Quote Originally Posted by zoth00 View Post
The idea that REM atonia completely paralyses you is untrue, and since SP resembles/equals REM atonia, then probably the same could apply to it. Even though I disagree with Auron regarding REM atonia being a type of SP (because if REM atonia is the natural process, then the anomaly which is SP is actually turning the exception as the name of the category), I think it's important that we are careful with "breaking SP or being unable to move". You can move during REM atonia, or at least have minimal muscular voluntary control, according to this article which presents tests made by LaBerge. Presenting the specific information:

Figure 4. Morse code communication from the lucid dream. Evidence of voluntary control of other muscle groups during REM was found by LaBerge, Nagel, Dement, and Zarcone (1981) while testing a variety of lucidity signals. We observed that a sequence of left and right dream-fist clenches resulted in a corresponding sequence of left and right forearm twitches as measured by EMG. Here the subject sends a Morse code signal with left and right fist clenches corresponding to dots and dashes, respectively. Hence the message translates as "SL" (... .-..), the subject's initials. Note that the amplitude of the twitches bore an unreliable relationship to the subjective intensity of the dreamed action. Because all skeletal muscle groups except those that govern eye-movements and breathing are profoundly inhibited during REM sleep, it is to be expected that most muscular responses to dreamed movements will be feeble. Nonetheless, these responses faithfully reflect the motor patterns of the original dream.
And from that same source which you conveniently left out...

These and related studies show clearly that in REM sleep, dreamed bodily movements generate motor output equivalent at the supraspinal level to the patterns of neuronal activity that would be generated if the corresponding movements were actually executed. Most voluntary muscles are, of course, paralyzed during REM, with the notable exceptions of the ocular and respiratory muscles. Hence, the perfect correspondence between dreamed and actual movements for these two systems (Figs. 1-3), and the attenuated intensity (but preserved spatio-temporal pattern) of movements observed in Figure 4.

These results support the isomorphism hypothesis (Hobson et al.) but contradict Solms's (1995) notion of the "deflection" of motor output away from the usual pathways, and his speculation that it isn't only the musculo-skeletal system that is deactivated during dreams, but "the entire motor system, including its highest psychological components which control goal-directed thought and voluntary action." (Solms 1995, p. 58) I believe Occam's Razor favors the simpler hypothesis that the motor system is working in REM essentially as it is in waking, except for the spinal paralysis; just as the only essential difference between the constructive processes of consciousness in dreaming and waking is the degree of sensory input. See LaBerge (1998) for details.
Ok, that's all I want to add, there seems to be a real misunderstanding in the information you provided regarding the nervous system and the impact of paralysis on the skeletal system and actual movement (not just muscular twitches). Ok...done here.