1921] on The Electrical Expression of Human Emotion 287 



hypnotic state, and in the state called " trance." We are familiar 

 also with innumerable objective signs of such subjective phenomena 

 in the shape of descriptions of dreams and in the behaviour of sleep- 

 talkers and sleep-walkers, and, above all, in the extraordinary cases 

 of spiritualistic mediums. These last stand highest in the scale of 

 sensitiveness. 



The relative magnitudes of response to real pin -prick and to a 

 fictitious pin-prick vary with different people under different condi- 

 tions, but in general they may be divided into two categories, whom 

 we may call positives and imaginative^. 



Positives — in whom little or no disturbance is caused by the 

 threat of a pin-prick, and a real pin-prick is required before any 

 response takes place. 



Imaginative^ — in whom a large response occurs to the threat — 

 larger, it may be, than the response to the real fact. In not a few 

 of this imaginative class it is almost impossible to take a pure 

 observation of response to fact, for they begin to respond as soon as 

 the operator makes the slightest movement, or else the response is a 

 large one, compounded of fear followed by fact. Here is a 

 confirmatory experiment in evidence of what may be characterised as 

 a dwindling fear and its revival by fact. [Experiment.] 



All men (and, judged by their behaviour, animals also) are more 

 or less imaginative. The kind of diagram you have just seen would 

 represent the responses of nine out of ten of my present hearers to a 

 series of threats with a real shock interpolated in the series. Many 

 of us had an opportunity a few years ago of studying upon our friends 

 and upon ourselves the signs and symptoms of fear during German 

 air raids upon what they called the fortified city of London. The 

 noise and disturbance occasioned by these raids, the false alarms and 

 the warnings by maroons and sirens, afforded a unique opportunity 

 for the exact galvanometric study of the emotions aroused by various 

 kinds of noises. From the purely scientific point of view the 

 opportunity could not be neglected of studying the psychophysical 

 phenomena brought to our doors — phenomena that could not be 

 expected again within the same lifetime. So from the air raid of 

 September 21, 1917, to the last and most prolonged visit of 

 Whitsuntide, 1918,1 enlisted the services of volunteers to sit quietly, 

 connected by wires to a galvanometer, and on two occasions I had 

 sitters arranged in connection with recording apparatus which was 

 set going a few minutes before the noise began, so that the emotive 

 response during the whole affair was recorded. Let me show you 

 two or three photographs (Figs. 2 and 3). 



These photographs are not merely of interest on their human side, 

 but also have this definite scientific value, that they afford measured 

 records of the largest emotive responses that I have ever witnessed. 

 The responses commonly observed in the laboratory are at most 

 10 per cent, changes ; these air-raid responses have been at least 



