There's a scientific reason why you couldn't stop listening to or considering what Michelle Obama was saying when she spoke at this week's Democratic National Convention.

If you want to be an influential leader and deliver a highly regarded, respected speech, you'd do well to take note and make use of this scientific secret: people make decisions for emotional reasons, and justify them with rational ones.

While any leader can inflame an audience by recklessly triggering base emotions of rage and humiliation, Michelle displays the art of evoking the generative emotions of hope and optimism in her audience.

Her approach is beguilingly simple, yet grounded in brain science: start with an image that evokes an emotion, and then back it up with the logical implication. Your audiences' decisions become a natural by-product. 

Science at work

Consider the following part of Michelle's speech. She created an image, evoking emotion in her audience--and then justified what she said with logic. 

"I wake up every morning in a house that was built by slaves and I watch my daughters:  two beautiful and intelligent black young women, playing with their dogs on the White House lawn. And because of Hilary Clinton, my daughters and all our sons and daughters now take for granted that a woman can be president of the United States."

Now, take another look at how skillfully Michelle pulls this technique off--this time with a sobering image of a leader capable of triggering Armageddon: 

"When you have the nuclear codes at your fingertips, and the military at your command, you can't make snap decisions, you can't have a thin skin, or a tendency to lash out. You need to be steady and measured and well-informed."

No need to name Trump. No need to call anyone rash or reckless. 

In one artful stroke, Michelle Obama plants an image in the minds of her audience--evoking an emotion of grave concern. The audience instantly sees the logical implications and the decision is as instant as it is emphatic: "Trump can never, ever, sit in that seat of power. Hilary has to."

Mission accomplished, and no mud stains on the hands.

Welcome to the feelings economy

Maybe you believe reason is in the driver's seat when it comes to decision-making-- that emotion sits quietly in the back, and offers a tiny opinion here and there. 

Nothing could be further from the truth.

Science reveals that when it comes to how we make decisions, emotion is in the driver's seat in ways you'd never imagine. 

It's not that reason doesn't weigh in. It clearly does; but reason simply defends the conclusion that emotion has already decided. 

In fact, research shows that as you make a decision, the choice-making area of your brain is activated before you're even aware you've made a choice!

The inner arbiter

What if surgeons did an emotion-ectomy--that is, they removed the emotional, fanciful, frivolous, illogical part of your brain? 

If you could make choices based on cold, calculated reason alone, would you be a better decision-maker? If, like many, you thought the answer was "yes", you'd be wrong. 

Neuroscientist Antonio Damasio works with patients who have sustained damage to their ventromedial prefrontal cortex. When this emotional center of the brain fails to function, it produces a surprising outcome: patients are incapable of making even the simplest of decisions.

Yes, the rational part our brain is a powerhouse when it comes to synthesizing and processing bits of information. But it relies heavily on emotion to be its arbiter.

In fact, Damasio says that without emotion, we are left continuously thinking of alternatives, and giving equal weight to each one regardless of relevance.

Put this science to work for yourself

It is highly likely you're forgetting this dynamic when you try to influence people. 

I frequently witness business leaders negotiating, delivering speeches, coaching employees and making pitches around boardroom tables. In almost every case, the message is painstakingly crafted to appeal to the logic and intellect of the audience--but it misses emotions entirely.

The next time you need to influence a group of people, take time to identify the emotion that matters most to them--and then create an image that will evoke that emotion. By creating an image that will evoke that emotion, you'll be influencing their decision.

Add just enough logic to help them rationalize what they already feel, and--just like Michelle Obama--you will make it easy for your audience to decide in your favor.