had sleep, hearing, or neurological problems. After applying electrodes, they laid supine with headphones for auditory stimulation. Measurement was performed with 1.5-T MR system. MR image acquisition was performed ever 12 seconds. Auditory stimulus was alternated every 36 seconds. Region of interest was set to be bilateral transverse gyri, in which primary auditory cortex exists. Results showed that percentage signal change, the number of activated pixels, and the maximal Z-score during sleep were significantly less than those during wakefulness.