I cannot presume to speak for my cat!
Nor indeed any other animate, including prokaryotic microbes, nevertheless i venture this as being at least utilitarian if not precise.
Within the Human aural system is a group of structures and cells with the main purpose, as far as we can tell, of coordinating kinaesthetic action. The adage" we have to start somewhere" applies to our organism, and since we may start anywhere there is no way of determining position, orientation, direction except relative to a close and ever present community of communicating organisms. Such a community we may call a recognisable stucture, because it is self referential, interactive and self conformable.
There are many other attributes which may present themselves later , but the main point is that this description of a structured community applies to this "collection" of cells.
This collection of cells locates in the inner ear and is called the vestibular system, and the chief purpose is to collate a network of derived cells into a complete kinaesthetic system. The tracking of this structure through cell development would be instructive, but as yet i have no data on that. However, the Peripheral Nervous system is under investigation and these investigations may yet reveal the data.
Suffice it to say that the structure within the aural system is as close to the brain as any of the other primary distinctions in the Nervous system, and is part of a very interesting structure of sensory inputs, and processing centres.
It is fair to say that the aural system is unique in its position within the structure of the sensory mesh and consciousness, because the vast majority of sensors in the developing organism we call the body are embedded in a mesh of communicating cell structures which have a "local significance. some call interioception. The fewer specialist sructures in the head form a group with "universal" or environmental significance, some call exterioception. Of these the gustatory system in some sense is the crossover from interior to exterior perception, involving as it does both taste and smell, and the next to that is the aural system involving both touch and pitch and orientation.
Because of the sense of orientation the whole organism "grounds" itself into interior and exterior, and action to interact the "division".
There is another structure, the gut, to which the gustatory system is heavily linked, which also drives interaction between interior and exterior, but without the coordinating role of the aural system it has no external directional significance.
Why have i left out the eyes? You will see why as i progress.
The Central Nervous system is the most obvious structure within the neural networks, so it took time to explore the relative importance of the Peripheral Nervous system. In any case we need not concern ourselves with various conceits that some have held as dogmatic "truth", but merely observe that the complexity of the cybernetic system response makes clear that a single central structure was insufficient to explain all our bodily reactions and functions.
We must also pass over opinion, not well founded as to the relative importance of certain structures within the organism we call a body, and merely observe "thank god it is so adaptable, responsive to change and damage and robust"!
There are many structures and arrangements some in arrogance have deemed to be of little worth, and others which some have given too high significance to,but nevertheless there is a growing appreciation of the cybernetic importance of all of it and the reactive nature of so called redundancy.
I merely observe that the PNS links in to the aural system most closely enabling every muscle motion in our entire body, including that of the eyes, to have a common reference frame.
Science has always progressed as optics has progressed, and consequently geometry and optics constituted the main preserve of scientists for a good many centuries. Science was therefore a highly visual field, and alchemy was not considered science until it could be described in this visual way. Music also was not considered science, and yet it is foundational to science and mathematics. These "odd" distinctions were made according to the opinion of one authority or another, and thus scientific progress was hindered by overbearing opinion. Alas, it was, and is ever thus.
My advice: " Trust no one!"
The fundamental contribution of the kinaesthetic system is proprioceptive spaciometry. The semi-circular canals so called, but rather more accurately the trochoid canals, provide a sense of orthogonal rotation. There are some directional switch sensors which confirm the orientation of the head versus the neck and body, and this determines orthogonality within the spaciometric system.
Thus rotation and relative orientation sensors are the fundamental processing system i use to make spaciometric sense of the world. There is no absolute orientation, or rotation, their is for me only self referencing orientation and self referencing rotation. This is ideal, because i have to adapt to any and all situations to survive.
Sensors distributed around my growing organism provide me with orientation information via comparative processing and feedback and feed forward processing. This orientation is always proprioceptive:It gives me the relative positions of joints within my body. The specific trochoidal sensors in my aural system provide me with rotational information, and to this i add torque, twist and torsion data from sensors to again give relative joint positions.
n top of, grafted to this proprioceptive "skeleton" is the exterior information. These are combined by cerebral cortex processing to provide me with an instant on, "now", experiential continuum. Furthermore, the amygdalla combines these experiential sequents into affective memory structures which are stored throughout the organism in every structural configuration that my organism can adopt.
Thus i have a kinaesthetic memory, a visual memory an auditory memory etc, andone ought not to limit memeory storage, or signal processing to the brain or CNS processing.
This has consequences for transplant surgery. In transplanting an organ surgeons should be mindful that they are also transplanting memory information. It usually is the case that organs are transplanted as quickly as possible with as little disturbance as possible, thus maximising the integrity of the information stored in that structure.
It may be possible to "wipe" the organ of stored memory data, but this would require research, as i suspect that the memory information is not simply stored in the tissue electrically,but also chemically and biologically at the level of cell processes.
Left Forward Up Down Back Right are the natural orthogonal orientations we adopt. That is to say that we distinguish by rotation these 6 orthogonal orientations. The cool thing about them is that by rotation they leave one orientation unchanged. This is the nature of orthogonality. The unchanged orientation is usually picked ou as the "axis" of rotation.
We clearly can rotate around a centre in a way that does not preserve orthogonality, and this we usually find bewildering. This is why the orthogonal sensors within me have direct influence on my perception visually. Rotation is my primary sense but orthogonality is expected and demanded by the system as a starting point to "ordered" perception", thus the orientation sensors are immediately and homeostatically engaged. As soon as i can establish orthogonal rotation in one axis i can begin to compute rotation in space in terms of Left to Right, Forward to Up to backward to Down.
Culturally we have a bias to Left and right, so in rotation terms we do not need to mention going through forward and backwards, but as soon as i leave the familiar designations i have to specify more precisely the motion sequence, or the motion trace.
F U L R F B B D
The diagram shows 8 quadrants, and the natural subjective measure to make to give a position in a quadrant is an rotation measure . Because this is so natural one is immediately lead to trigonometric descriptions of spatial dynamics.Thus i see that a natural reference frame arose from the use of the right "angled" triangle and its trigonometric properties.The only improvement to make on this natural system is to enclose it within the unit sphere to enable "angle" measure.
From this natural system i can easily derive all other reference frames. I also have several choices as to notation and nomenclature, and parameterisation.
Fundamentally, however i have to take this reference frame as a stripped down to the bare bones version or analogy of consciousness. I have to view it as a tool that extends my conscious ability and action to measure beyond myself to an external collaborative world.If i cannot agree a reference frame with someone i perceive as other then communication fails.
Now perception of other derives from the experience of not being able to know everything. In particular, not being able to know what is behind a screen. "Peek a boo" is an essential socialising tool for a developing child, otherwise it has no idea that others are not part of its imagination.