so what

so what

Thursday, February 25, 2016

Believing is Seeing: Why the car that hit you came out of nowhere and why you turn down the car radio to see better.

“Who are you going to believe, me or your own eyes?” – Groucho Marx

As you know if you read this blog regularly, the vast majority of human mental processing occurs deep beneath our conscious awareness. Our unconscious simply presents us with the results and we are totally unaware of the process - the emotional connections, the unconscious biases, the limits of our senses, and many other variables that shaped the final result. 

There’s a simple reason for this. While the amount of information that can be taken in by our senses is limitless, our brains have very finite resources when it comes to what we pay attention to. This means our senses are pouring a relentless stream of input into our brains every millisecond – far more than can possibly be processed.

To avoid a paralyzing information overload, the brain allows wide streams to flow through almost entirely unprocessed and unassimilated, snatching just a few pieces of selected information for a closer look. It’s particularly sensitive to sudden changes in the environment – anything that moves.  Most likely because things that move, especially fast, could be dangerous.

At one point or another, we’ve all had the experience of feeling that someone was behind us – and, when we turned around, they were!  For the moment, we’ll pretend it was when you were a child and one of your little friends tried to sneak up on you. When you tell the story, you almost inevitably say that you “sensed” someone behind you. The actual explanation is far less spooky.

You saw him.

While your vision has maximum clarity only at the point of focus, called central gaze, it’s a genius at spotting movement. Hold your hands in front of you with your palms out, like you were pushing someone away. Now move them back past your head while wiggling your fingers. You’ll find that you can still see movement almost to a spot directly behind your ears, with far peripheral vision.

There’s very low definition, but movement literally catches your eye because our brains have change-detection mechanisms that automatically direct our attention anywhere there is sudden change. That’s why magicians make broad gestures – they are dragging your central attention away from what they don’t want you to see. It’s called misdirection, and you can’t help following their gestures. Your brain demands it.

Our brain can scan up to thirty to forty bits of information per second - sights, sounds, smells, temperature, and other sensory input, until something grabs its attention. Out of all that flow, our attention filter selects a relatively tiny unit of information to process. Everything else gets dumped like junk mail, without ever entering consciousness.

Cognitive scientists call this “inattention blindness.”  Regular people call it – well, they don’t call it anything because they never realize they are doing it. That’s because the brain is masterful at filling in the gaps, constructing a portrait of reality based on just a momentary glimpse of limited information.

Perception is the ultimate creative act.  And by that I mean that it just makes stuff up.

Not just any stuff, of course. It’s making best-guesses based on what it expects to see, based on a lifetime of similar past experiences.  Perception is largely an automated fill-in-the-blanks response to the world around us.

How do we explain that car that came “out of nowhere”? It’s due to the fact that accidents happen when attention mistakenly filters out really important information and your brain fills in the gaps with what experimental psychologist Kevin O'Regan calls the "Grand Illusion".

For example: you were focused on making a turn into a busy intersection; so the brain filtered out everything except the job at hand, including the car rapidly approaching from an unexpected – and therefore unseen--angle. The brain didn’t expect the car, and therefore didn’t “see” it until it detected movement inside the area it was focused on, an instant before the crash.

What you see is what you expect to see. Did you ever look for your misplaced car keys and not find them until the third search – only to eventually find them in plain sight in a place you looked before?

It happens to everybody. You finally found them in a place you would not normally expect to find them.  The first two times your brain didn't expect to find them there so it skipped right over them. It took two tries before your brain accepted they weren't in any of the expected places and started paying closer attention to the unexpected places. Believing is seeing.

What does it take to capture your attention?

When it comes to catching your visual attention, it depends on how conspicuous the thing is, and there are two ways things become conspicuous.

Sensory Conspicuity involves the physical properties of information. In exhibit design, there is a saying about attracting visitor attention; “Make it big. If you can’t make it big, make it red.” We’d add “and light it up like a cruise ship at sea,” because luminance contrast is more effective in getting things noticed than color contrast.  More important than both of these is contrast with the background - it should stand out. (On the flip side, this is why soldiers wear camouflage to blend in with the background, because being conspicuous in combat is generally considered to be a bad thing).

While they do help, physical properties alone don’t guarantee attention. The real clincher is Cognitive Conspicuity.

Cognitive Conspicuity refers to how you perceive relevance of the information – how important is it to you. Which is why you can hear your name spoken across a crowded, noisy room while holding a conversation with another person. It's called the "Cocktail Party Effect."  We’re a social species. We need to know what people think about us and what their intentions might be – and there’s nothing more personal than your own name. Your unconscious can hear it through the aural clutter and immediately puts you on alert.

Meaningful visual information can also jump out at you automatically. You can glance at a newspaper page and your own name will jump out at you, or the first names of your spouse or children. Your brain didn't read every word, it just looks for meaningful patterns. It's like the common practice of attaching a unique colorful tag to luggage. You don’t peer intently at every piece of nearly identical black luggage – your brain just scans for the flash of color and snaps into attention mode.

By now it should be obvious that with such a limited capability to focus in a world where multitasking is common, the result is that the more ways we divide our attention, the less efficient we are going to be overall.

Every additional task diverts part of your attention, and that leads to mistakes. When we are focused on a complex task, we try to shut out any other input. Have you ever been caught by a flash thunderstorm while driving ? You find yourself trying to see through a curtain of water that overwhelms the capacity of the windshield wipers.

The first thing you do is lean forward to focus all your attention forward, while the second thing most people do is turn down the radio!  It’s an automatic response because your brain is in full-focus mode and doesn’t want any more sensory distraction.  Passengers will stop talking for the same reason.

It’s only in moments like this that we are fully engaged: when we are on a deadline, when we are dealing with an emergency, when the outcome has top social or personal importance. I wish I could also say “when we are driving a 4000-pound vehicle on public streets,” but I can’t.

Reliance on technology has diminished our ability to notice anomalies. Cocooned inside an automobile, we are insulated from conditions on the outside. We mostly drive on the human equivalent of automatic pilot, assuming that the technology will take care of things as usual.

Experiments have demonstrated that when test subjects used a calculator rigged to give absurd math results, their first assumption is that the answer – no matter how ridiculous – is the correct one. The same results were duplicated with cash registers. We expect the machines to be accurate, so we don’t notice when they aren’t until someone calls it to our attention.

We see what we expect to see. We hear what we expect to hear. That’s why we are most likely to make mistakes when new or unusual circumstances are introduced into familiar situations or repetitive tasks. Our experience tells us there is nothing important to notice when carrying out everyday tasks. We do them so unmindfully that we often can’t remember whether we even did them or not. Nothing had ever gone wrong before, so our brains conserves its very limited resources by scanning for something more important.  That’s why we employ technology: to save attention. and when it goes wrong, it can go very wrong.

One early morning many years ago, I was having a cup of coffee in the armory on a military base overseas.  A soldier I knew well was checking out the weapons just turned in by the guards going off-duty. He had the ten weapons lined up on a table in front of him.

He had a routine: take the magazine full of cartridges out of the weapon, pull back the bolt to clear any cartridge still in the breech, look into the breech to make sure it was empty, pull the trigger to close the bolt, put the magazine back in the weapon, and put the weapon on the rack for the next guard shift.

You know where I’m going with this, right?

He got the sequence wrong, returning the loaded magazine before pulling the trigger. He never got it wrong before. It was routine. Even though he was looking at the weapon in his hands while he worked, his brain didn’t think it was worth paying close attention. He had inattention blindness, and he didn’t know it.

And so did I. I had watched him do the same routine so many times before that I was looking straight at him and didn’t see it until after he pulled the trigger.

It’s astonishing how loud a rifle shot in a confined space can be.