共用题干
第二篇
Exercise and Brain
Just as exercise strengthens the heart and lungs,bones and muscles,it may also power up the brain.A succession of scientific studies of animals implies that physical activity has a positive effect on mental functioning.
"It's clear that the brain benefits from exercise,"says brain scientist William Greenough of the University of Illinois at Urbana-Champaign.His studies with rats have demonstrated two primary effects of activity:Vigorous physical exercise provides the brain with more fuel,and skill-based ex-ercise increases the formation of connections in the brain, which, according to the proposals of some scientists,may make the brain better able to process information.
In one experiment,laboratory rats were separated into three groups.One group was exercised by running inside an automatic wheel,a second group improved their skills in a complicated obstacle course,and a third group was inactive.
"The animals that learned to go through the obstacle course exhibited a greater number of brain connections than the animals in the exercised or inactive groups,"Greenough said."In contrast, the animals that exercised inside the automatic wheel possessed a greater density of blood vessels in the brain than did either of the other two groups of animals."
Learning a new dance step may boost the brain in the same way that learning a language can, he says.And if the dance is a good physical exercise as well,the benefits multiply.Young brains may be especially able to boost brain power through exercise,suggested another of Greenough's experiments that showed the most significant changes in the brain occurred among rats that had been exercised when very young.And while animals aren't people,he says it is logical to make the inference that an effect found in rats may also apply to humans.
Human studies have focused primarily on older adults and suggest that regular exercise can improve the speed with which the brain processes information.Measurements made by Arthur Kramer at the University of Illinois demonstrated that inactive adults,aged 63 to 82,could hit buttons faster in response to a tone after they went through a 10-week water exercise course.A corresponding control group that didn't exercise showed no improvement.
Which statement is correct according to the passage?
A:The effect of exercises found in rats can not apply to people.
B:Changes in the brain occurred among young rats are more significant than those among adult rats.
C:Regular exercise can only improve the speed with which the older adults' brain processes information.
D:The author encourages people do more skill-based exercise instead of vigorous physical exercise.