As we age, our ability to think and remember stars to deteriorate. It is normal for old age to be associated with gradual decline in memory and brain mass. 【小题1】 Some of us have brains that age more slowly. Super-agers are people over the age of 80 who have the brain structures and abilities of much younger people. Eighty-seven-year-old Bill Gurolnick is such a super-ager.

Scientists know that parts of the brain decrease in size with age. But in super-agers that process is much slower. Emily Rogalski is a neuro-scientist at Northwestern University's Feinberg School of Medicine, in Chicago, Illinois. In a recent study, she showed that super-agers have young brains. The area of the brain responsible for attention and memory -- the cortex (脑皮层)— was shown to be thicker in super-agers.

"When we look at the cortex of their brain, we see that, on average, it looks more like a 50-year-old brain than it looks like an average 80-year-old brain."

【小题2】 These large brain cells appear to be involved with social-emotional communication. But their exact purpose is still a mystery. Scientists writing for Smithsonian magazine also call them spindle neurons (纺锤体神经元), and say they are "brain cells for socializing."

Several factors affect how our brains age. Scientists say super-agers have several things in common, including an active lifestyle. Many travel and play sports. They are often big readers. 【小题3】.

Super-agers also seem to have certain common personality traits. Rogalski says they are, for the most part, known for their optimism, resilience and perseverance. Growing old, she adds, does not have to be depressing and sad. "Perhaps, if we expected a bit better from ourselves, then we would understand that not all aging is doom and gloom."

【小题4】 That they are special and few. She says she wants to find out the reasons Gurolnick's mind is working so well and not aging as quickly as most.

Gurolnick's own father was diagnosed with Alzheimer's in his fifties Solving this mystery, Rogalski says, may help those who suffer from brain diseases such as Alzheimer's.

"We think if we can understand the factors contributing to super-aging, it may offer new hypotheses and new ways to explore the challenges in Alzheimer's disease."