The Relation of Muscular Tonus and the Patellar Reflex to Mental Work

Abstract

The fact that intellectual effort is accompanied by an increase of muscular tonus was demonstrated by one of us in 1921 (1), the method employed being the registration, by means of a highly magnifying optical lever system, of slight displacement of a relaxed limb. It was found that those muscles which were in a state of postural tension increased in tonus during intellectual work, whilst the fully relaxed antagonists remained unaffected.