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!
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.