Patterns of muscular activity during 'mental work' and their constancy.

Abstract

Muscular action potentials were recorded from locations on 3 limbs from 2 groups of subjects while at rest and while working arithmetic or learning problems, under "normal" conditions, and under instruction to keep the right arm relaxed. Under both work conditions there was increased muscular activity in all parts. Under normal conditions this tends to focalize in one part and show a decreasing gradient for parts remote from this. Instruction to relax the arm during work produces a degree of relaxation in that arm which was also extended in lesser degree to the other parts studied. Muscular activity tended to increase as the task progressed, and showed a different intensity and distr. for each of the tasks studied.