483 



By means of antiplioncs every auditoiy sensation is precluded so that the observer 

 is entirely thrown back upon tactual sensations. 



When we select a favourable rate of rotation, say 1 or 2 revolutions per second, 

 subjective rhythmisation will soon reveal itself; at every time the observer will 

 perceive with greater stress the 2"^ or the 'i"i touch, just as occurs with auditory-, 

 and visual stimuli. It is also evident that with slow rates the observer will more 

 readily apprehend a 2 rhythm; with increased rates, however, there is a greater 

 aptitude for a 3-, or a 4rhylhm. 



After some practice the observer will be enabled to work up to a different 

 rhythm at every moment, either rising or falling. Suggestion imparted by his 

 surroundings is of very great influence, but with a special rate of successive 

 stimuli he generally selects a definite rhythm, most often a falling 2-rhytlnn 



( ■), or a falling 3-rhytlim ( — ^ ^). However, other more complicated rhythms 



may occur. 



Simple llioiigli tiiis experiment may he, il is a great help to 

 explain tlie nature of "subjective Rhjliiinisatiou", as il shows that 

 this plieiiOMienon is not restricted to audilory-, or visual seiisalions. 

 It prompis us to assume thai all sensory sliiinili, which liiltll certain 

 conditions, ma}' be perceived rhythmically. 



Let us tirst of all find an answer lo the question what subjective 

 rhythmisation really is. A periodi»- recurrence of "Betonungsunter- 

 schiede", "Iimerliche zusaumienfassung" (Meumann (2), and other 

 much used terms are merely jieriphiastic desigruitions of our ex- 

 periences, tiiey do iu)t, however, explain their genesis. Neither is 

 any explanation all'orded by the mental pictures of rhythmic move- 

 ments (such as dancing, the gallop of a horse and others), which 

 in subjective rhythmisation are often aroused through association 



(KOFFKA (3)). 



Introspection and the exact record of our ex|)erience, will have 

 to show us the way here. We, therefore, made the following ex- 

 periments; the observers were besides oursehes, 3 medical studeids. 



Experiment -. The observer is subjected to a regular series of auditory stimuli 

 we choose sound stimuli because sounds, indeed, are the better material for the 

 perception of rhythm). The stimuli are applied in succession at a ceitain rate, about 

 1 to 2 stimuli per second, that quick or slow rate being selected with which the 

 observer apprehends a certain rhythm most distinctly He is instructed to attend to 

 what he hears, and to record accurately what he experiences by soft laps coinciding 

 with every lick he hears upon a copper layer with a copper rod. As soon as the rod 

 touches the layer an electric current, attracting an electromagnet, passes through. 

 When the rod is raised again the current is broken, and the electromagnet returns 

 lo its original position. The electromagnet is provided with an inked pointer, which 

 records the up and down movements on a rotating kymograph. In the curve thus 

 obtained, the moment can be read at whicii the circuit is made (descending 



