People 50 years ago would have said that about people who aimlessly slide their thumb up and down a glass screen on a device the size of a deck of cards.
I have no idea how that works with AR overlaying monitors on a physical worldview. So you're writing something overlaid on the view around the coffeeshop? The idea of AR is more to give a HUD that provides information about what you're looking at.
AR is commonly used to insert solid objects into the real world. See Pokemon Go and most HoloLens games. And the HoloLens app where a virtual dog lives in your house.
HoloLens is not able to render opaque objects. They always have some level of translucency, and the darker the colour of the object, the more translucent it is.
LTP is only one mechanism. Neurons vary their responses in multiple ways, usually some form of receptor protein modification. But again, this is one mechanism of many.
