An old philosophical debate asks the question, how do we know that our emotions are commensurate with one another? Meaning, can we tell if my experience of joy or sorrow is similar to yours? How can we tell if we mean the same thing by the words – or not?

Philosophy has gone in two directions, roughly speaking. Either you argue that emotions are unknowable and we are essentially isolated from one another, or you come down on the side of thinking that we’re all basically the same, within broad parameters and allowing for individual differences.

The implications for public speakers are profound. If we are isolated from one another emotionally speaking, then the idea of a group experience is suspect – and a speech is a not very worthwhile way to spend time (and money). If, on the other hand, we’re basically the same, then a group experience can have lots of uses and plenty of meaning.

Now along comes research that suggests that we are indeed basically the same – that we mean the same thing and experience the same thing with our emotions. The research comes from a surprising angle.

What are the findings? Neuroscientists have trained a computer to read the neural signature of brain scans of a few basic emotions – with 90 % accuracy. In other words, solely by studying the brain scan of someone, the computer can tell if that person is experiencing, say, disgust. And how intensely they’re feeling it.

What’s even more interesting is that the computer can report how you’re doing more accurately than you can. It turns out that many people aren’t very reliable at reporting their own emotions – or the strength of them – but the computer is. As long as it can see a brain scan.

As the head researcher, Dr. Luke Chang, said, “This means that brain imaging has the potential to accurately uncover how someone is feeling without knowing anything about them other than their brain activity.

This has enormous implications for improving our understanding of how emotions are generated and regulated, which have been notoriously difficult to define and measure.”

And it resolves that old philosophical question in favor of shared group experiences – which means that not only is public speaking meaningful, but it’s also valuable. It’s an opportunity to share an emotion, a direction, an idea, widely – and thereby to change the world.

You are not alone. And that matters.