How does transorbital alternating current stimulation work?
We can think about the brain as a kind of amplifier. With its neuronal networks it can extract, amplify and then “translate” or interpret the neuronal signals coming in from the retina. Then the neuronal impulses get transformed into conscious visual experience. This amplification is important for normal vision but is particularly valuable when vision is impaired and fewer neuro-signals reach the brain. The brain has a wonderful talent for making the best use of reduced information. It works like night goggles to amplify even the lowest level of luminance – though just as with night goggles, this does not work if there is no residual light. The brain is a super talent when it comes to amplifying information and extracting meaning out of it. It does this with its many neuronal circuits that support different functions and are connected in time and space with each other. This is called synchronization. Only with a healthy ability to synchronize can the brain support the coordination of all its parts and support conscious vision.
This figure illustrates how this might work. Let us use the shape of “waves” to demonstrate how neuronal networks continuously oscillate; up and down, up and down. If they all do this at different times, the network of all the oscillations is desynchronized, and, when added up, these waves may cancel each other out. However, if they all oscillate at the same time, following the beat of the same tune, then they can add up to one big wave.
Now let us consider a small retinal signal arising as a single wave from a partially damaged region of the optic nerve and traveling toward the brain. It is not strong enough to force itself through the desynchronized brain. The signal will not be amplified, so it gets lost in translation. No vision. But when our tiny retinal signal meets synchronized brain activity, then all the waves can add up to a larger “tidal wave.” Now the visual signal is sufficiently amplified, and it gains enough strength to produce a visual perception. This is how the brain can make more out of less!