Hearing memories fade, but the visual ones linger

By Christine Jasoni 13/04/2014

I don’t know how many times I need to ask my husband to get milk on the way home. And do you think he remembers? Turns out, he’s not alone. And what’s more – he’s normal. New neuroscience research [1] has revealed that we are way better at remembering things that we see or touch, than we are at things we hear.

Before this research, scientists believed that all memories were entered and stored in our brains in the same way, no matter whether we remembered faces, telephone numbers, or a story. This new study suggests that this is not entirely true, and here’s how the scientists proved it.

Study participants were asked to listen to short tones through headphones, look at various shades of red squares, or feel low-intensity vibrations by holding on to an aluminium bar. Participants were then asked to recall what they heard, saw, or felt after a time delay of up to 30 seconds. With a short delay between the sensory experience and the recall, most participants remembered well. But as the delay got longer, people began to forget. This isn’t surprising, we know how our memories can fade as time goes by.

What was curious though, is that the memories did not all fade at exactly the same rate. Memories of things that people saw (red squares) or felt (vibrating bar) lasted significantly longer than the things that people heard (tones). In fact, people were able to remember the tones only for about 4 seconds. I was surprised by this because it seems so short. But it’s a bit like when someone gives you their telephone number – if you don’t dial it or write it down straight away, it’s as good as gone.

One odd thing that struck me about this experiment is that people were being asked to remember weird things that were irrelevant to their lives, so maybe it is not surprising that they forgot them quickly. What about memory for things that they might encounter in everyday life? In a second set of experiments, participants listened to recordings of dogs barking, watched a sport video with the sound off, or held objects, such as a coffee cup, that were hidden from view. Turns out the results were pretty much the same – people could remember the things they saw or felt for up to one week more than the things that they heard.

This new research is hugely important for teaching and learning, since it suggests that pupils will remember better if material is presented visually and/or “hands-on” rather than just from hearing a lecture. But whether I provide a song and dance about milk to get my husband to remember is another story entirely.