This is Your Brain at Work

John Medina was recently interviewed by the New York Post. The complete article, "This is Your Brain at Work," is available here.

How is work an antibrain environment?

We don't very much know how the brain works, but we do know something about its performance envelope. The brain appears to have been designed to solve problems related to surviving in an outdoor setting in unstable meteorological conditions. And to do that in near-constant motion. That's what the brain's good at. So if you wanted to design a work environment directly opposed to what the brain was naturally good at doing, you'd design something like an office.

If you tore the workplace down, what would you replace it with?

We've known for some time that the more fit aerobically you are, the better a particular series of processes called "executive function" in the brain works. It helps your ability to do math. It helps your ability to control your impulses. It helps with Let's say you're a Boeing engineer. Executive function is the very thing that allows you to design a satellite and, at the same time, keeps you from punching your boss in the nose when you get a bad performance review.

If you take somebody who's fat and sedentary and exercise them three times a week for as little as three months, you can get anywhere between an 80 and 120 percent increase in executive function. In our evolutionary history, we were probably walking anywhere between 10 and 20 kilometers per day. If we sat around in the Serengeti for half an hour, we were usually lunch.

Scotch the cubicle, put in a treadmill and do all your computer work while you're walking two miles an hour.

How does sleep, or lack of it, affect the brain at work?

There's a time in the afternoon when your brain wants to do a reset. And during that time it wants to take a 15- to 20-minute nap. We call it the nap zone. If you don't allow yourself to take a nap during that time, you'll fight being sleepy the rest of the afternoon, and productivity can suffer.

It was measured by NASA. They were able to show that by giving their fighter pilots a 20-minute nap in the nap zone, you'd find an increase of about 34 percent in their mean reaction time performances.

Mark Rosekind, the guy who did the study, goes, "Look, what other management technique can I do that, in 20 minutes, gives a 34 percent boost in productivity?"

Related Links:

Interview in the New York Post

Sleep Slide Show

Why do we sleep?

Exercise boosts brain power

Discuss on the Facebook fan page

Brain Rules for public speaking

Scott Berkun recently interviewed John Medina for his blog Speaker Confessions. Scott asks the question: what makes public speakers good or bad? He's working on a book to answer that question.

SB: How can a lecturer use attention, but make sure not to abuse it? Or put another way, does repetitive use of phasic alertness, getting an audience to refocus their attention ever few minutes, have declining effects over time?

JM: I do not believe in entertainment in teaching, during the holy time information is being transferred from one person to another. I do believe in engagement, however, and there is one crucial distinction that separates the two: the content of the emotionally competent stimulus (“hook”). If the story/anecdote/case-history is directly relevant to the topic at hand (either illustrating a previously explained point or introducing a new one), the student remains engaged. Cracking a joke for the sake of a break, or telling an irrelevant anecdote at a strategic time is a form of patronizing, and students everywhere can detect it, usually with resentment, inattention or both.

Do you think the size of a classroom has any effect on students ability to pay attention? Does Posner’s model of attention change if we are alone in conversation, vs. in an audience of 99 other people listening to a lecture?

I don’t think the size of the classroom has anything to do with the functional neural architecture proposed by Posner, but there is a universe of difference in how it behaves. The behavior has to do with our confounded predilection for socializing. People behave very differently in large crowds than they do in small crowds or even one on one. Very different teaching strategies must be deployed for each.

Bligh’s book “What’s the use of Lectures?” identifies 18-25 minutes, based on his assesment of psychology studies, as the key breakpoint for human attention in classrooms. Whether it’s 10 or 25, why do you think so few schools or training events use these sized units as the structure for their days, or their lessons?

I don’t know why schools don’t pay attention to attention. Perhaps it is a lack of content knowledge. If I had my way, every teacher on the planet would take two courses: First, an acting course, the only star in the academic firmament capable of teaching people how to manipulate their bodies and voices i to project information. Second, a cognitive neuroscience course, one that teaches people how the brain learns, so teachers can understand that such projections follow specific rules of engagement.

The Physics of fMRI

I almost destroyed the backseat pocket of an airline seat this summer. The vandalism was inadvertent, assuredly, though the anger that fueled it was not. While waiting for my plane to take off, I had read a magazine article claiming to show that fMRI (functional magnetic resonance imaging) studies were “uncovering” the voting preferences of test subjects. An adjacent article announced that researchers could now predict the buying preferences of other test subjects using the same imaging technologies.

I was puzzled. How could Fourier transforms performed on signals coming from someone’s cortex say anything about their politics? What could possibly have reduced the interpretation of these noninvasive imaging data to conceptual phrenology? I got so mad as I thought more about it that I jammed the articles back into the pocket, aggravating an already ripped inner seam.

The column you are reading is an attempt to push this admittedly hot reaction into a more positive direction. . . and for a good reason. There are growing numbers of articles in the popular press describing “breakthroughs” in our understanding of human cognition—and how noninvasive imaging data are changing the way we view the brain. Nothing wrong with that, certainly. There has been an explosion of studies using functional (f)MRI technologies and their like. But are the data being revealed strong enough to predict subjective behaviors, such as voting habits? As you can probably guess from my tone, the answer of this bioengineer is “no,” or at least “not yet.”

I have decided to do something positive about these “headlines.” For now, and in my next 2 columns, I will describe how fMRIs actually work and what is the least luxurious, most conservative way to interpret the view they give us about cognition. Given the conceptual and technical complexity, it is easy to misconstrue what imaging technologies can divulge about human cognition.

Starting with quarks (literally) and ending with scans of emotional behavior, we will explore some of the biophysical underpinnings of this promising (and may I say limited) technology. The hope is that by knowing a bit about the technical aspects of fMRI, we will better understand what it can—and cannot—measure. This will allow us to treat with greater skepticism, and more sobered excitement, the view that fMRIs are giving us about how our brains work.

This first installment deals with some basic physics. I review a few properties about magnets and radio waves that you might not have thought about since your undergraduate days. In part 2, I will focus on the types of molecular interactions these magnets and radio waves actually measure when trained on an actively thinking brain. The third column will relate how this knowledge reveals both the strengths and limitations of using imaging technologies to discover aspects of human cognition.

THE 40,000-FOOT VIEW
We begin with the name. As you know, fMRI is short for functional magnetic resonance imaging. The core idea of fMRI has been around for a long time. Originally called just NMR (nuclear magnetic resonance), this technology found great utility in the organic and inorganic laboratories. When it came time to apply the technology to biological tissues (from ideas originally developed by Paul Lauterbur), the word “nuclear” was thought to have too many negative connotations. It was dropped in favor of the more socially compatible “functional.”

To understand how an fMRI scanner generates images, we have to break the machine down into its component parts. All fMRIs possess 3 general “gadgets.” The first is a device that can generate a powerful magnetic field. The second is a coil that can create powerful radio frequency pulses. The third is a highspeed computer, preloaded with a lot of very sophisticated signal processing software, all programmed to produce an image capable of making sense to a researcher. How these 3 gadgets work together is fairly easy to understand, at least at the 40,000-foot level. The magnet in the fMRI transforms tissues into a visualizable state; the radio frequency pulses provide the signaling information necessary to discern them. The computer assembles the information from the radio frequency pulses into a form instantly recognizable to anyone who can read a weather map. Indeed, part of the problem with misinterpreting fMRIs is that the information seems so accessible.

To make sense of how these gadgets work together, we have to understand how magnets and radio frequencies act at the subatomic level. These interactions are essentially the same physical
processes you see on display every time you turn on your radio.

Download the PDF to read the rest

This column appeared in the April issue of Psychiatric Times. More columns available here.