大脑中那些神经的连接构成亿万世界_BEC初级作文

大脑中那些神经的连接构成亿万世界

在创造思潮难抑之时，维尔马的神经回路图会即时记录下大脑的情况。据2003年发表在《比较神经外科学杂志》(Journal of Comparative Neurology)上的一项丹麦研究表明，从婴儿时期开始，人脑通常就会以每分钟50万个的速度长出神经元，并以每秒钟200万次的速度伸展、形成连接。到了五岁的时候，大脑的尺寸一般会长到成年人脑的90%。到了20岁的时候，平均而言，大脑中会布满长达109,000英里（约合175,418千米）的白质组织纤维。

Spurred by the effects of diet, experience and biochemistry, neurons and synapses are ruthlessly pruned, starting in childhood. The winnowing continues in fits and starts throughout adolescence, then picks up again in middle age. 'In childhood, we did not see much difference' between male and female, Dr. Verma said. 'Most of the changes we see start happening in adolescence. That is when most of the male-female differences come about.'

在饮食习惯、生活经历和生物化学的影响刺激下，神经元与突触从童年时期就开始被无情地修剪。这场筛选一阵一阵地继续，然后开始贯穿整个青春期。维尔马说：“童年时期，我们在男孩女孩身上看不到太多的差别。我们看到的大多数变化都发生在青春期。也就是那个时候，男女之间的大多数差别显现出来了。”

Broadly speaking, women in their 20s had more connections between the two brain hemispheres while men of the same age had more connective fibers within each hemisphere. 'Women are mostly better connected left-to-right and right-to-left across the two brain hemispheres,' Dr. Verma said. 'Men are better connected within each hemisphere and from back-to-front.'