回想一下你上次聆听某人发表演讲或任何正式陈述的情形。它也许太长了，以至于你被各种数据搞得头昏脑胀，甚或干脆不理会演讲者。如果演讲者使用了PPT文档，那么每张幻灯片很可能塞入了至少40个单词或数字，但你现在或许只记得一丁点内容。

相当平淡，是吧？《像TED那样演讲：全球顶级人才九大演讲秘诀》(Talk Like TED: 9 Public-Speaking Secrets of The World's Best Minds)一书以流畅的文笔审视了为什么TED演讲如此生动，如此引人入胜。出版方有意安排在今年3月份发行此书，以庆贺如今已成为经典的TED大会成立30周年。这部著作借鉴当代脑科学解释了什么样的演讲能够说服听众、鼓舞听众，什么样的演讲无法产生这种效果。

作者卡迈恩•加洛还研究了500多场最受欢迎的TED演讲（到目前为止，TED大会已组织了大约1,500场演讲），还采访了许多演讲嘉宾。

他挖出了不少令人吃惊的演讲策略。例如，每场TED演讲都被限制在18分钟以内。听起来太过短暂，似乎无法传达足够多讯息。然而，TED大会策办人克里斯•安德森决议推行这项时间限制规则，因为“这个时间长度足够庄重，同时又足够短，能够吸引人们的注意力。通过迫使那些习惯于滔滔不绝讲上45分钟的嘉宾把演讲时间压缩至18分钟，你就可以让他们认真思考他们真正想说的话，”他对加洛说。此外，安德森说，如果你希望你的讯息像病毒般扩散，这也是一个完美的时间长度。

最近的神经科学研究说明了为什么这项时间限制产生如此好的效果：聆听陈述的人们往往会存储相关数据，以备未来检索之用，而太多的信息会导致“认知超负荷”，进而推升听众的焦虑度。它意味着，如果你说个没完没了，听众就会开始抗拒你。更糟糕的是，他们不会记得你努力希望传递的信息点，甚至可能一个都记不住。

“爱因斯坦曾经说过，‘要是你不能言简意赅地解释某种理论，那就说明你自己都还没有理解透彻，’”加罗写道。他还举例说，物理学家或许会大加赞赏天文学家大卫•克里斯蒂安在2011年TED大会上发表的演讲。克里斯蒂安在这个演讲中完整地讲述了宇宙史及地球在宇宙的地位，整场演讲用时只有17分40秒。

如何把一个复杂的陈述压缩至18分钟左右？加洛就这个问题提供了一些小建议，其中包括他所称的“三的法则”。具体说就是，把大量观点高度浓缩为三大要点。TED大会上的许多演讲高手就是这样做的。他还指出，即使一篇演讲无法提炼到这样的程度，单是这番努力也一定能改善演讲的效果：“仅仅通过这番提炼，你就可以大大增强陈述的创造性和影响力。”

另一个建议与PPT文档有关。“TED大会象征着我们所知的PPT文档正走向终结，”加洛写道。他随后又马上补充说，作为工具的PowerPoint本身并没有什么错，但大多数演讲者为他们的幻灯片塞进了太多的单词（平均40个）和数字，让这种工具不经意间带来了消极影响。

最吸引人的TED演讲为我们提供了一个补救策略：如果你必须使用幻灯片，务必记得要大量运用图像资源。这种做法同样有科学依据，它就是研究人员所称的“图优效应”(Picture Superiority Effect)：听到或读到一组事实三天后，大多数人会记得大约10%的信息。而添加一张照片或图片后，记忆率将跃升至65%。

华盛顿大学医学院(University of Washington School of Medicine)分子生物学家约翰•梅迪纳主持的研究发现，几天后，人们能够回想起超过2,500张图片，准确率至少达到90%；一年后的准确率依然保持在63%左右。

梅迪纳的研究表明，这个结果“完胜”印刷品和演讲的记忆效果（由同一组受试者测试）。任何一位希望自己的思想被听众铭记在心的演讲者或许都应该记住这一点。（财富中文网）

译者：叶寒

Think about the last time you heard someone give a speech, or any formal presentation. Maybe it was so long that you were either overwhelmed with data, or you just tuned the speaker out. If PowerPoint was involved, each slide was probably loaded with at least 40 words or figures, and odds are that you don't remember more than a tiny bit of what they were supposed to show.

Pretty uninspiring, huh? Talk Like TED: 9 Public-Speaking Secrets of The World's Best Mindsexamines why in prose that's as lively and appealing as, well, a TED talk. Timed to coincide with the 30th anniversary in March of those now-legendary TED conferences, the book draws on current brain science to explain what wins over, and fires up, an audience -- and what doesn't. Author Carmine Gallo also studied more than 500 of the most popular TED speeches (there have been about 1,500 so far) and interviewed scores of the people who gave them.

Much of what he found out is surprising. Consider, for instance, the fact that each TED talk is limited to 18 minutes. That might sound too short to convey much. Yet TED curator Chris Anderson imposed the time limit, he told Gallo, because it's "long enough to be serious and short enough to hold people's attention ... By forcing speakers who are used to going on for 45 minutes to bring it down to 18, you get them to think about what they really want to say." It's also the perfect length if you want your message to go viral, Anderson says.

Recent neuroscience shows why the time limit works so well: People listening to a presentation are storing data for retrieval in the future, and too much information leads to "cognitive overload," which gives rise to elevated levels of anxiety -- meaning that, if you go on and on, your audience will start to resist you. Even worse, they won't recall a single point you were trying to make.

"Albert Einstein once said, 'If you can't explain it simply, you don't understand it well enough,'" Gallo writes, adding that the physicist would have applauded astronomer David Christian who, at TED in 2011, narrated the complete history of the universe -- and Earth's place in it -- in 17 minutes and 40 seconds.

Gallo offers some tips on how to boil a complex presentation down to 18 minutes or so, including what he calls the "rule of three," or condensing a plethora of ideas into three main points, as many top TED talkers do. He also notes that, even if a speech just can't be squeezed down that far, the effort alone is bound to improve it: "Your presentation will be far more creative and impactful simply by going through the exercise."

Then there's PowerPoint. "TED represents the end of PowerPoint as we know it," writes Gallo. He hastens to add that there's nothing wrong with PowerPoint as a tool, but that most speakers unwittingly make it work against them by cluttering up their slides with way too many words (40, on average) and numbers.

The remedy for that, based on the most riveting TED talks: If you must use slides, fill them with a lot more images. Once again, research backs this up, with something academics call the Picture Superiority Effect: Three days after hearing or reading a set of facts, most people will remember about 10% of the information. Add a photo or a drawing, and recall jumps to 65%.

One study, by molecular biologist John Medina at the University of Washington School of Medicine, found that not only could people recall more than 2,500 pictures with at least 90% accuracy several days later, but accuracy a whole year afterward was still at about 63%.

That result "demolishes" print and speech, both of which were tested on the same group of subjects, Medina's study indicated, which is something worth bearing in mind for anybody hoping that his or her ideas will be remembered.