Cognitive Daily

Take a look at the following three animations. Each will flash very rapidly through a set of words (9 words per second!). Your job is to watch carefully and see if you notice a word that describes an occupation that a human performs for money. Such a word may or may not be in each list, and you only get one chance with each one. No cheating!

List 1
List 2
List 3

Did you see an occupation in any of the lists? Just one or two of them?

If you’re like most people, you had no problem spotting “attorney” in the first list, but you missed “carpenter” in the second list. The third list was probably more difficult, but you still likely caught “nurse.”

What’s going on here is a phenomenon called “attentional blink.” We’ve covered attentional blink before, but traditionally the instructions for completing the task are more complicated, calling for people to remember the first time the letter X appears in a flashed list of letters, but only after a white letter (the distractor) appears. Here, the lists consisted entirely of geographical terms, except for the occupation word and (in two cases) a distractor. The distractor words I chose (“passenger” and “husband”) are closely related, but are not occupations, and I didn’t need to mention the distractor at all in order to generate the effect.

A team led by Philip Barnard developed this new way of studying attentional blink in order to shed some light on its causes. The team was able to replicate earlier findings on attentional blink: when the target word followed closely behind a distractor, (200-500 milliseconds) participants were less likely to be able to spot it. When it followed by 600 milliseconds or more, performance improved. So since “carpenter” followed “passenger” by 220 milliseconds in the demo above, you probably missed it. But “nurse” was a full second past “husband,” so you probably saw it (there was no distractor in the first list).

As a control, Barnard et al. also used distractors that were unrelated to job words, like household items. In these cases, the respondents showed no attentional blink.

By using words as stimuli, Barnard et al. were able to do more than just confirm the existence of attentional blink—they could also look at which distractors were more effective. Using a technique called Latent Semantic Analysis, they generated numerical values that represent how closely related any two words are. The value ranges from -1 to 1. So, for example, when nature words are compared to job words, the value is about .14, but when jobs are compared to “human” words like “husband,” the value jumps to .47. Comparing jobs to household items yields an inbetween value of about .30.

Next the team looked more closely at the “human” distractors. When participants correctly indicated that they had seen an occupation word, the human distractor words were most often more closely related to the occupation word. When they incorrectly said that they had not seen an occupation word, the distractors tended to be less closely related to the occupation word.

Barnard’s team argues that this result suggests a two-stage process to attentional blink. During the first stage, people determine if the distractor is unrelated to the other words in the list (in this case, geographical terms). Once the distractor is identified, then the second stage (determining if it is an occupation) begins. During this stage, if the distractor is closely related to an occupation, it’s easier to reject it, because it fits in better with the line of thought we need to use to make the decision (e.g. paid or unpaid). This allows people to return to the initial task and decide if the next word is an occupation word. If the distractor is less closely related, it takes longer to process, and so we are more likely to make a mistake in the primary task.

So it appears that we’re less distracted by either closely related or unrelated items—what gives us the most trouble are distractions somewhere in the middle, because these items distract us during both stages of the recognition process.

Barnard, P.J., Scott, S., Taylor, J., May, J., & Knightley, W. (2004). Paying Attention to Meaning. Psychological Science, 15(3), 179-186.

Comments

#1 Annie
November 15, 2005

It worked for both my husband and I, but both my kids (8 and 11), spotted the word carpenter but didn’t spot either of the other two. What the heck does that mean???
#2 Dave Munger
November 15, 2005

It’s possible that your kids don’t have as good a grasp of the meanings of the words in the list as you do—which means they are less likely to be effective distractors. It’s also possible that the difference is just chance—even when there’s clear evidence of attentional blink, as many as 40 percent of participants identify the target word correctly.
#3 Mortimer Shy
November 16, 2005

This is a futile test that only demonstrates what can be done with uselessly applied technology. Speeding up a list of words? Any tallying the results of it say nothing. Except maybe that a person taking the test ends up depressed whichever way it went. Great fun that is! Cognitive science? People actually employed to devise such poorly disguised amusements are the ones who should be–what’s the word? Unfunded. Blink.
#4 Dave Munger
November 16, 2005

Mortimer,

Let’s assume for the moment that there’s absolutely no practical use for this experiment. Would it still be worth knowing about attentional blink and what causes it? Perhaps not. Perhaps all science should be dedicated towards practical ends. But who gets to determine what’s “practical” and what’s not? Is the study of nuclear energy practical? What about evolution? Initially, it would have been difficult to come up with a “practical” use for Darwin’s theory, but now it is the basis for a wide range of medical technologies.

So perhaps, as you say, this research should not be funded, but how should decisions about research funding be made? This research costs practically nothing—all that is needed is a computer and a few volunteers. Let’s suppose this experiment cost $500. How do we compare that to, say, the International Space Station? At a cost of $116 billion, this project is the equivalent of over 200 million attentional blink experiments. What’s better—funding one space station, or 200 million “poorly disguised amusements?” Isn’t it more likely that one of those “amusements” will turn out to have more practical value than a single space station?

All this, of course, assumes that we already know that attentional blink research has no practical value. I would argue that knowing how and when people become distracted can be critically important when designing such varied items as computer interfaces and traffic signals. But that’s just me. Your opinion may be different. Perhaps you’d rather spend the money designing a better nuclear bomb. The U.S. Department of defense will spend $68 billion on research and development this year. That’s 130 million attentional blink experiments. Maybe if we cut one more psychology experiment and devoted that money to defense spending, the world would be a better place. Personally I’d prefer to give that money to a scientist trying to understand how the mind works, but your opinion may differ.
#5 Len Huber
November 16, 2005

This is my first introduction to the concept of attentional blink. As I school psychologist, I deal with issues of attention among children all the time. Of course, we know that they get distracted, at times, but I’ve always thought the distractions were, by definition, irrelevant to the task at hand. Now I have a new concept, that they can be distracted by unresolved processing issues. Thanks!
#6 Anne
November 17, 2005

I wonder how this works at slower speeds. I am easily distracted & use distractions, digressions & anecdotes a lot in my teaching. Sometimes I think they help keep students focused (as with, say the 3rd animation–a happy little anecdote to reset the attention for the next thing) at others, I think the anecdote itself comes to seem like the point & my substantive point gets lost. Thanks for giving me a new metaphor to use to think about this…
#7 Alex
November 17, 2005

Mortimer

If you get depressed by not being able to spot a word in a list then i suggest you seek help.

I think this experiment is interesting because it shows HOW we get distracted. As an IT student (20) i find this theory useful when thinking about the design of user interfaces etc.

Im no psychology expert but I think its fasinating that our brains can scan words that fast and assess them. When we come across a word that possibly may be the one we are looking for (the distractor) it takes us around 600 milliseconds to assess and decide if this is the word we are looking for, discard it and continue looking. This is shown in this experiment because the words we are looking for are easier to spot when they are longer than 600 milliseconds after the distractor word.

lighten up dude
#8 Alex Barnett blog
November 25, 2005

attentional blink

Dave Munger on a phenomenon apprarently called ‘attentional blink’:

“Take a look at the…
#9 sandscribbler -- Blog Archive -- Attentional Blink
November 26, 2005

[...] Here’s a quick and fascinating exercise that tells us something (I’m not sure exactly what!) about the human mind’s ability to process data. [...]
#10 JM Hanes
December 3, 2005

I spotted all three, BUT I was not as confident about the carpenter. When I got to: “Just one or two of them?” I began to think that maybe I had been mistaken. Interesting. For what it’s worth, I’m an adult with ADD.
#11 Oonagh Duffy
December 13, 2005

what does attentional blink actually tell us about attention?