One day you can see yourself breathing fresh air on an idyllic solitary island, with the clean ocean at your feet and your arms bathed in warm light while the sun sets on waters that undulate slightly ... Nothing around you except the perfect nature and you. You will ask yourself, is this real? Or are scientists projecting holograms in my brain to create a vivid sensory experience that is not really happening? For precisely a group of researchers from the University of California at Berkeley (USA) is in the early stages of assessing their ability to create, edit and eliminate sensory experiences of our brains, both in real time and in our stored memories. .
Would you put your brain in the hands of scientists who can create immersive worlds and even fool your mind to think that these images are real? This team of neuroscientists is trying to reverse engineer experiences by stimulating neurons to excite the same neural patterns.
Currently, the steps to achieve this are ... a bit invasive. Scientists genetically modify neurons with photosensitive proteins so that they can carefully manipulate neurons using light. This is what we know as optogenetics, for which a metal plate must also be implanted surgically on the target area.
In the new study, published in the journal Nature Communications, the scientists announced an essential first step to simulate false sensations in the human brain that are so real that our brains can think that they really are ours, that we experience them at some time.
Researchers Nicolas C. Pégard, Alan R. Mardinly and Ian Antón Oldenburg (under the supervision of Hillel Adesnik), detailed how they 'hacked' the brains of laboratory rats to create such false images. They used laser lighter flashes in the brain to activate or suppress individual neurons. By doing this, they were able to simulate patterns that mimic brain activity. Thus, they tried to show visual stimuli in the form of holographic obstacles, which the running mice tried to avoid actively.
The technology used to generate the holograms is called "optogenetics without 3D scanning with temporal focus" or 3D-SHOT. A liquid crystal display acts as a photographic negative, but for holograms. Using this negative, scientists mold the lasers in 3D patterns of their choice, inside the brain. Then, the laser pulses are fired every millisecond in bursts to maintain the hologram.
How did the researchers know that the mouse brain was effectively "cheated"?
"At the same time we used our holograms, we could see the neurons blinking," explains Alan R. Mardinly.
The scientists also recorded video footage of what they were seeing inside the brain of the rodents. The activated neurons shone fluorescent green, while the purple arrows indicated the laser light that activates them.
But it was not 3D-SHOT that caught the attention: "The ingenuity of the team led us to the advancement of the study: the ability to direct and fire specific neurons without causing neighboring neurons to activate.We knew that each neuron has its own distant target that you are trying to achieve, but unless you can enter and write a pattern in a neuron and not in the neighboring neuron, you do not have the ability to ask questions about what is happening and what these different patterns mean, "Oldenburg explains.
For some observers, the experiment invites comparisons with science fiction and fears that this technology will inevitably be used for mind control or emotional manipulation. The researchers reject this kind of thinking. First, just because in a mouse it can be done, it does not mean that in a human it does.
