When navigating a space, it turns out that human brains form similar spatially conscious brain waves. Scientists have discovered this after devising a method to scan our brains during free movements, instead of standing still on a scanner.
“Our results imply that our brain creates a universal signature to put us in someone else’s skin,” explained neurosurgeon Nanthia Suthana of the University of California, Los Angeles.
Previous studies in rats revealed that low-frequency brain waves help rodents track their position as they explore a new site, defining the boundaries of a site. Similar waves of defining boundaries had also been identified in humans, but only when navigating a virtual environment while standing still for brain scans.
“We wanted to investigate this idea in people (and test if they could control other people nearby as well), but existing technology made it difficult for them,” said UCLA neuroscientist Matthias Stangl.
Thus, Stangl and his colleagues created a mobile brain scanner, consisting of a backpack with a computer that connects wirelessly to the electrodes implanted in the brain (a system called intracranial electroencephalography) to help them study how they form. our brains and remember spatial memories.
The wireless recording device. (Suthana / UCLA Laboratories)
His subjects were five patients with epilepsy who already had electrodes implanted in their brains to help control their seizures. These implants are found in the medial-temporal lobe: our brain fragments are believed to encode long-term intentional memories and spatial cognition.
Participants participated in a 15-minute navigation task where they were asked to find and apprehend the location of hidden targets inside a room. A 15-minute observation task was then performed in which participants had to track someone else navigating the room and press a button when the other person was crossing the unmarked target locations.
The researchers saw that as participants approached a physical limit, such as the wall of a room, the flow of low-frequency oscillations into the brain increased in power. The same thing happened when they saw someone approaching the walls.
“We found that the oscillating changes related to borders were strikingly similar between tasks that required self-navigation versus observing another person,” they wrote in their article.
Recent studies in rats and bats also found that the same group of hippocampal neurons encodes both the animal’s own location and the location of others of its species.
The potency of these brainwave representations of a space, which is visualized below, also increased when participants focused on finding their target location. The oscillation signals were not continuous and did not change the amount they produced, only their strength.
(Suthana / UCLA Laboratories)
On top: Visualized map of the strength of the brain waves from the boundaries of the room in red representing a greater amount of power in the signals of the brain waves.
“Our results support the idea that, under certain mental states, this pattern of brain waves can help us recognize boundaries,” Stangl said. “In that case, it was when people focused on a goal and were looking for something.”
The electrical activity being measured ranged within a frequency range known as theta waves. In general, we produce these slow but pronounced waves as we sail, so it’s not surprising to have them evident in this task.
Interestingly, slightly more vibrant gamma waves also appeared in similar patterns, with a little more variation between different conditions. These are the waves we produce when we use more brains to think, drawing experiences into our working memory.
The team believes the brain waves they observed are generated by multiple groups of neurons that may include cells that encode specifically for boundaries, objects, and other boundaries and target objects. A better understanding of this neural language can help us get rid of brain disorders.
And, in an exciting development, they have made their backpack design available to other researchers. Soon, we can expect to learn even more about our brain wave patterns in complex social situations.
His research was published in Nature.