We all have a friend who can arrive in a foreign city where the streets are laid out like tangled lanyard and manage to find all the basilicas, catacombs and shuttered bolshevik headquarters without once asking a shopkeeper or pestering a passerby. Somehow, these natural-born navigators don't need to set their eyes on the parliament or take a whiff of the marina to get around like locals.
But, while some people do seem like human homing pigeons, we all have neural navigation systems. And, according to a new study from UC Davis, published in the journal Neuron, our internal GPS still works when we don't have any real, physical cues to help us understand which f-ing victorian garden we're standing in this time. What's more, the study suggests that if teleportation ever becomes the new air travel, we won't get lost when we step into the spatial abyss.
The research helps clarify longstanding debate about the purpose of low-frequency oscillations that flare up in the brain's hippocampus when we're on the go, whether we're walking through an urban jungle or cruising down the 101.
The hippocampus, which sits in the brain's medial temporal lobe, is heavily involved in spatial processing and memory. It's home to an interlocking network of cells and electrical ciruits that's been dubbed the "brain's GPS system," a discovery that earned Norwegian scientists a Nobel Prize in 2015. Researchers have known for some time that the low-frequency oscillations play a role in navigation because activity consistently picks up during directional tasks. But their exact function hasn't been as clear. The UC Davis team believes their work helps lift the fog.
Prior to this study, scientists developed a few theories to explain the hippocampal oscillations. One says the mysterious activity is primarily a response to our brains perceiving and making sense of some material space that we're navigating. But, another theory says the oscillations are related to memory processing, meaning they're present even we aren't actively orienting ourselves in the world.
To figure out more about the purpose of the oscillations, the UC Davis team set up a virtual reality experiment. They recorded hippocampal EEG activity in human patients who had to navigate a virtual world. The virtual world bore the features of the real, corporeal world we inhabit — streets, shops and so on. But, it also contained teleporters, which are essentially sensory black holes without visual (or other) cues to use for navigational purposes.
If the oscillations depended on patients having some sensory information to process, researchers posited, then the oscillations would weaken or disappear entirely when patients went into the teleporters. But, if the oscillations persisted during virtual teleportation, then we'd have evidence the brain's GPS system can run on memory alone, and doesn't need external cues to function.
As it turned out, the oscillations stayed strong inside the teleporters. "We show for the first time that even when these visual cues are removed, low-frequency hippocampal oscillations persist when humans experience virtual movement through space," wrote study authors in their paper.
In other words? We can find our way through the world without actually being in it. "Once teleportation occurs in the natural world," said study co-author Arne Ekstrom, "our brain can use existing neural mechanisms for navigation."
So, we don't need to trip over real cobblestones to know we've finally hit the historic district.