Research suggests memories are linked to locations

“We’ll always have Paris,” Rick tells former lover Ilsa in the iconic scene in “Casablanca.”

He means that the two will always cherish the memories of their romance, which occurred while both were living in Paris.

But a new study, published in the journal Science, suggests that Rick and Ilsa will literally always have Paris. The research finds that human memories are “geotagged” with information about the place where they occurred.

This means that when someone is trying to a retrieve a memory, such as a conversation with a friend or a youthful time in Paris, the cells which recorded the place where the memory happened — called place cells — activate immediately before the recollection of the memory.

Michael Kahana, a Penn professor who led the study with Andreas Schulze-Bonhage of the University of Freiburg in Germany, said that the study combines the study of episodic memory, which is about “what happened when,” with spatial memory, or “what happened where.” Previously, because of technological constraints, the two types of memory were studied separately and differently.

Video games provided an unlikely solution to this problem, allowing the researchers to “study episodic memory in a spatial context,” Kahana said.

Related: Penn team contributes to Nobel physics research

Participants in the study played a video game where they had to deliver objects to specific locations. At the end of the game, participants were asked to recall what they had delivered. The study was conducted on patients with a form of epilepsy that required them to have electrodes planted in their brains. The electrodes captured the electrical activity happening in patients’ brains, giving scientists a window into the workings of memory.

They found that episodic and spatial memory is “one unified network … the different kinds of memory are all interlinked,” Joshua Jacobs, an assistant professor at Drexel University who worked on the study, said.

“Understanding the processes that lead to episodic memory retrieval is fundamental to the field of neuroscience,” Isabel Muzzio, an assistant professor of psychology at Penn, said in an email.

Related: Faculty undertake the ‘Penn Ghost Project’

The interlinked nature of memory may also help us to understand memory-related diseases. Jacobs points out that the findings help explain why one of the first symptoms of Alzheimer’s is the inability to navigate to previously familiar places. A greater understanding of memory processes could lead to treatments for neurodegenerative diseases such as Alzheimer’s.

According to Muzzio, the study “has provided the building blocks towards this goal.”

Please note All comments are eligible for publication in The Daily Pennsylvanian.