Mydriasis pupil) or overactivity of the sympathetic nervous system (SNS). Pupil diameter also increases in reaction to cognitive tasks requiring memory and attention, and this phenomenon is used as an indicator of mental activation (‘arousal’) in psychophysiological experiments . Natural release of the hormone oxytocin can cause mild to moderate mydriasis. Parasympathetic fibers travel with cranial nerve III, the oculomotor nerve, to innervate the circular layer of muscle of the eye (sphincter pupillae). Damage to this nerve typically manifests itself as mydriasis, because the sympathetic supply to the pupil, which causes mydriasis, remains unaffected, and therefore unopposed. Multiple central nervous system
Normally hyperbolic invariant manifold the unstable bundle and denoted "E" and "E", respectively. With respect to some Riemannian metric on "M", the restriction of "Df" to "E" must be a contraction and the restriction of "Df" to "E" must be an expansion, and must be relatively neutral on formula_4. Thus, there exist constants formula_5 and "c" > 0 such that and Normally hyperbolic invariant manifold A normally hyperbolic invariant manifold (NHIM) is a natural generalization of a hyperbolic fixed point and a hyperbolic set. The difference can be described heuristically as follows: For a manifold formula_1 to be normally hyperbolic we are allowed to