Physical movement and memory are so closely intertwined that even a seemingly meaningless motion, like moving marbles from one box to another, alters the speed and tenor of recall.
The marble-moving study was performed by Daniel Casasanto and Katinka Dijkstra, psychologists at the Max Planck Institute and Erasmus University, and published in March in the journal Cognition.
In earlier studies, the group showed how right-handed people associate positive emotions with the rightward direction, and negative with left. Left-handed people experience the opposite. They’ve also shown that people are better at recalling activities when their bodies are engaged in relevant postures. Other researchers have documented how smiling and frowning alters emotion, and how sitting upright or slumping affects cognitive performance.
Researchers have proposed two explanations for these results. Casasanto and Dijkstra think that motion is metaphorical. We’ve come to associate spatial characteristics with emotional values in our minds, and physical motions activate the same pathways: Jumping sends spirits soaring. Other researchers suspect the link is more direct. They think that we associate memories with physical movements involved in their formation. A nasty fall once caused pain, so falling has negative connotations forever.
To investigate the mechanisms tying motion to memory, Casasanto and Dijkstra instructed 24 college students to move marbles with both hands between two stacked boxes. As they moved the marbles, they were asked about times they had “felt really cool,” “ate something delicious” and other emotion-specific experiences.
When moving the marbles upward, the students were quicker to recall positive experiences and slower to remember the negative. When moving marbles down, happy memories came slowly and sad memories fast.
In the second part of the study, students were asked more general questions, such as “tell me about something that happened last summer.” When moving marbles up, they were more likely to recall a happy time. Moving marbles down brought back unhappy memories.
Because moving marbles is a motion not likely linked to a specific memory, the findings suggest a metaphorical link between motion and memory, say the researchers. Of course, there could still be a direct link in other circumstances. But whatever the explanations, the results add further weight to the idea that bodies are not simply vehicles for our brains, but an important part of our minds.