With stim.: Contraction-phase, .47 sec.: relaxation-phase, .30 sec.; total, .77 sec.
It will be noticed that the total time of the movement cycle is reduced. One may then assume that a sound which occurs too early to become a factor in the limiting sensation, functions as a stimulus to the relaxation process and shortens the interval between the limiting sensations. Thus the movement cycle would be modified, but not destroyed. It is impossible to say just how the relaxation process is affected, and Cleghorn's own conclusions are open to criticism in the light of Müller's comments on the method. The simplest assumption would be that the stimulus acted on the negative set of muscles.
E.W. Scripture[23] objects to such a 'tonus theory,' because some subjects regularly react before the signal. But in no case in the published records to which he refers is the error more than.05 sec. either before or after the signal. The investigation of Hofbauer shows conclusively that in such cases the effect of the external stimulus simply fuses with the limiting sensation. Scripture overlooks the automatic character of the rhythmic movement.
There is a striking difference between rhythmic movement from unit group to unit group within a period, and movement from period to period (i.e., from verse to verse of nonsense syllables). Each foot is simply the repetition of the movement cycle; all the tensions are maintained, and each foot is an integral part of a larger act. At the close of the period (verse) the active tensions die out, either because of the introduction of some unusual stimulus which causes the positive muscle set to strike a heavy blow, and abruptly upset the balanced tensions, or because a pause of indefinite length ensues in which the tensions die out. This is the process which we call 'finality.'
In the stanza there is evidently a different type of unity from that in the single verse. When we hear the first verse of the stanza, we do not know what the verse whole is, until the finality factor or the verse pause is reached, at its close. Then the verse has a certain definite cumulative effect, a synthetic effect which results from the echoes of the various movements and the total effect on the organism. One may call it the tetrameter feeling. The verse pause may vary within large limits, but after a few verses there is a definite scheme, or 'Gestaltqualität,' which represents the verse unity. It is some sort of a memory image, which functions as a cue to the motor process. This motor image, set of strains, or whatever it be, is more than a mere standard by which we judge the present verse. The memory image fuses in some way with the living motor process. The preceding verse affects the character of the following verse. An irregularity, easily noted in the first verse, is obscure in the second, and not detected in the third verse, when the verses are identical.
The experiments of Hofbauer and Cleghorn, and many facts about the unit groups themselves, make it evident that the function of stimuli, during the movement cycle, varies with the position of the stimulus in that cycle. This offers a possible explanation of the striking peculiarities of the unit groups. The iamb [\/ _'] and the trochee [_' \/] should be quite alike for a general synthesizing process; but not only is the experiential character of the two quite unlike, but the ratio between their intervals is entirely different.
A number of measurements by different observers show that in the iambic foot the unaccented syllable is proportionately much shorter than the unaccented syllable in the trochaic foot. It is very easy to beat a simple up-and-down accompaniment to a series of simple feet of nonsense syllables; in the accompaniment the bottom of the down stroke, the limiting sensation of the movement cycle, coincides with the accented syllable of the foot. It is not an unwarranted assumption that such a fundamental accompaniment represents the fundamental movement cycle of that rhythm.
During the present investigation several observers were asked to determine at just what point in the fundamental movement the unaccented syllable occurred, when the subject gave a series of nonsense syllables. In the fundamental accompaniment the excursion of the hand and arm was at least.4 meter. Four subjects were thus tested, and the results were uniform in the case of all the simple types of unit groups.
In the case of the iamb the unaccented syllable occurs at the top of the movement, at the very beginning of the contraction phase (A, in Fig. 5).
In the case of the trochee the unaccented syllable occurs in the first third of the relaxation phase (B).