IN EARLIER investigations1 it was found that (1) reiterated elicitation of a single autonomic reflex or (2) hard work by which the subject was generally fatigued resulted in disintegration of central autonomic mechanisms of control. When the pupillary reflex to light was fatigued and finally exhausted by repeated stimuli, two related sequences of events occurred:
In the periphery, a gradual, although rhythmically interrupted, disintegration of the reflex shape. Certain types of reflex shapes appeared and were described as shapes of slight disinhibition of contraction, the tonohaptic reflex, W- and V-shapes, sluggish and inextensive contraction, prolonged latency periods, and absence of the reflex.
In the centers of autonomic control, corresponding processes of disintegration, the sequence of which was expressed in a general law: "All nervous fatigue is central in origin; the sympathetic centers fatigue prior to the parasympathetic centers, the cortical prior to the subcortical."
All fatigue shapes which, transitorily and
OTTO LOWENSTEIN, IRENE E. LOEWENFELD. TYPES OF CENTRAL AUTONOMIC INNERVATION AND FATIGUEPupillographic Studies. AMA Arch NeurPsych. 1951;66(5):580–599. doi:10.1001/archneurpsyc.1951.02320110045004