Changes in pulse, breathing, and steadiness under conditions of startledness and excited expectancy.

Abstract

The state of startledness was produced in normal humans by blowing a motor horn, and of excited expectancy by warning the subject that he was shortly to receive a severe electric shock. In both states the author observed slowing of the heart with an increase of amplitude; momentary checking of the breathing followed by acceleration and increased amplitude. Steadiness, as tested by placing a pencil in a hole so that it would not touch the sides, seemed to show some increase after the noise, whereas in the state of excited expectancy the subject''s accuracy was diminished.