Imagine you and I are chatting in your fourth-floor conference room when the fire alarm goes off. We evacuate the building, and watch smoke pour from a set of second-floor windows as fire trucks arrive.

A few days later, we're chatting in my conference room when the fire alarm goes off. Somehow you and I have very different emotional reactions. Me? The fire alarm sparks instant terror; we could have been trapped in your building the other day.

You, on the other hand, see the fire alarm as a positive. Hearing the fire alarm means we won't get trapped in my building. In fact, you view fire alarms as a good thing, a system that works.

Same event, two very different reactions. 

Neuroscientists call the process of linking feelings with a memory "valence assignment." Once we experience something, our brains associate it with a positive or negative feeling -- a valence -- so we know whether to seek or avoid it in the future. 

For you, a fire alarm is a good memory; we escaped unharmed. For me, it's a bad memory; we could have gotten trapped.

How that happens -- at a cellular level -- is unclear. Scientists know that different sets of neurons are activated when a valence is positive, and others when a valence is negative. 

"We found these two pathways -- analogous to railroad tracks -- that were leading to positive and negative valence," says professor Kay Tye, "but we still didn't know what signal was acting as the switch operator to direct which track should be used at any given time." 

So Tye and her colleagues at the Salk Institute used gene editing to selectively remove the gene for neurotensin, a signaling molecule, from the brain cells of mice. Without neurotensin, those mice could no longer assign positive valence to a memory. 

It turns out lacking neurotensin didn't affect negative valence, though. In fact, the mice got even better at assigning negative valence. The neurons associated with negative valence stay switched on until neurotensin is released. 

Which makes sense. After all, fear is a survival instinct. Avoiding dangerous situations helped keep our ancestors alive. (Think of it as your brain's way of saying, "Let's assume this is bad until I know for sure it's good.")

Then the researchers introduced high levels of neurotensin and found they could promote reward learning, think positive associations, and further dampen negative valence. According to Tye, "We can actually manipulate this switch to turn on positive or negative learning."

All of which sounds good if we have a steady supply of neurotensin on hand. (Which, of course, we don't.) But there are ways to game the neurochemical system.

One way?

Reframe a negative experience.

Say a presentation fell flat.

Take a moment to think things through. Yeah, it went poorly. But that's because you weren't prepared. Next time, you'll know what to do. Or it's because you didn't read the room. Next time you'll build in a few "take a breath" moments so you can adjust, in the moment, to how your presentation is being received. Or because you created the right presentation for the wrong audience. Next time you'll determine your audience's needs before you even start to craft your presentation. 

Mentally assigning positive outcomes -- for example, "Here's what I learned" -- to a negative situation will help you assign a positive valence to that experience, and be much more likely to seek out that experience again.

Or better deal with the situation if it recurs. 

Prime your self-worth pump.

Research shows mentally taking a step back to focus on your overall sense of self-worth, before you do something difficult, will minimize your physiological response to failure if it doesn't go well. 

One more?

Focus on the granular emotion. 

Unlike a general feeling, like feeling stressed, a granular emotion is a specific feeling like fear, worry, or anxiety. (On the flip side, compared to feeling happy, a granular emotion might be pleased, delighted, or excited.)

The more general the feeling, the more likely you are to assign a negative valence to the situation that sparked the emotion.

Dying in that (hypothetical) first fire was highly unlikely. The building had a number of exit points and stairways. It had fire escapes on opposite sides of the building, accessible from the roof. Plus I now (again, theoretically) have experience exiting a building during a fire. Getting the opportunity, because it is an opportunity, to think the situation through and consider what could have happened, and what I would have done in response -- that's a good thing. That means I will be better prepared the next time. 

All of which helps me assign a more positive valence to a fire alarm.

And hopefully respond better.

Which, when you boil things down, is the point. We can't always control what happens. But we can always control how we respond.

And the more positive your valence assignment to situations, especially to seemingly uncomfortable or challenging situations the better you'll be able to respond.