“That’s It!”

Now here is the same list of restaurants that we used before to introduce the topic of human memory. This time, we’ll allow the user to interrupt. Read from bottom up to view the passage of time. The leftward-facing “you” is your mind’s eye, holding the target in mind. Your attention must return frequently to that target as you listen to the list, a process called “rehearsal.” Notice that the target is not precise—you’re looking for the “Fox something or other” and you’ll know it when you hear it. The curved arrow represents a comparison between the incoming speech and the target.

Back in the past, you heard, “Benny’s.” You then looked internally at your target and discarded the option. You are now free to forget “Benny’s”—you have no use for it now that it’s discarded. Then the same thing occurs as you listen to the rest of the list. “Li’l Dumplin’” [that’s not it] … “Taco Guano” [that’s not it] … “Star Ship” [that’s not it] … “The Waffle Spot” [that’s not it] … “Homegrown Heaven” [that’s not it] … after each choice you reflect on your target and then discard the option.

Finally you hear, “The Fox and Hound.” That input—residing now in sensory memory—matches your target. The match triggers a “that’s it” response.

As you can see, the user can easily choose if the task is one of recognizing a known target with “that’s it” rather than one of making a more complex decision based on presented options. The distinction is important. If the user is recognizing, then all she must do is compare the item resident in echoic memory with her mental image (already constructed) of her desired goal. If the input resonates with the goal—even if it is not exactly the same word or phrase—then the emerging construct “lights up” inside the user’s mind with a “that’s it” response. “That’s it” is the quintessence of recognition, and takes the form of an image that connects quickly with decisions, actions, changes to the organism, and the follow-on feelings that result from them.

If the input does not resonate with the goal—that is, no recognition occurs in the user’s mind—then it can be forgotten without penalty. The user stops attending to the current list item, and awaits the next input—all the while rehearsing the target to ensure that it remains in short-term working memory.

What this means practically is that lists known to contain a single item that the user can be expected to recognize and act upon can be quite long—perhaps 20 items. The user is not expected to hold any list elements reliably in mind, and the user cannot be expected to attend across more than two or three list elements at the very most. But recognizing is easy, so such lists can be longer.

Note that certain users do not interrupt, and so might fail when selecting from long lists—even if they are only attempting recognition.