Sixteen Experimental Investigations from the Harvard Psychological Laboratory - Hugo Münsterberg (best life changing books txt) 📗

limiting sensation

and then dies away during the relaxation phase. The sensations from

this positive muscle set have the principal place in consciousness

during the rhythm experience. The curve below the base line represents

the contraction of the extensors, the negative muscle set. The

contraction of the negative muscles reaches its climax very soon after

the maximum contraction of the positive muscles, in the contraction

phase. The sharp tension between the two opposing sets of muscles at

the limiting sensation may be made very apparent if the finger beats

the rhythm entirely in the air; in that case the limiting sensation

consists entirely of the feeling of a sudden increase of tension

between the positive and negative muscle sets. During the relaxation

phase the contraction of the negative muscles continues, but the

tension between the two sets grows less and less, for the positive

muscles are rapidly relaxing. At the highest point in the movement

either muscle set is exerting but very little strain; the condition is

represented in the figure by the approach of either curve to the

base-line; the amount of tension between the two sets is figured by

the distance of the two curves from each other.

 

[Illustration: FIG. 9.]

 

Assuming such a movement cycle, in which the tension between the two

opposing sets never comes to zero until the close of the series, it is

not difficult to arrange many of the facts of rhythmic perception

under the motor theory.

 

1. The feeling of rhythm is more definite as we proceed in a verse, or

a series of simple sound sensations. At first the cycle is not

perfectly adjusted and complete automatism established.

 

2. If an observer is listening to a series, and an unusually long

pause is introduced between two beats, there is always a feeling of

suspense or tension during the ‘lag.’ As long as the tensions are

maintained there is a rhythmic continuity; the feeling of tension is

the strain of opposition between the opposing muscle sets.

 

3. The continuity of the rhythmic series, whereby all the beats of a

period seem to belong to a single whole, is due to the continuity of

the muscle sensations involved and the continuous feeling of slight

tension between the positive and negative muscle sets; nowhere within

the period does the feeling of strain die out.

 

4. But at the close of the period we have a pause which is

demonstrably not a function of any of the intervals of the period.

During this pause the tension between the two sets ‘dies out,’ and we

have a feeling of finality. This gradual dying out of the tension is

clearly seen in the constant appearance of the cone-shaped final

syllable at the end of each nonsense verse.

 

5. The period composed of a number of unit groups (the verse, in

nonsense syllables) has a general form which suggests strongly that it

has the unity of a single coördinated movement. There is no more

reason for assuming a transcendental mental activity in the case of a

rhythmic period than in the case of a single act which appears in

consciousness as a unity. Undoubtedly the breathing is correlated with

the rhythmic movements and may be a factor in determining the verse

period. Meumann’s principal accent, about which a number of

subordinate accents are grouped, is characteristic not only of poetry

but of the simplest rhythms. At some point in the period there is a

definite climax, a chief accent; the movement ‘rises’ to that point

and then falls off. This is strikingly seen in nonsense verses spoken

with a heavy accent within the verse. The accent does not stand out

from a dead level, but the verse culminates at that point.

 

Unfortunately very little is known of the mechanism of so simple a

coördinated muscular activity as that necessary for a simple rhythm.

Sherrington[17] and Hering[18]have pointed out the primary character

of the grouping of the muscles in opposing sets and the reciprocal

nature of almost all muscular activity, but in a review of the work of

coördinated movements Hering denies any simultaneous stimulation of

the two sets and considers the question of the innervation mechanism

of opposing muscle-sets entirely unsettled.

 

[17] Sherrington, C.S.: Proceedings Royal Soc., 1897, p. 415.

 

[18] Hering, H.E.: Archiv f. d. ges. Physiol. (Pflüger’s),

1897, Bd. 68, S. 222; ibid., 1898, Bd. 70, S. 559.

 

That the connection between the positive and negative set of muscles

in a rhythmic movement is very close, and that the reaction is of the

circular type, is evident from the automatic character of all rhythmic

movements, and it is evident that the limiting sensation is the

primary cue in the reaction. Anything further is mere hypothesis.

Robert Müller’s[19] thorough criticism of the Mosso ergograph throws

great doubt on the present methods of investigation and invalidates

conclusions from the various curves of voluntary movements which have

been obtained.

 

[19] Müller, R.: Phil. Stud., 1901, Bd. 17, S. 1.

 

The curve of contraction and relaxation of a simple muscle is well

known and is not affected by Müller’s criticism. Its chief

characteristic, with or without opposing tension, is the inequality

of the intervals of the contraction and relaxation phases. As one

might expect, since a single set of muscles dominates in a rhythmic

movement, the typical rhythmic curve has the general character of the

curve of the simple muscle. The average values of the phases of curves

of simple rhythmic movement obtained by A. Cleghorn[20] from a large

number of observations with at least three subjects, are as follows:

phase of contraction, .44 second; phase of relaxation, .54 second. It

is very significant for a motor theory of rhythm that this general

form of the curve of rhythmic movement may easily be altered in all

sorts of fashions by unusual stimuli to the two muscle sets.

 

[20] Cleghorn, A.: Am. Journal of Physiol., 1898, I., p. 336.

 

While it is well recognized that a rhythm does not consist necessarily

of sound sensations, the ‘rhythmization’ of a series of sound

sensations in the ordinary perceived rhythms is a matter of great

interest. Ewald found strong reasons for believing that the ear is

peculiarly connected with the motor apparatus. The experiments of

Hofbauer[21] and Cleghorn[22]show that any strong stimulus to either

eye or ear modifies decidedly the reactions of coördinated muscles.

How shall we assume that the automatic movement cycle necessary to

rhythmic perception is set up when one listens to a series of sounds?

 

[21] Hofbauer: Archiv f. d. ges. Physiol. (Pflüger’s), 1897,

Bd. 68, S. 553.

 

[22] Cleghorn, A.: op. cit.

 

It must be assumed that any chance sound sets up a contraction in a

set of muscles, however large or small. If but a single sound occurs,

the phase of contraction in that muscle set is followed by a longer

phase of relaxation, and the musculature is passive as before; it may

be that the stretching of the antagonistic set of muscles weakly

stimulates them, and they then contract during the relaxation phase

and assist in restoring the original condition.

 

But if a second sound occurs toward the end of the relaxation phase,

before the tension is quite exhausted, the movement will be repeated;

the negative set of muscles will be more definitely stimulated, for

the activity will not have been exhausted when the second sound

occurs. If the sound continues to recur at regular intervals, the

movement cycle thus established will rapidly become coördinated. The

positive set in its vigorous contraction furnishes a limiting

sensation which becomes a cue for its own relaxation and for the

reciprocal contraction of the negative muscle set. The contraction of

the negative muscle set and the resulting changes in tension may

become in turn a cue for the positive set. The reaction is now of the

circular type and the process has become self-regulative, though

constantly reinforced by the recurring sound (which has become a part

of the limiting sensation of the rhythmic movement cycle).

 

But it is very probable that the second sound may not be timed so as

to come at the close of the relaxation phase in the set of muscles

roused; moreover, in almost all rhythms there are secondary sounds

occurring between the main beats. What happens when a sound occurs out

of place, early in the phase of relaxation, or just before or just

after the climax in the contraction phase? Does it make it impossible

to establish the coördination, or destroy it if already established?

 

Hofbauer demonstrated that a stimulus which appears in close proximity

to the limiting sensation, either before or after, always increases

the force of the reaction, so that such a slight displacement could

not affect the rhythm, which would quickly readjust itself. The

possibility of a stimulus occurring in the relaxation phase is of much

more importance for a motor theory of the initiation of a rhythmic

movement. Cleghorn made the stimulus occur at the beginning of the

relaxation phase. Instead of prolonging or reinstating the contraction

phase, he found that the stimulus _intensified the relaxation process

and shortened its period_. “The stimulated relaxation is not only

quicker than the normal, but also more complete; the end of the normal

relaxation is slow; … relaxation under the influence of the

stimulus, on the contrary, shows nothing of this, but is a sudden

sharp drop directly to the base line and sometimes below it.” A

comparison of the normal phases with the same phases, when the

stimulus occurs within the relaxation phase, follows:

 

Normal: Contraction-phase, .44 sec.; relaxation-phase, .54 sec.;

total, .98 sec.

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.

 

[23] Scripture, E.W.: ‘The New Psychology,’ London, 1897, p. 182.

 

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