Verified by 
Key points
- Memory castles improve memory retrieval by activating location memory in the brain.
- Jennifer Aniston neurons are a type of location-sensitive brain cell.
- Memory castles activate spatial navigation brain regions, suggesting a link between location memory and recall.
Several months back, my wife and I were at Warner Brothers Studios. We came across the set from the sitcom Friends and I saw a photo of Jennifer Aniston. Immediately, I had a flashback to a small office space in Milwaukee where I used to work as a backstage physician for a large music festival. What’s the connection? One night, several years ago, while working for a certain performer, I was standing by myself in an office and Jennifer Aniston walked in. I introduced myself and we had a nice conversation (or at least I thought we did).
While I was a little surprised that seeing a photo of Aniston brought me back several years to a specific office in Milwaukee, scientists can now explain how this occurs through two distinct, yet related phenomenon.
First, in 2005 a team of researchers led by Rodrigo Quian Quiroga at the University of Leicester found something very unusual.1 Using electrodes implanted in the brains of epilepsy patients as they looked at pictures of different people, places, and objects, they found a specific neuron that fired consistently at the sight or mention of a famous actress, or information associated with her, such as her voice or a scene from one of her movies. That actress? You guessed it: Jennifer Aniston.
This “Jennifer Aniston” neuron is part of a larger network of neurons in the medial temporal lobe, known to play a crucial role in the formation of new memories. The neuron fires not only in response to pictures of Jennifer Aniston, but also to pictures of other celebrities and even famous landmarks. What makes it unique is its consistency: It fires every time a subject is presented with a picture of Aniston, but not with other stimuli.
This discovery has significant implications for our understanding of how the brain processes and stores information and sparked the idea that memories may be stored in a distributed manner throughout the brain, with specific neurons serving as "memory tags" for particular stimuli.
The second line of related research involves spaces and locations. Several studies have shown that location memory can be linked to specific neuronal firing patterns in the hippocampus, another area of the brain associated with memory formation. Participants monitored using functional magnetic resonance imaging (fMRI) navigated through a virtual city. When they reached specific locations in the city, certain hippocampal neurons fired more strongly, showing that the brain uses these firing patterns to encode and retrieve memories of specific locations.
Putting these two types of research together suggests that the brain may use a system like the Jennifer Aniston neurons to link memories to specific locations. In other words, location memory can be linked to specific neuronal firing patterns. These findings have led to new insights into how we can improve our memory and recall abilities. They also explain why the “memory castle” or “memory palace” technique for memorizing is so effective.
The "memory castle" method involves creating vivid mental images of information you want to remember and placing those images in specific locations within a familiar setting, such as a house or a castle. By doing so, the brain can create strong neural connections between the information and the location, aiding in memory recall. Mentally "walking" through the environment and recalling the information associated with each location, one can improve their memory and recall abilities for that information. (Joshua Foer's book, Moonwalking with Einstein,3 goes into detail about how people with normal memories can train their brains to become super-memorizers, using this technique to capitalize on the brain's natural tendency to encode and retrieve memories based on spatial location.)
What's more, neuroimaging studies have shown that using a memory palace can activate the same regions of the brain that are involved in spatial navigation, suggesting a link between location memory and memory recall. This supports the idea that the brain may use similar neural mechanisms to store memories and navigate physical space.4
By using a memory palace, you may be able to recall about 35 words from a list of 40 instead of around 10 using rote memorization techniques.5 The memory palace technique can also be effective for people with age-related memory decline or neurological conditions such as Alzheimer's disease, suggesting that it may have important practical applications for improving cognitive function in older adults.6
One key aspect of the memory castle technique is retrieving episodic memories (or autobiographical memory retrieval)—the type of memories associated with specific locations or mental “rooms." The underlying neural mechanisms involve the reactivation of neural patterns between the hippocampus and prefrontal cortex that were formed during the encoding of the memory, similar to the concept of the Jennifer Aniston neuron.7,8 This process, and memory retrieval, can be enhanced by the use of transcranial direct current stimulation to the prefrontal cortex.9
The memory castle technique relies on the creation of a mental map or spatial layout of information to aid in memory recall. The hippocampus and prefrontal cortex are intimately involved in the creation and utilization of these mental maps, providing support for the use of spatially-based memory techniques.10
How do we put together these two concepts of location memory with a specific Jennifer Aniston neuron? Mental representations of concepts and their closely related concepts, like meeting Jennifer Aniston in an office years ago and the associated performer with whom I was working, the weather that night, and other information, may be organized and represented in a “conceptual map." We can use this knowledge to aid our memory recall and retrieval. I have personally used the memory castle technique successfully for many years to memorize shopping lists, to-do lists, and even to learn material during university and medical school.
So, the next time you're struggling to remember something important, try using a memory palace and see if you can tap into your very own Jennifer Aniston neuron. You may just surprise yourself with what you're able to remember.
