Lew H L, Slimp J, Price R, Massagli T L, Robinson L R
Department of Rehabilitation Medicine, the University of Washington School of Medicine, Seattle 98195, USA.
Am J Phys Med Rehabil. 1999 Jul-Aug;78(4):367-71. doi: 10.1097/00002060-199907000-00014.
The P300 response is a cognitive event-related potential recorded over the scalp. The tone-evoked P300 response has been used to predict outcomes of patients with brain injury. However, it may lead to false predictions because some normal people have a very small tone-evoked P300 response. It is hypothesized that speech may generate a more robust P300 response than tones. A voice-generator prototype was designed for this study. The rare speech signal was the word "mommy" in a female voice. The common signal was a 1000-Hz tone. Twenty-two normal adults (11 males, 11 females; age range, 18-60 yr) were tested for both speech-evoked and tone-evoked P300 responses. Speech-evoked P300 responses had significantly larger amplitudes (mean, 12.1 microV) than the tone-evoked responses (mean, 5.9 microV; P < 0.0001). Six subjects with brain injury were also tested using the same protocol: two subjects with severe brain injury showed no response to either stimulus. Both died within 1 wk after the testing. Although two subjects with moderate brain injury could not complete the testing because of agitated behavior, two other subjects with mild traumatic brain injury showed a larger speech-evoked than tone-evoked P300 response. The speech-evoked P300 response may be promising in predicting outcomes of patients with brain injury.
P300反应是一种记录在头皮上的与认知事件相关的电位。音调诱发的P300反应已被用于预测脑损伤患者的预后。然而，它可能会导致错误的预测，因为一些正常人的音调诱发P300反应非常小。据推测，言语可能比音调产生更强健的P300反应。本研究设计了一种语音发生器原型。罕见的语音信号是女性声音说出的“妈妈”一词。常见信号是1000赫兹的音调。对22名正常成年人（11名男性，11名女性；年龄范围18 - 60岁）进行了言语诱发和音调诱发P300反应测试。言语诱发的P300反应的振幅（平均12.1微伏）显著大于音调诱发的反应（平均5.9微伏；P < 0.0001）。还使用相同方案对6名脑损伤患者进行了测试：两名重度脑损伤患者对两种刺激均无反应。两人在测试后1周内死亡。尽管两名中度脑损伤患者因烦躁行为无法完成测试，但另外两名轻度创伤性脑损伤患者的言语诱发P300反应大于音调诱发的反应。言语诱发的P300反应在预测脑损伤患者的预后方面可能很有前景。
