Anesthesia is often cited as one of the greatest advances in modern medicine. However, every once in a while, something goes wrong and a person wakes up in the middle of a procedure. The results can be deeply traumatic. The truth is, we don’t know how some anesthetic medicines work. But if we could find out, not only would patients remain safely comatose, the journalist Joshua Lang says we’d also close in on some deep questions about what it means to be conscious. Lang’s written an article about anesthesia and consciousness and he joins us Tuesday to discuss it.