Problem: It’s not that you weren’t listening when your mom/partner/roommate asked you to pick up more toilet paper on the way home. You just forgot. An honest mistake. You’re only human. Why are you being yelled at?
New research out of the University of Iowa, published in PLOS One, suggests that those moments are particularly human—that people’s memory for things they hear is just not that great. Apparently we already knew this about monkeys.
Methodology: The researchers exposed 82 undergrads to visual, auditory, and tactile stimuli for five seconds each. For the visual information, they showed them silent videos of scenes such as scuba diving; for the audio they went with “easily-recognizable, everyday events” such as dogs barking; and for the tactile stimuli, participants touched common objects such as coffee mugs that were inside opaque boxes, out of sight. The participants also wore headphones while they touched the objects, so that characteristic coffee mug clink wouldn’t give itself away.
After hearing/watching/touching a total of 60 stimuli, subjects moved to the recognition phase, where they experienced 60 more stimuli. Thirty of these were old, repeats from the first round, while they hadn’t encountered the other 30 before. The subjects answered the question “Old or new?” to indicate if they recognized each stimulus. There were three groups for the recognition phase—the first group did the recognition task on the same day as the first task, the second group did it the next day, and the third group did it the next week.
Results: As you’d probably expect, the more time elapsed between the first task and the recognition task, the worse people performed overall. But when the researchers broke it down into the types of stimuli, participants remembered the audio clips significantly less accurately. Subjects’ recognition memory for visual and tactile stimuli did not differ significantly.