A new study offers more evidence that our memories — even for extremely common images — are much poorer that we believe them to be.
The study’s findings suggest that we need to be more humble about our accuracy at remembering things.
For the study, researchers gave 85 undergraduate students at the University of California, Los Angeles (UCLA) a blank sheet of paper and asked them to draw the Apple logo. Each of the students was tested individually (away from others) and given as much time as they needed to complete the drawing. After the test, the students were asked to indicate, on a scale of 1 to 10, how confidently they believed they had reproduced the logo.
The Apple logo was chosen for the experiment because of its ubiquitousness and its relative simplicity. More than 80 percent of the students who took part in the study used at least one Apple product regularly.
After finishing their drawing and declaring their confidence in its accuracy, the students were asked to pick out the Apple logo from eight similar renditions of it. (This test has been put online, if you want to quickly take it now.)
Only one of the 85 students drew the Apple logo perfectly. (Scoring was based on several criteria, including general shape of the apple, the location and size of the “bite,” and the shape and orientation of the leaf.) Another seven students made minimal errors (three or fewer). The rest made many errors.
Regular Apple-product users performed only slightly better on the task than the other students.
Yet, overall, the students had been moderately confident (5.47 on the 10-point scale) about the accuracy of their drawings.
As for the recognition test, only 47 percent of the students correctly selected the real logo, despite expressing confidence that they could do so.
In a second smaller yet similar experiment, students were asked to rate how confident they were about the accuracies of their drawings before as well as after they had finished them. The researchers wanted to see if the drawing test would change how the participants felt about the accuracy of their memories.
It did. The confidence of the students in their ability to replicate the logo plummeted 55 percent after they completed the test. The rest of the findings from this second experiment were similar to those of the larger one.
What causes our poor memory for common objects and images? It has to do, at least in part, with a phenomenon called “attentional saturation,” explains two of the study’s authors, UCLA psychologist Alan Castle and graduate student Adam Blake, in a commentary for Psychology Today:
Through constantly seeing and attending to the same thing over and over again, our brains may learn that it is unimportant to remember the specific details — if we ever need to find them we can just look around! This same principle can be applied to pennies and even fire extinguishers and keyboards. When we first encounter one of these things, we might have a very distinct representation of it in our memories. But with continued use, that distinct memory may blend with other experiences with the object to the point that we start to only really pay attention to the important characteristics: it helps me pay with exact change, my fingers need to do this to make this word, I need it to put out a fire, or it represents a popular brand (and not a counterfeit, perhaps!).
Strangely, we are largely unaware of this phenomenon as we go about our day. In the study involving the Apple logo, participants were asked prior to drawing the logo how well they would be able to draw it. There was a striking discrepancy between participants’ confidence prior to drawing the logo and how well they performed on the task. After the drawing task, there was a large drop in confidence, a finding that suggests that the act of trying to retrieve the logo from memory was a good method of “updating” ideas of how available that memory was.
This type of retrospective judgment of memory is widely known in the literature to be superior to prospective judgments, and it applies to other types of memory as well. So, if you want to really know how well you know something, the best thing you can do is to actually try to use that information in a meaningful way — it will often be a very telling experience.
The study was published in the Quarterly Journal of Experimental Psychology, where it can be downloaded and read in full. You can read Castel and Blake’s discussion of the findings on Psychology Today’s website.