Losing your ability to think and remember is pretty scary. We know the risk of dementia (痴呆) increases with age. But if you have memory slips, you probably needn’t worry. There are pretty clear differences between signs of dementia and age-related memory loss.

    After age 50, it’s quite common to have trouble remembering the names of people, places and thing quickly, says Dr. Kirk Daffner of Brigham and Woman’s Hospital in Boston.

    The brain ages just like the rest of the body. Certain parts shrink, especially areas in the brain that are important to learning, memory and planning. Changes in brain cells can affect communication between different regions of the brain. And blood flow can be reduced as blood vessels narrow.

    Forgetting the name of an actor in a favorite movie, for example, is nothing to worry about. But if you forget the plot of the movie or don’t remember even seeing it, that’s far more concerning, Daffner says.

    When you forget entire experiences, he says, that’s “a red flag that something more serious may be involved.” Forgetting how to operate a familiar object like a microwave oven, or forgetting how to drive to the house of a friend you’ve visited many times before can also be signs of something going wrong.

    But even then, Daffner says, people shouldn’t panic. There are many things that can cause confusion and memory loss, including health problems like temporary stoppage of breathing during sleep, high blood pressure, or depression, as well as medications （药物） like antidepressants.

    You don’t have to figure this out on your own. Daffner suggests going to your doctor to check on medications, health problems and other issues that could be affecting memory. And the best defense against memory loss is to try to prevent it by building up your brain’s cognitive （认知的) reserve, Daffner says.

    “Read books, go to movies, take on new hobbies or activities that force one to think in novel ways,” he says. In other words, keep your brain busy and working. And also get physically active, because exercise is a known brain booster.

49. What should people do when signs of serious memory loss show up?

（当出现严重的记忆丧失的迹象时，人们应该做些什么？）

A) Check the brain’s cognitive reserve.（检查大脑的认知储备。）

B) Turn to a professional for assistance.（向专业人士寻求帮助。）

C) Stop medications affecting memory.（停用影响记忆力的药物。）

D) Exercise to improve their well-being.（通过锻炼提升幸福感。）

解析：B。首先在题目中找到定位词signs of serious memory，定位到第五段结尾，继续看第六段。该段指出，记忆力丧失可能是由睡眠中的呼吸暂停，高血压，抑郁以及药物等原因引起的。并未指出措施。第七段指出，Daffner建议去看医生，检查药物、健康问题或其他可能影响记忆力的问题。最好的办法是强化认知储备。可见当发生严重记忆丧失时应该看医生，故B选项为正确答案。A选项中check与原文中的build up相悖，故错误。原文中只提及药物可能影响记忆力，需要医生检查，并未提到停用，故C选项那个错误。D选项并未提及。