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1、Unit3 A Pill To Forget?If there were something you could take after experiencing a painful or traumatic event that would permanently weaken your memory of what had just happened, would you take it? As correspondent Lesley Stahl first reported last fall, its an idea that may not be so far off, and th
2、at has some critics alarmed, and some trauma victims filled with hope.I couldnt get my body to stop shaking. I was trembling, constantly trembling. Memories of it would just come back, reoccurring over and over and over, subway conductor Beatriz Arguedas recalls. A year ago September, Beatriz was dr
3、iving her normal route on the Red Line in Boston when one of her worst fears came to pass: Upon entering one of the busiest stations, a man jumped in front of my train, to commit suicide, she explains.Beatriz saw the man jump. We sort of made eye contact and then I felt the thud from him hitting the
4、 train and then the crackling sound underneath the train and, then, of course, my heart starts thumping, she recalls.She came into our emergency room afterwards, very upset. No physical injury. Entirely a psychological trauma, says Dr. Roger Pitman, a psychiatrist at Harvard Medical School who has s
5、tudied and treated patients with post-traumatic stress disorder, or PTSD, for 25 years.Theyre caught up so much with this past event that its constantly in their mind, Pitman explains. Theyre living it over and over and over as if its happening again. And they just cant get involved in real life.Whe
6、n Beatriz arrived in the emergency room, Pitman enrolled her in an experimental study of a drug called propranolol, a medication commonly used for high blood pressure . and unofficially for stage fright. Pitman thought it might do something almost magical trick Beatrizs brain into making a weaker me
7、mory of the event she had just experienced. In the study, which is still under way, half the subjects get propranolol; half get a placebo.Asked whether he knows if Beatriz got the drug or the placebo, Dr. Pitman says he has no idea and neither does she, and that the research team wont know for anoth
8、er two years.If Pitman is right, the results could fundamentally change the way accident victims, rape victims, even soldiers are treated after they experience trauma. The story begins with some surprising discoveries about memory. It turns out our memories are sort of like Jello they take time to s
9、olidify in our brains. And while theyre setting, its possible to make them stronger or weaker. It all depends on the stress hormone adrenaline.The man who discovered this is James McGaugh, a professor of neurobiology at the University of California, Irvine.McGaugh studies memory in rats, and he invi
10、ted Stahl to watch the making of a rat memory in this case how a rat whos never been in this tank of water before learns how to find a clear plastic platform just below the surface.Hell swim around randomly, McGaugh explains. The rat cannot see the platform, since his eyes are on the top of his head
11、.The rat will swim around the edge for a long time, until eventually he ventures out and by chance bumps into the platform. The next day, hell find the platform a little bit faster.But another rat, who had learned where the platform was the day prior, and then received a shot of adrenaline immediate
12、ly afterwards, today swam instantly to the platform.Adrenaline actually made this rats brain remember better, and McGaugh believes the same thing happens in people. Suppose I said to you, You know, Ive watched your programs a lot over the years, and although it pains me to have to tell you this, I t
13、hink youre one of worst people Ive ever seen on now dont take it, dont take it personally, McGaugh says.So, my stress system would go into overdrive, no question, Stahl says.Even with my telling you that its not true, theres nothing to keep you from blushing, from feeling warm all over, McGaugh poin
14、ts out. Thats the adrenaline. And I dare say that youre gonna remember my having said that long after youve forgotten the other details of our discussion here. I guarantee it.McGaugh says thats why we remember important and emotional events in our lives more than regular day-to-day experiences. The
15、next step in his research was to see what would happen when adrenaline was blocked; he started experimenting with propranolol.Propranolol sits on that nerve cell and blocks it, so that, think of this as being a key, and this is a lock, the hole in the lock is blocked because of propranolol sitting t
16、here. So adrenaline can be present, but it cant do its job, McGaugh explains.McGaugh showed Stahl a third rat that had learned where the platform was on the previous day and then received an injection of propranolol. The next day, the rat swam around the edge, as if he had forgotten there ever was a platform out there. Across the country at Harvard, Roger Pitman read McGaughs studies and
