TED演讲：拥有大脑的真正原因(10)

 　　So we decided¹ to test this in the lab. Now we don't work with children, we don't work with hitting, but the concept is identical.  所以我们决定在实验室里做这个测试，好了我们不用小孩子，也不用打的，不过概念是相同的。

　　We bring in two adults. We tell them they're going to play a game.  我们找来两个成人。告诉他们来做个小游戏。

　　And so here's player one and player two sitting opposite to each other.  这里显示了玩家一和玩家二面对面坐着。

　　And the game is very simple. We started with a motor with a little lever, a little force transfuser.  游戏很简单。开始的时候这里有个电机，连着小杠杆，作为传力器。

　　And we use this motor to apply force down to player one's fingers for three seconds and then it stops.  小电机向下对玩家一的手指施力持续3秒钟后停止。

　　And that player's been told, remember the experience of that force and use your other finger to apply the same force down to the other subject's finger through a force transfuser -- and they do that.  我们告诉这名玩家一，记住这个力的感觉，再用另一个手指以同样的力，通过传力器下压玩家二的手指--玩家一这么做了。

　　And player two's been told, remember the experience of that force.  然后玩家二被告知记住这个力的感觉。

　　Use your other hand to apply the force back down.  用另一只手把同样的力施加回来。

　　And so they take it in turns to apply the force they've just experienced back and forward. 这两个玩家轮流来回施加方才所受的力。

　　But critically, they're briefed about the rules of the game in separate rooms.  不过关键的一点是这两个玩家是在不同房间里被介绍游戏规则的。

　　So they don't know the rules the other person's playing by.  所以他们互相不知道对方遵循的规则。

　　And what we've measured is the force as a function of terms.  而我们测量的是力的大小关于回合次数的函数。

　　And if we look at what we start with, a quarter of a Newton there, a number of turns, perfect would be that red line.  我们来看图，开始的时候力是四分之一牛顿，横轴是回合的次数，完美的结果应该是这条红线。

　　And what we see in all pairs of subjects is this -- a 70 percent escalation² in force on each go.  但是我们在所有实验配对中看到的都是这个--每一次施力中大小上扬70%。

　　So it really suggests, when you're doing this -- based on this study and others we've done -- that the brain is canceling the sensory³ consequences and underestimating the force it's producing.  所以确实表明，我们在运动的时候--根据这个实验和我们所做的其他实验--大脑一直在抵消感官带来的结果。

　　So it re-shows the brain makes predictions and fundamentally changes the precepts⁴.  而低估自己产生的力，所以再次说明大脑会做出预测，并且在根本上改变感知到的内容。

　　So we've made inferences, we've done predictions, now we have to generate actions.  到现在为止，我们做了推断，也做了预测，现在我们要生成动作了。

　　And what Bayes' rule says is, given my beliefs, the action should in some sense be optimal⁵. 贝叶斯法则说的是，基于置信值动作应该在某种意义上是最优的。

1 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

2 escalation   

n.扩大，增加

参考例句：

• The threat of nuclear escalation remains. 核升级的威胁仍旧存在。 来自辞典例句
• Escalation is thus an aspect of deterrence and of crisis management. 因此逐步升级是威慑和危机处理的一个方面。 来自辞典例句

3 sensory   

adj.知觉的，感觉的，知觉器官的

参考例句：

• Human powers of sensory discrimination are limited.人类感官分辨能力有限。
• The sensory system may undergo long-term adaptation in alien environments.感觉系统对陌生的环境可能经过长时期才能适应。

4 precepts   

n.规诫，戒律，箴言( precept的名词复数 )

参考例句：

• They accept the Prophet's precepts but reject some of his strictures. 他们接受先知的教训，但拒绝他的种种约束。 来自《现代英汉综合大词典》
• The legal philosopher's concern is to ascertain the true nature of all the precepts and norms. 法哲学家的兴趣在于探寻所有规范和准则的性质。 来自辞典例句

5 optimal   

adj.最适宜的；最理想的；最令人满意的

参考例句：

• What is the optimal mix of private and public property rights in natural resources?私人和国家的自然资源产权的最适宜的组合是什么？
• Optimal path planning is a key link for the sailing contest.帆船最优行驶路径规划是帆船比赛取胜的关键环节。