Sleep

And the mome wrathes outgrabe..

Consciousness has two faces- (i) waking/memory acquisition and (ii) sleep/memory consolidation.

Sleeping aspect of consciousness
Sleep is not a lack of consciousness, but one of several special conscious sub-states the brain uses to do its work. Sleep's purpose is to ensure (procedural and declarative) knowledge acquired during waking ('on-line') periods is consolidated during off-line periods*. 

This is where the TDE architecture proves quite useful- it represents a classic case of good theory 'carving nature at its joints'. The boundary between TDE level 1 (embodied computational level) and TDE level 2 (situated computational level) is
(a) structurally associated with the eyes
(b) procedurally associated with saccadic motion of the eyeballs
(c) cognitively associated with visuospatial perception
(d) matches the neuroanatomic division of ascending and descending reticular activations systems (ARAS and DRAS).

TDE theory posits that the brain is ultimately an embodied computer, and that all of its 'software' processes are semantically grounded in somatic motions (reflexes and postures) and their matching proprioceptions (perceptions of limb, head and torso configurations derived from from pressure, velocity and acceleration inputs). John Hughlings-Jackson, famous 19th Century neuroscientist and foundation editor of the journal, Brain, was the first person to recognize that the cerebrum and cerebellum performed different, but complementary tasks. While the cerebrum managed movements of the individual in space, the cerebellum managed bodily motions in time. Outside the skin, the cerebrum organises spatial movements, whereas inside the skin, the cerebellum organises temporal motion.  The choice of the words 'movements' and 'motions' is due to Hughlings-Jackson himself. 

The eyeballs perform a unique and hybrid function. Like the limbs, they are physical articulators- like arms, they can grasp objects, like legs they can move across distances. However, what is moved is not a physical output device (such as a gripper, like a hand or clamp, or a physical treader, like a foot or wheel) but a virtual input, a sampled window, a targeted representation. They are a hybrid of an articulator/locomotor appendage, and an input channel or sensor. 

Therefore, eyeballs operate physically within the body domain, like any other limb, but they also act virtually in the outside world, because that is where the information they gather comes from. That is why they are managed physically by the cerebellum, in terms of saccadic motions, but virtually by the cerebrum, in terms of situation images.  Eyes are duplex information channels, being both effectors and affectors.

*I discussed my research findings with acclaimed Sleep Scientist Professor Leon Lack, one of the original 'founding fathers' of the project in 2011.

In the figure below, the three levels of the TDE are shown, take particular note of the boundary between TDE1 and TDE2.  The diagram is a hybrid of the GOLEM hierarchical memory diagram, and the TDE-R fractal architecture diagram, therefore it is called the TGT diagram, where TGT is an acronym for TDE/ GOLEM Theory. Like the GOLEM, the TGT has two columns, the left-hand column represents the motor/output/conceptual channel, while the right-hand column represents the sensor/input/perceptual channel. But like the TDE-R diagram, the TGT has three rows, corresponding to the TDE's three fractal levels.

The beauty of the TDE explanation for the various sleep modes is that it explains inter alia paradoxical sleep so elegantly. There can only be four states of waking (+) or sleep(-), taking the first two TDE levels together as a unit. These are  {(TDE1+, TDE2+) , (TDE1+, TDE2-) , (TDE1-, TDE2-) , (TDE1-, TDE2+) }. With confidence, we can replace the terms TDE1 with 'body',  and TDE2 with 'mind'*.

Logically, then, we would expect each of these sleep modes to correspond to their matching neural activation patterns:- { (DRAS+, ARAS+) ,(DRAS+, ARAS-) , (DRAS-, ARAS-) , (DRAS-, ARAS+) } 
From the slides below, we can confidently see that the pairing of DRAS with body arousal, and ARAS with mind arousal are completely reasonable conclusions to make. 

*TDE3 fits into the scheme seamlessly as an equivalent to 'self', meaning one's narrative self, the goal-oriented agent of episodic knowledge.