1. A friend of yours is taking a class in medical ethics. “We discussed a tough case today,” she says. “It has to do with a patient who’s been in a vegetative state for several years, and the family has to decide whether to take him off life support. The doctors say he has no awareness of himself or his environment, and he is never expected to recover. But when light is shined in his eyes, his pupils contract. That shows he can sense light, so he has to have some ability to perceive his surroundings, doesn’t he?” Without knowing any of the details of this particular case, how would you explain to your friend that a patient might be able to sense light but not perceive it? What other examples from the chapter could you use to illustrate the difference between sensation and perception?
2. In your philosophy class, the professor discusses the proposition that “perception is reality.” From the point of view of philosophy, reality is the state of things that actually exists, whereas perception is how they appear to the observer. What does psychophysics have to say about this issue? What are three ways in which sensory transduction can alter perception, causing perceptions that may differ from absolute reality?
3. A friend comes across the story of an American soldier, Leroy Petry, who received the Medal of Honor for saving the lives of two of his men. The soldiers were in a firefight in Afghanistan when a live grenade landed at their feet; Petry picked up the grenade and tried to toss it away from the others, but it exploded, destroying his right hand. According to the news report, Petry didn’t initially feel any pain; instead, he set about applying a tourniquet to his own arm while continuing to shout orders to his men as the firefight continued. “That’s amazingly heroic,” your friend says, “but that bit about not feeling the pain—