麻醉药帮助我们理解什么是意识_BEC初级作文

麻醉药帮助我们理解什么是意识

Lacking a way to measure consciousness directly, anesthesiologists monitor for proxies of it — the presence of certain types of brain waves, physical responses and sensitivity to pain — and adjust the dosage if they arise. To improve on this method, neuroscientists are searching for what they call neural correlates of consciousness — changes in brain function as a person transitions from being apparently conscious to apparently unconscious. The more they know about these, the better they hope to understand what consciousness is.

由于无法直接对意识加以测量，麻醉师们只好退而求其次，监测意识的替代物——特定类型的脑电波、生理反应和疼痛敏感度的存在情况，并在上述指标升高时增加麻醉剂量。此外，为了改善这一方法，神经科学家正试图寻找“意识的神经机制”(neural correlates of consciousness)，即，人在从明显的意识知觉状态转变为明显无意识状态的过程中脑功能的改变。他们认为，对此了解得越深入，就越有希望解开意识之谜。

Michael Alkire, associate professor of anesthesiology at the University of California, Irvine, was one of the first people involved in the search for neural correlates of consciousness, back in the 1990s. He's particularly excited now about a study published in August by an international team of researchers based at the University of S?o Paulo and the University of Wisconsin, Madison. They compared the brain activity of patients from the full spectrum of consciousness — awake, asleep, drugged with anesthetics, in comas or suffering from "locked-in syndrome," in which the body appears trapped in a comalike state but the brain is active and aware. The researchers stimulated these subjects' brains with a magnetic field and used EEG to trace the pulse's path. The brains we might think of as conscious and those we think of as unconscious reacted to the stimulus in distinct ways. "If the patient is awake, the electrical ‘ping' can travel all around the brain," Alkire said. "But if they're unconscious, the ‘ping'tends to stay localized and just fades away like a sonar blip."