单选题 Exciting new research indicates that growing older might not necessarily mean growing mentally slower. New studies are providing breakthroughs in our understanding of how aging affects memory, language, and other cognitive functions. This information could provide tools for lessening or even averting some loss in brain functioning often associated with old age.
If science can help older citizens retain their mental abilities longer, then the whole nation would benefit. That's why it is so important for research on the aging mind to flourish. The government should make studying neural health, the role of life experiences in shaping the brain, and the structure of the aging mind—key priorities in these years. And the National Institute on Aging should undertake major research initiatives in these areas to expand the scientific basis for understanding and promoting healthy mental aging.
Revolutionary advances in neuron-science, behavioral science, and the science of learning have opened the door for the development of new techniques and technologies that can preserve mental sharpness in older people. These might be as novel as transplanting genetically engineered cells to replace disfunctional neurons or as familiar as engaging in stimulating intellectual and physical activities.
As many jokes about losing brain cells illustrate, it has long been thought that age-related decline in cognitive abilities is a result of diminishing neurons and synapses. But scientists have discovered that as people grow old, a drop in certain mental abilities may have more to do with changes in the health of the nervous system. For example, the mild loss of memory that is often associated with growing old may be linked to biochemical shifts in neurons rather than to actual loss of brain cells. Research aiming at identifying the mechanisms that maintain or impair neural health is critical for advancing our knowledge of aging.
In addition, exciting studies under way around the country are exploring the degree to which older people can benefit from certain kinds of mental practice. We are only beginning to understand the pliability of cognitive functioning in people who are already old, but the promise of finding ways to maintain abilities is very real. For example, studies indicate that our life experiences can bring about lasting changes in our brains that shape how we age. Aging people with college or postgraduate degrees, for instance, generally have better cognitive functioning, such as language and reasoning than those with less education. And better-educated people who reach their 80s—when much of the decline in brain functioning typically occurs—experience far fewer cognitive problems than their less-educated peers. Scientists believe that formal education and professional training lead to more dense and complex associations among neurons that maintain functions even when those associations weaken.

【正确答案】 A

【答案解析】推理题。本题定位到首段内容“Exciting new research indicates that growing older might not necessarily mean growing mentally slower.”新的研究表明衰老并不一定意味着思维速度减慢。换句话说，过去的人们一直认为，衰老就会引起思维速度减慢。因此，选项A正确。一项令人兴奋的新研究表明，年龄的增长并不一定意味着思维速度减慢。最新的研究在我们理解衰老如何影响记忆、语言和其他认知功能方面，给我们提供了重要的新发现。这一信息可以提供缓解甚至避免常与年老有关系的脑功能缺损的方法。如果科学能够帮助年长的公民更长久地保留心智能力，那么整个国家会受益颇多。那就是研究让老化的头脑活跃起来是如此重要的原因。政府应该努力研究神经健康，人生的经历在塑造大脑上所起的作用，以及老年人的头脑结构——这都是近几年最重要的事情。同时，为了扩大理解和提升健康心理老化问题的科学根据，国家衰老研究所在这些领域应该率先承担主要研究。在神经科学、行为科学以及学习科学上的革命性突破已经为新技术的发展打开了大门，这些新技术能使老年人在精神上保持敏锐度。这些可能会和用移植基因工程细胞来取代不健全的神经元一样新奇，或是和从事刺激脑力和体力的活动一样常见。就如同有关丢失脑细胞的一些笑话中所说的那样，长期以来人们一直认为与年龄有关的认知力的下降是由神经元和突触的递减所造成的。但是科学家们发现随着人们逐渐衰老，某些智力能力的丧失与神经系统健康受损有更大关系。比如说，通常跟年龄增长有关的轻微的记忆缺失可能与神经元的生化变化有关，而非脑细胞的实际缺损。鉴别保持或削弱神经系统健康的机制的研究对于提高我们对衰老的认识有至关重要的影响。此外，令人兴奋的研究正在全国各地开展，研究探索老年人能从某种智力练习中获益的程度。我们现在才开始了解老年人认知功能的易适应性，但是找到保持智力的方法还是很有可能的。比如说，研究表明，我们的生活经历能给改变我们年龄的大脑带来持久的变化。再比如，大学或研究生毕业的老年人跟那些受到较少教育的人相比通常会有更好的认知功能，比如语言和推理能力。而当那些受过良好教育的人到80岁——大部分的脑功能开始衰退的时候——与比他们受教育少的同龄人相比，他们会经受更少的认知问题。科学家们相信正规教育和专业培训会在神经元中产生更密致复杂的联系，即使那些联系会削弱，功能还是会继续维持。