"…ties that bind the physical and metaphysical. Remember, you are three parts: body, mind, soul. We’ll come back to the third one later, as it is the most vague of the set.
The classification of the second and perhaps most misunderstood of the three parts is difficult. The ‘mind’ component, as we call it, is neither the firing of neurons in the brain (for this is physical) nor the actual root of self-awareness and discernment (for this is spiritual). Nevertheless, it is still an important component of thought for most sentient beings, and is, as we’ve already noted, the requisite component of all psionics and what for better or for worse is called ‘mind reading’, so the name stuck. Personally, I would have called it something less vague.
Admittedly, non-vague terms are hard to find. The ‘reformist’ element of the Cult of Kizak call it the root of magic, but this is only partially true; magic is a series of attempts to manipulate this part but is not the part itself, and in any case magic has its true roots in some particularly bad parts of the spiritual realm. The Tor Yvresse refer to the whole mindscape as Warp and the human or sentient element as a being’s ‘reflection’ in Warp. This hits somewhat closer to the mark, but given that they made the connection as a result of some tinkering with FTL drives, the term is perhaps biased. This is probably the best-known variation on the colonies, but while the technology is efficient such interpretations are very dangerous: as we shall see, the common curse “take a warp jump to hell” isn’t just an expression (See chapter 12). So I must begrudgingly accept “mind”. So what is this ethereal substance?
There is a layer of reality that exists parallel to own, inexorably bound to it. For each location in the physical world, there is a corresponding location in this ‘mindscape’. They are not quite scaled accordingly: as both the personal teleporters developed by Lady Secondary Haskalah of Chiron and the FTL-drives of Tor Yvresse prove, the mindscape is ‘smaller’ than material space, at least when something from the physical universe is shoved into it.
Into this layer a vast majority of all living beings in the universe perpetually pour energy. Each and every one of us, every pet cat or bat, every mushroom, every blade of grass has a “signature”, a pattern of energy exuding from the mindscape’s equivalent to their location in the material world. The signatures of sentient beings are larger than those of nonsentient beings, and it is these signatures that we call the “mind”.
What goes into this? Fortunately for medical ethics, any sort of actual dissection is quite impossible. To draw a diagram of one would be quite difficult, as the physics of the mindscape are not exactly identical to those of the physical world. Indeed, it is quite frustrating not to be able to take a snapshot of something that is as much a part of us as, say, our arms and legs. What what psionic analyses we can do indicate is that they do not even always share the same basic shape. Sometimes a person’s mind-signature is a relatively amorphous blob. Sometimes it appears identical to the physical form of its owner. Sometimes it resembles instead their idealized perception of themself, or their worst fears about themselves. One colleague of mine, for an extreme example, once suffered from withdrawal after escaping a drug addiction and believed himself at times to be covered in ravenous arachnids. A particularly psionically attuned co-worker who worked one office away from him complained vociferously to me that she was haunted by images of a gigantic black spider whenever he was near. It was this form that his mind-signature had taken, so driven was he by fear of this very thing. I am told that he has since recovered.
As to the “anatomy” of the mind-signature, it is from here that it gets its name: its energy matrices contain active thoughts, memories, data, and emotions, in a mirror of the functions of the physical brain, with the exception that “motor” components are notably lacking, as are those associated with physical sensation. An entirely different, parallel set exist instead, associated with the motion and sensation of the signature itself.
The only really startling revelation here is that mind-signatures are mostly junk! The mental components or ‘core’, the vital organ that does normal work typically constitute less than one percent of the signature as a whole. The rest is tossed in as an afterthought, the result of a process that is from what we’ve seen thus far hideously inefficient. The fact of interest- and what, dear reader, you probably picked up this book to find out about in the first place, only to be faced with a massive desert of my stuffy prose- is that the rate of inefficiency varies from individual to individual. Some people are more inefficient than others, pouring in many times more energy than normal. Some people are more efficient, having far less energetic signatures.
It is from this very fact that the spectrum of psionic talent arises.
Those individuals whom we call psionically talented or gifted or just ‘psychic’ (a misnomer) have larger and more energetic mind-signatures than is normal. This is not because the functional mental portions of their signatures are somehow better. The belief that psionic talent and high intelligence naturally accompany each other is more a product of bad holodramas than actual fact: Many geniuses have very little psionic talent, and many massively psi-gifted individuals are mentally ill or impaired. Rather, a greater degree of psionic talent means a larger clump of “junk” signature. The more of this one has, the greater the ease with which he or she can learn and apply the traditional abilities of the psyker, which we have already covered to some degree: The ability to manipulate the material to some limited degree, the ability to analyse the signatures of others (and ergo to resist such analysis), and the ability to sense nearby signatures.
This only applies to ease. Anyone with the right training can learn any of these skills. “Psychic” is a misnomer because nearly all sentient beings are “psychic”. The difference is that for those of us born on the lower ends of the spectrum, learning these things takes years of careful study and meditation, while those born higher on the scale can master them with relative ease.
-Chapter 4, R. Penteleimon, "The Open Mind (2006 12th edition)