Here is the full transcript of researcher and neuroscientist Amishi Jha’s TEDx Talk: Taming Your Wandering Mind at TEDxCoconutGrove conference.
Consider the following statement: Human beings only use ten percent of their brain capacity. Well, as a neuroscientist, I can tell you that while Morgan Freeman delivered this line with the gravitas that makes him a great actor, this statement is entirely false.
The truth is, human beings use 100 percent of their brain capacity. The brain is a highly efficient, energy-demanding organ that gets fully utilized. And, even though it is at full capacity being used, it suffers from a problem of information overload. There’s far too much in the environment than it can fully process. So to solve this problem of overload, evolution devised a solution, which is the brain’s attention system.
Attention allows us to notice, select and direct the brain’s computational resources to a subset of all that’s available. We can think of attention as the leader of the brain. Wherever attention goes, the rest of the brain follows. In some sense, it’s your brain’s boss.
And over the last 15 years, I’ve been studying the human brain’s attention system. In all of our studies, I’ve been very interested in one question: If it is indeed the case that our attention is the brain’s boss, is it a good boss? Does it actually guide us well? And to dig in on this big question, I wanted to know three things.
First, how does attention control our perception? Second, why does it fail us, often leaving us feeling foggy and distracted? And third, can we do anything about this fogginess? Can we train our brain to pay better attention, to have more strong and stable attention in the work that we do in our lives?
So, I wanted to give you a brief glimpse into how we’re going to look at this, a very poignant example of how our attention ends up getting utilized, and I want to do it using the example of somebody that I know quite well. He ends up being part of a very large group of people that we work with, for whom attention is a matter of life and death.
Think of medical professionals, or firefighters, or soldiers, or marines. This is the story of a marine captain, Captain Jeff Davis. And the scene that I’m going to share with you, as you can see, is not about his time in the battlefield. He was actually on a bridge in Florida. But instead of looking at the scenery around him, seeing the beautiful vistas, and noticing the cool ocean breezes, he was driving fast and contemplating driving off that bridge. And he would later tell me that it took all of everything he had not to do so.
You see, he’d just returned from Iraq, and while his body was on that bridge, his mind, his attention, was thousands of miles away. He was gripped with suffering. His mind was worried and preoccupied, and had stressful memories, and really dread for his future, and I’m really glad that he didn’t take his life. Because he as a leader knew that he wasn’t the only one, that was probably suffering, many of his fellow marines probably were too.
And in the year 2008, he partnered with me in the first of its kind project that actually allowed us to test and offer something called mindfulness training to active duty military personnel. But before I tell you about what mindfulness training is or the results of that study, I think it’s important to understand how attention works in the brain.
So what we do in the laboratory is that many of our studies of attention involve brainwave recordings. In these brainwave recordings, people wear funny looking caps that are sort of like swimming caps that have electrodes embedded in them. These electrodes pick up the ongoing brain electrical activity. And they do it with millisecond temporal precision. So we can see these small yet detectable voltage fluctuations over time.
And doing this, we can very precisely plot the timing of the brain’s activity. About 170 milliseconds after we show our research participants a face on the screen, we see a very reliable, detectable brain signature. It happens right at the back of the scalp, above the regions of the brain that are involved in face processing.
Now, this happens so reliably, and so on cue as the brain’s face detector, that we’ve even given this brainwave component a name. We call it the N170 component, and we use this component in many of our studies. It allows us to see the impact that attention may have on our perception.
So I want to give you a sense of the kind of experiments that we actually do in the lab. We would show participants images like this one. You should see a face and a scene overlaid on each other. And what we do is we ask our participants as they’re viewing a series of these types of overlaid images, to do something with their attention.
On some trials, we’ll ask them to pay attention to the face. And to make sure they’re doing that, we ask them to tell us by pressing a button if the face appeared to be male or female. On other trials, we ask them to tell us what the scene was, was it indoor or outdoor. And in this way we can manipulate attention and confirm that participants were actually doing what we said. Our hypotheses about attention were as follows: If attention is indeed doing its job and affecting perception, maybe it works like an amplifier.
And what I mean by this is that when we direct attention to the face, it becomes clearer and more salient, right? It’s easier to see. But when we direct it to the scene, the face becomes barely perceptible as we process the scene information. So what we wanted to do is look at this brainwave component of face detection, the N170, and see if it changed at all, as a function of where our participants were paying attention – to the scene or the face, and here’s what we found.
We found that when they paid attention to the face, the N170 was larger. And when they paid attention to the scene, as you can see in red, it was smaller. And that gap you see between the blue and red lines is pretty powerful. What it tells us is that attention, which is really the only thing that changed, since the images they viewed were identical in both cases, attention changes perception. And it does so very fast, within 170 milliseconds of actually seeing a face.
In our follow-up studies, we wanted to look to see what would happen, how could we perturb or diminish this effect? And our hunch was that if you give people or put people in a very stressful environment, if you distract them with disturbing, negative images, images of suffering and violence, sort of like what you might see on the news, unfortunately, that doing this might actually affect their attention, and that’s indeed what we found. If we present stressful images while they’re doing this experiment, this gap of attention shrinks, its power diminishes.