100 Things You Should Know About People: #60 — Cognitive "Loads" Are The Most "Expensive"

Confused person at computer
Cognitive loads are expensive

You are paying bills at your online banking website. You have to think about what bills need to be paid when, look up your balance, decide how much to pay on your credit cards, and push the right buttons to get the payments processed. As you do this task, you are thinking and remembering (cognitive),  looking at the screen (visual), and pressing buttons, typing, and moving the mouse (motor).

In human factors terminology these are called “loads”. The theory is that there are basically three different kinds of demands or loads that you can make on a person: Cognitive (thinking and remembering), Visual, and Motor.

Not all the loads are equal — Each of the loads uses up different amounts of mental resources. You use up more resources when you ask people to look at something or find something on a screen (visual) than when you ask them to press a button or move a mouse (motor). You use up more resources by asking people to think or remember or do a mental calculation (Cognitive), than when you ask them to look at something on a screen (Visual). So from a human factors point of view, the order of the loads from most “expensive” to least is:

  • Cognitive (most “expensive”)
  • Visual
  • Motor (least “expensive”)

It’s all about trade-offs — From a human factors point of view, when you are designing a product, application, or website,  you are always making trade-offs. If you have to add a few clicks, but by doing so the person doesn’t have to think or remember as much, that is worth it. Clicking is less of a load than thinking. I once did some research on this topic. People had to go through more than 10 clicks to get the task done, and at the end they would look up and smile and say, “That was easy!” because each step was logical and gave them what they expected. They didn’t have to think. Clicking is less of a load than thinking.

Continue reading “100 Things You Should Know About People: #60 — Cognitive "Loads" Are The Most "Expensive"”

100 Things You Should Know About People: #58 — People See What They Expect To See

Picture from airport xray machine
Why do airport screeners miss guns in carry-ons?

During December of 2009, Farid Seif, a businessman from Houston, Texas, boarded a flight in Houston with a loaded handgun in his laptop case. He made it through security without a problem. Farid is not a terrorist. The gun is legal in Texas; he forgot to take it out of his laptop case before his travel. Farid realized the mistake when he got to his destination at the end of the trip.

Airport security at the Houston airport did not detect the gun. It would have been easily seen by a security screener through the scanner at the airport, but no one noticed it.

Homeland Security in the US routinely tests the ability to pass security screening with guns, bomb parts, and other forbidden materials, by sending people through undercover with material. The US government hasn’t released the figures officially, but the estimate is that 70% of these tests fail, meaning most of the time the undercover people are able to get through security, like Farid Seif, with objects that are supposed to be spotted.

People get used to the frequency of an event Why do the security personnel notice the bottle of shampoo that is too large, but miss a loaded handgun? Research on attention gives a hint on why this might happen. It has to do with the expectation of how frequently an event does or does not happen.

Continue reading “100 Things You Should Know About People: #58 — People See What They Expect To See”

100 Things You Should Know About People: #39 — Your Mind Wanders 30% of the Time

Photo by Dave Grave*

You are at work reading a report that one of your colleagues has written and you realize that you’ve just read the same sentence about three times. Instead of thinking about what you were reading, your mind wandered.

Mind wandering is similar to, but not the same thing as daydreaming. Psychologists use daydreaming to refer to any stray thoughts, fantasies, or stories you imagine, for example, winning the lottery, or being a famous celebrity. The term mind wandering is more specific, and refers to when you are doing one task and then fade into thinking about something that is not related to that task.

Mind wandering is a very common phenomena – We underestimate our mind wandering; according to Jonathan Schooler of UC, Santa Barbara, we think our minds are wandering about 10% of the time, when it is actually much more. In normal every day activities our mind is wandering up to 30% of the time, and in some cases, for instance when driving on an uncrowded highway, it might be as high as 70%.

Wandering minds annoy some neuroscientists – Some neuroscientists became interested in studying wandering minds because they were such an annoyance while doing brain scan research. The researchers would have subjects do a certain task, for example, look at a picture, or read a passage, while scanning for brain activity. About 30% of the time they would get extraneous results which did not seem to be related to the task at hand. That’s because the subject’s mind was wandering from the task at hand. Eventually the researchers decided to start studying the wandering rather than just getting annoyed by it.

Why a wandering mind can be a good thing – Mind wandering allows one part of the brain to focus on the task at hand, and another part of the brain to keep a higher goal in mind. So you are driving and paying attention to the road, but you are also thinking about when you should stop for gas. Or you are reading an article online about a thyroid medication called Synthroid that your doctor thinks you should take, but your mind wanders to the idea that you should put that salon appointment on your calendar. Mind wandering might be the closest thing we have to multi-tasking. It’s not really multi-tasking, (which doesn’t exist…you can see my previous blog post on that), but mind wandering does allow you to keep important goals in mind while doing one thing.

Why a wandering mind can be a bad thing – Much of the time when our mind wanders we aren’t aware of it. More “zoning out” than “mind wandering”, this means that we can miss important information. For example, if you are supposed to be reading that report from your colleague, but you are instead thinking about what to make for dinner, that may just mean you are being unproductive. We aren’t usually aware when we are zoning out.

More mind wandering = more creativity – The researchers at UC, Santa Barbara have evidence that people whose mind wanders a lot are more creative and better problem solvers. Their brains have them working on the task at hand, but simultaneously processing other information, and making connections.

Mind wandering and the internet – I’ve been thinking about the fact that the ability to quickly switch from topic to topic is what the web does really well.  Is web surfing related to mind wandering? Here are some of my mind wanderings on this topic:

  • Do we like web surfing because it enables this type of wandering?
  • Rather than designing web sites to try and hold people’s attention should we design to encourage wandering?
  • Should we build in feedback about the wandering so that it is easier to get people back to the original thought?

What do you think?

If you like to read research:

Christoff, et. al., Experience sampling during fMRI reveals default network and executive system contributions to mind wandering. Proceedings of the National Academy of the Sciences, May 11, 2009.

Mason, et. al., Wandering Minds: The default network and stimulus-independent thought. Science, January 19, 2007.

Photo Credit: : http://www.flickr.com/photos/daveograve/

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100 Things You Should Know About People: #34 — Too Much Stress Results In Poor Performance

Yerkes Dodson LawA few days ago I found myself in a hotel room outside of Chicago with my 19 year old daughter moaning and sometimes howling in pain. She’d been sick for a week, each day with a new symptom, and this morning her eardrum felt like it was going to burst. We decided that I should cancel my client meeting and take her to an urgent care clinic instead. Of course, we don’t have universal health care here in the States, so first I had to call my insurance provider to find out if there were “in network” doctors we could go to and still be covered by our plan. The insurance company told me to go to a particlar web site,  and said that any doctor we picked through that site would be considered in network.

Using a web site under stress — By now 10 minutes have passed and my daughter is still sitting on the bed behind me moaning and wailing. Instead of helping her, I have to go to a web page and fill out forms and look at maps. The first thing that happens is that I encounter a drop down menu that is meaningless to me:

Beechstreet.com website

When I look at this web page now (days later, crisis has passed), it doesn’t seem too confusing, but when I was trying to fill it out, trying to get my daughter some help, the web page was daunting and impossible, and not at all intuitive.

Stress changes your perceptions — Research on stress shows that a little bit of stress (called arousal in psychology terms) can help you perform a task, because it heightens awareness. Too much stress, however, degrades performance. Two psychologists, Robert Yerkes and John Dodson first postulated this arousal/performance relationship, and hence it has been called the “Yerkes-Dodson law” for over a century.

Arousal helps up to a point — The law states that performance increases with physiological or mental arousal, but only up to a point. When levels of arousal become too high, performance decreases. Research on the law shows that the amount of stress/arousal that is optimal depends on how difficult the task is. Difficult tasks require less arousal to reach optimal performance, and will start to break down if the arousal level is too high. Simpler tasks require more arousal and don’t fall off as fast.

Yerkes-Dodson Law
Yerkes-Dodson Law

Tunnel vision — When arousal first goes up then there is an energizing effect, as the person is paying attention. But as the stress increases there are negative effects. Attention gets unfocused, people have trouble remembering, problem solving degrades and “tunnel vision” sets in. Tunnel vision is where you keep doing the same task over and over even though it isn’t working.

Glucocorticoids — More recent research has shown a similar curve when studying the presence of glucocorticoids. These are the hormones that are released when we experience stress, so the Yerkes-Dodson law appears to have direct physical evidence.

Maximum frustration — As I tried to use the web page to find a doctor I kept getting errors, and typical of someone under stress, I kept doing the same task over and over even though it wasn’t working (tunnel vision). At one point I was crying tears of frustration, cursing over the lack of usability of the web site, and upset that I could not just find the name and address of a clinic we could go to.

Patient care, not computer care — I finally turned away from the computer, got my daughter some tylenol, gave her warm washclothes to hold against her ear, and got us both calmed down. Then I found a clinic at the website  (where we went later that day, only to have them say she was fine. By the way, our insurance didn’t work and we had to pay cash after all — i.e., I didn’t need the web site). My daughter is better, and I didn’t even have to cancel the client meeting.

Test under stress — If you might have people using your site when they are under stress, keep in mind that too much stress will change the way they see and use the web site. And here’s a plea to BeechStreet.com… test your website thoroughly assuming that people are tense, stressed, and with howling children in the background. It’s a totally different experience.

If you’d like to read the research —

Yerkes RM, Dodson JD (1908). “The relation of strength of stimulus to rapidity of habit-formation”. Journal of Comparative Neurology and Psychology 18: 459–482. http://psychclassics.yorku.ca/Yerkes/Law/.

Lupien, SJ, Maheu F, Tu M, Fiocco A, Schramek TE (2007). “The effects of stress and stress hormones on human cognition: Implications for the field of brain and cognition”. Brain and Cognition 65: 209–237. PMID 17466428.

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100 Things You Should Know About People: #20 — Your Attention Is Riveted By Pictures Of People

Picture of a baby looking right at the camera Second only to movement (animation, video), pictures of a human face capture attention in any medium, including websites. Pictures of a human face not only capture attention, but keep the attention on that part of the screen even when the picture goes away.

We start young — With some creative experiments it has been proven that babies as young as 4 months old will look at pictures of other people more than pictures of other objects or of animals. And this preference for faces continues throughout the life span. It seems to be part of our brain wiring.

The eyes have it — Research using eye tracking shows that when you show people a picture of the face of a person, their attention goes mostly to the eyes. If you want to capture someone’s attention at a website, showing a picture of a person who is looking right into the camera captures the most attention. Continue reading “100 Things You Should Know About People: #20 — Your Attention Is Riveted By Pictures Of People”

100 Things You Should Know About People: #18 — What People Look At On a Picture Or Screen Depends On What You Say To Them

Yarbus Eye Tracking Picture
Yarbus Eye Tracking Picture

Eye tracking is a technology that allows you to see and record what a person is looking at, and for how long. One way it is used is to study web sites to see where people are looking on a web page, where they look first, second, etc. It’s a pretty interesting technology, one of the benefits being that you don’t have to rely on what people SAY they are looking at, but can collect the data directly. Like any technology, however, it’s not perfect, and one of the problems with eye tracking is that you can’t just give people a web site to look at and then assume that where they look is what they are “really interested” in.

We underestimate the effect our instructions have on where someone looks. Look at the picture at the beginning of this post. In research by Yarbus, people were shown this picture, and then given different instructions of what to think about while looking at the picture. Below are the eye gaze patterns matched with the instructions that people were given: Continue reading “100 Things You Should Know About People: #18 — What People Look At On a Picture Or Screen Depends On What You Say To Them”

100 Things You Should Know About People: #11 — Why You Can't Resist Paying Attention to Food, Sex, or Danger

burgersmall
Food Captures Attention

Have you ever wondered why traffic always slows when people are driving by an accident? Do you moan about the fact that people are attracted by the gruesome, and yet find that you glance over too as you drive by? Well, it’s not really your fault, you (and everybody else) can’t resist looking at scenes of danger. It’s your “old brain” telling you to PAY ATTENTION.

You have 3 brains — In my book, Neuro Web Design: What makes them click? I talk about the idea that you really don’t have one brain, you have three. The “new brain” is the conscious, reasoning, logical brain that you think you know best; the mid brain” is the part of the brain that processes emotions, and the “old brain” is the part of the brain that is most interested in your survival.

From reptiles to people — If you look at brains from an evolutionary perspective, the “old brain” developed first (hence the name “old brain”!). In fact, that part of our brain is very similar to the brain of a reptile, which is why some people call it the “reptilian” brain. Continue reading “100 Things You Should Know About People: #11 — Why You Can't Resist Paying Attention to Food, Sex, or Danger”

100 Things You Should Know about People: #1– You Have "Inattention Blindness"

I’ve decided to start a series called 100 Things You Should Know about People. As in: 100 things you should know if you are going to design an effective and persuasive website, web application or software application. Or maybe just 100 things that everyone should know about humans!

The order that I’ll present these 100 things is going to be pretty random. So the fact that this first one is first doesn’t mean that’s it’s the most important.. just that it came to mind first.

I hope you enjoy this series. Make sure to let me know by posting comments.

So here’s #1 — Inattention Blindness

First let’s start with a little test for you to take. Watch the video below:

This is an example of what is called “inattention blindness” or “change blindness”. The idea is that people often miss large changes in their visual field. This has been shown in many experiments. Here is a description of an experiment conducted outside the lab:

So what does this mean if you are designing a website or something on a computer screen? It means that you can’t assume that just because something is on the screen means that people see it. This is especially true when you refresh a screen and make one change on it. People may not realize they are even looking at a different screen. Remember, just because something happens in the visual field doesn’t mean that people are consciously aware of it.

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