Public information refers to knowledge and data that we can measure objectively, and that science can deal with.
Private information refers to stuff inside the body that we can introspect and speculate about, but that cannot yet be measured objectively with instruments and machines.
The boundary moves from time to time as we invent more clever machines to take measurements, such as functional MRI.
The boundaries are meant to clarify what we take as known or knowable, in the sense that we can observe and measure it in some objective or scientific fashion. The knowable stuff is on the public side of the boundary, and the unmeasurable stuff on the private side of the boundary. We are talking about measurement during normal activities.
The first boundary deals with action. The position of bones and joints is knowable, since we can attach markers and record their positions. The muscles attached to these bones is in a grey zone. We can examine and measure them anatomically. We can guess at their relative positions, but we cannot easily measure their length, etc. during movement. Neural signals to the muscles are on the private side of the boundary, in the sense that we cannot measure and record them during free movement.
The second boundary deals with visual perception. The image going into the eye is on the public side, since we can mount a camera and record it. The neural information coming from the retina is on the private side.
This investigation explores the private side. It treats neural signals travelling over nerves as analogous to binary electrical information flowing over wires. The investigation focuses on the information processing, on requirements, and on possible prototypes for simulating this information processing.
Working on the private side limits experimentation with real-time processes. Instead we are building a sequence of simulations that hopefully become more and more competent to do analogous information processing with analogous public-side inputs and public-side outputs.