MUSCLES OF THE HEAD.
1st. Muscles of _mastication_; _masseter_, its form, its share
in the physiognomy (character of firmness, of violence);
_temporal muscle_. 2nd. Muscles of expression; nature and
special mechanism of the muscles of the _skin_; object
of their study (expression of actual passion, momentary
and not characteristic of the subject).--History of the
question.--Leonardo da Vinci, Le Brun, Camper, Charles Bell,
Lavater, Sue, Humbert de Superville.--Particular interest of
the drawings given by Humbert de Superville (“Unknown Signs of
Art”).--Duchenne of Boulogne and the experimental method applied
to the study of physiognomy.--Darwin (physiognomy from the
philosophical point of view, and evolution).
The muscles of the head with few exceptions occupy the anterior region
of the head and more particularly the _face_. They are divided into two
very distinct classes--1st, the muscles which serve for _mastication_
and move the lower jaw; and 2nd, the muscles which, under the influence
of emotion, modify the traits of the countenance and serve for the
expression of the emotions. We call these the _muscles of expression_.
The muscles of mastication present the general arrangement that we have
already met with in the various muscles of the trunk and limbs. They
are attached to the bones, and they have fleshy bellies, more or less
thick, which swell up in contraction, and are marked by prominences,
just as the contraction of the biceps is shown by the prominence it
produces on the anterior surface of the arm. The muscles of expression,
on the contrary, present a different type. These are muscles of
the _skin_, which move the skin and not the parts of the skeleton;
therefore their fleshy parts are in general very slender, and their
contraction is not marked by any local swelling corresponding to the
fleshy body, but only by change in place and form of the folds and
membranous structures of the face (eyelids, lips, etc.). We will first
study the muscles of mastication.
_Muscles of mastication._--The muscles which move the lower jaw are
inserted into the ramus and angle of the bone. Those on the inner side
of the jaw are the deeply placed _pterygoid_ muscles (so called because
they arise from the pterygoid process of the sphenoid bone). We need
not dwell on these muscles here, for they are deeply hidden in the
zygomatic fossa of the head, and are not visible in any part on the
surface. Those on the outer side are inserted either into the ramus
and angle of the bone (masseter muscle) or into the coronoid process
(temporal muscle).
The _masseter muscle_ is a quadrilateral fleshy mass (12, Fig. 88)
of which the upper attachment arises from the zygomatic arch (Fig. 56),
and the lower attachment is inserted into the ramus and angle of the
jaw. The anterior border of this muscle is thick, and in thin subjects
forms a prominence, in front of which the cheeks are sunk so as to
produce a more or less marked depression. In contraction the masseter
raises the lower jaw and brings it into contact with the upper, against
which it presses strongly. It would be superfluous to dwell here on
the part this muscle plays in mastication. It is more important to
remark that during violent emotions, or even when we accomplish a
powerful effort, we involuntarily clench the jaws. Contracting the
masseter, therefore, in anger, menace, and in the strong expression
which we characterise commonly by saying that the subject grinds
his teeth, we see the masseter shown in the form of a quadrilateral
prominence on the side of the face. Therefore the accentuation of
the form of the masseter contributes to give to the physiognomy an
energetic expression, and generally that of brute force.
The _temporal muscle_ (4, Fig. 88) occupies the entire extent of the
temporal fossa of the skull (Fig. 56); it arises from the bones that
form that fossa and from an aponeurosis which, arising from the borders
of the fossa, is attached to the upper border of the zygomatic arch,
so as to form a species of cover (_temporal fascia_) to the fossa
in question. From these multiple points of origin the fleshy fibres
converge below and form a strong tendon which embraces the coronoid
process of the inferior maxillary bone (25, Fig. 56), into which it is
inserted. This muscle raises the lower jaw, but as it is shut up, so
to speak, in a close space (temporal fossa and aponeurotic cover) it
does not show during its contraction a remarkable prominence in the
temporal region; nevertheless, in a person performing the movements
of mastication we see the skin of the temple, above the zygomatic
arch, slightly raised in a series of rhythmical movements; these
movements alone show externally the contractions of this muscle during
mastication.
_Muscles of expression._--From what we have already said respecting
the peculiar arrangement of these muscles of the skin, it is easy to
understand that their study must be undertaken in a totally different
manner from that of the muscles of the skeleton. We do not seek so much
to define the form of the fleshy masses as to trace the direction along
which each muscle exercises traction on the skin. Given the bony or
cutaneous attachments of the muscle, we must observe the direction in
which it acts, and so define the form of the folds or wrinkles which it
causes on the skin, and ascertain what facial expression is acquired
by these changes. Before we enter into these details, it is necessary
to glance rapidly at the history of this particular question of human
physiognomy, and then to consider the method by which its study should
be undertaken.
First we must remark that we study here, with regard to the muscles of
the face, _physiognomy in a state of action_--namely, the characters
that affect the features at a given moment, under the influence
of a passionate movement which causes (it may be) the involuntary
contraction of one of the numerous muscles of the skin. Indeed,
we may almost assert that the muscles of the face might be given
names associated with mental states--_attention_, _pain_, _menace_,
_laughter_, _sorrow_, _contempt_, _disgust_, &c. But we cannot pretend
to study physiognomy in a state of repose, or to learn by the normal
and permanent accentuation of certain of these traits the character of
the subject and the passions that most frequently disturb him.
Doubtless, these two studies have numerous points in common; it is
easy to admit that, in a subject who is governed by one prevailing or
overpowering emotion, such as suspicion, grief, or pain, the permanent
or frequently repeated contraction of the muscles which correspond to
these emotions can definitely mould the character of the face, so as to
leave imprinted on it in a permanent form the sentiments that govern
the mind.
But this analysis of the character of a subject is a very delicate
study, always very uncertain, and admitting of philosophical
developments which would carry us far away from the domain of anatomy.
On the other hand, the determination of characteristic expressions
impressed upon the face by the contraction of this or that muscle has,
from the researches of Duchenne (of Boulogne), become a study which
presents all the precision and certainty that we can claim from facts
strictly deduced from anatomy.
Before the researches of Duchenne, the majority of books written on
expression dealt almost entirely with _physiognomy_, or the means of
recognising the character by the study of the habitual state of the
traits of the countenance. We shall, in the first place, mention the
works of Le Brun, Camper, Lavater, C. Bell, Humbert de Superville, and
Sue, and then we shall refer to the investigations of Duchenne and
Darwin.
Long ago, in the drawings of Leonardo da Vinci, we find some valuable
indications of the state of the face and neck in the expression of
the emotions. This great master, for example, clearly perceived the
part that the platysma muscle of the neck takes in the expression
of violent passions, and portrayed the transverse folds which then
mark it beneath the chin. Le Brun, however, was the first to arrange
studies of this character into a doctrinal series. The publications in
which his views on this subject have been preserved are numerous.[7]
The artist will find there a number of interesting observations,
curious comparisons, and ingenious explanations. Le Brun occupied
himself principally with the resemblance of certain types of human
physiognomies to the heads of animals; in short, he studied physiognomy
in relation to character.
Camper, whose works we have already quoted respecting the facial angle
(page 181), was an anatomist and an artist. He analysed the action of
the facial muscles, and it was he who first laid down this general
rule--viz. that the contraction of each muscle of the face produced in
the skin one or more folds, of which the direction is always at right
angles to that of the muscle, a precept that we shall find to be true
with regard to almost every muscle of the face, and especially for the
frontalis, the great zygomatic, &c. Besides the exact observations that
the artist will meet in the works of Camper, he will find in addition
an interesting historical account of the question.
An English anatomist, Sir Charles Bell, celebrated for his studies
of the nervous system, also analysed the expressions of the face.[8]
But though his work affords picturesque descriptions and admirable
illustrations, it is more interesting to the anatomist than the artist.
The title of the work of Lavater (_The Art of Knowing Man by his
Countenance_)[9] indicates the object sought by the author. We find
in this work good illustrations, and curious observations especially
applicable to the study of physiognomy, but frequently without order,
without method, and accompanied by dissertations on whimsical subjects,
such as the chapters devoted to _imaginations_ and _envies_, to _warts_
and _beards_, and to _lines of animality_, &c.
In order to have an idea of the manner in which, at this epoch, authors
attempted the study of physiognomy, making this delicate analysis a
pure affair of sentiment, it is sufficient to mention the work of Sue
(_Physionomie des Corps Vivants, considéré depuis l’Homme jusqu’à la
Plante._ Paris, 1797.) In the middle of a long affected treatise on
physiognomy and its relation to the passions, this, for example, is
how he expresses himself concerning the mouth:--“A mouth delicate and
pure is perhaps one of the best recommendations. The beauty of the
portal proclaims the dignity of that which passes through. Here also
is the voice, the interpreter of the heart and mind, the expression
of truth, friendship, and the most tender sentiments.” With regard to
the incessant comparison of human physiognomy with that of animals,
the author stops at nothing in this singular course, and speaks
dogmatically on the physiognomy of fishes, serpents, grasshoppers, and
intestinal worms (!), as well as that of man. “Many fishes,” said he,
“are wanting in that which gives a character of amenity, kindness, and
tenderness.” “The intestinal worms have a very decided physiognomy ...
the character of their physiognomy inspires in man sorrow and awe.”
Amidst the works of a more serious, though still empirical character,
we must mention in particular one which, although dealing with the
countenance only in a secondary degree, yet presents several valuable
observations on this subject. We have endeavoured to utilise these
investigations in the diagrammatic representation of the action of the
muscles of the face. We speak of the treatise of Humbert de Superville
(_Des Signes Inconscients de l’Art_, 1827). The author gives three
drawings of the human face, in which the lines represent the eyes, the
lower boundary of the nose, and the lips. In one of these drawings
(Fig. 90) the lines are all horizontal, in the second (Fig. 91) they
are all inclined downwards and outwards (from the median line), and
in the third (Fig. 92) they are all inclined upwards and outwards.
The author remarks that the first figure (with the lines horizontal)
produces an impression of calmness, greatness, and constancy; and
he adds that in the same way in nature and architecture horizontal
lines give rise to the idea of calmness, stability, and grandeur: the
cedar, with its horizontal branches, is of all the trees the one that
realises this impression in the highest degree. On the contrary, the
second figure (with the lines directed obliquely downwards) gives
an impression of sadness, pain, and grief; and the author does not
fail to compare the direction of the features of such a countenance
with the direction of the architectural lines in tombs and funeral
monuments, and that of the branches of the trees which everywhere are
planted in preference to others in cemeteries, and whose branches
always hang obliquely. Lastly, the third figure (with the lines
obliquely upwards) gives rise to the impression of gaiety, laughter,
levity, inconstancy; and, to continue the preceding comparison,
everyone must acknowledge that Chinese architecture, with its lines
oblique and diverging upwards and outwards, can never--at least, in the
eyes of a European--produce an impression of grandeur and majesty.
[Illustration:
FIG. 90. FIG. 91. FIG. 92.
THE THREE FIGURES OF HUMBERT DE SUPERVILLE--(Fig. 90, calmness;
Fig. 91, sadness; Fig. 92, gaiety).]
These figures, and the remarks that de Superville makes afterwards,
but which we have not emphasised here, are strikingly exact, when
we consider the features in the state of movement or in a momentary
expression of emotion. All the muscles which take part in the
expression of pain, sadness, and contempt help to incline the features
obliquely downwards and outwards, some by acting on the outline of the
eyes, others on that of the mouth, &c. On the contrary, the muscles
of laughter, raising its angles, draw the mouth obliquely upwards
and outwards, and--for certain reasons that we will analyse further
on--seems to give a similar direction to the outline of the eyes. In
a word, features, starting from the state of repose, represented by
the first figure of Humbert de Superville (Fig. 90), oscillate in two
opposite directions, either ascending, to express the scale of gaiety
and laughter (in which the features are oblique upwards and outwards,
Fig. 92), or descending--sadness, pain, and tears (in which the
features are oblique downwards and outwards, Fig. 91). The exactness
of the drawings furnished by Humbert de Superville for the general
expression of the physiognomy induces us to try, by similar drawings,
to represent the action of each muscle separately. Knowing the action
of a muscle, and knowing from the photographs of Duchenne the direction
that it imparts to a certain feature of the face, either to the line of
the eyebrows, the opening of the eyelids, the nostrils, or the lips,
we have indicated by a simple stroke or line these changes, either
in direction or in the form of one of those lines, and have obtained
theoretical figures sufficiently expressive to characterise the emotion
geometrically, so to speak, in the manifestation of which this or that
muscle is affected. Such are the Figures 96, 98, 100, 102, 103, 104,
106 (page 317 and following), by means of which we will attempt to
explain the action of each muscle of expression. We may say that these
drawings, without any pretension, are, so to speak, the primer of the
language of physiognomy.
We now arrive at the history of the work of Duchenne, to which we
owe all that follows. While all his predecessors had been taken up
with observation, Duchenne introduced the experimental method into
the study of physiognomy. His process, simple in conception, was very
delicate in application. His method was to cause the contraction of
each muscle _singly_, and that the expression that resulted might be
appreciated not only at the moment of the experiment, but again at any
time, and submitted to the judgment of all, he photographed the subject
at the moment when the muscle was contracted. This last operation was
easily accomplished, but the excitation of a single muscle was a more
delicate operation. Everyone knows that by electricity, in placing
the two electric needles (the two poles of the current) on the course
of a muscle, we can cause the contraction of the muscle beneath the
skin. But no subject would lend himself to this experiment. At first
he tried on the dead body of an executed criminal a short time after
death; but the muscles of the face lose their excitability two hours
after death, and then it is only by actual exposure of the muscle and
direct stimulation that we can obtain contraction by the application of
electricity. On the other hand, if we attempt it on any living subject,
we can, it is true, cause a muscle to contract by applying electricity
over its site; but the electric current, traversing the skin to reach
the muscle, at the same time that it excites the motor nerves of the
muscle, excites also the sensory nerves of the skin and produces acute
pain. From this fact we see that we produce on the face of the subject,
not a simple and characteristic expression, but a true grimace, or an
irregular contraction of all the muscles under the influence of the
pain.
Duchenne had the good fortune to be able to experiment on a subject in
whom a particular infirmity rendered impossible the last inconvenience
we have noted. This was an old pensioner of the hospital who had
_anæsthesia_ of the face (ἀνα, absence of; αἴσθησις, sensibility),
in whom the skin of the countenance was insensible to the most painful
excitation; electricity could be applied to the skin without producing
any painful reaction, and yet excited the muscles beneath, which had
perfectly preserved their contractility, and performed their functions
as in a normal subject. He could, therefore, cause this or that muscle
to contract alone, and could excite, for example, the action of the
great zygomatic, giving to the face the expression of laughter,
without the subject having any idea of what his physiognomy reflected;
his face, by the action of the electricity, was laughing, while his
thoughts might be indifferent or fixed on sad recollections; on the
other hand, for example, by the contraction of the superciliary muscle,
his countenance might express the most acute pain, while his thoughts
might be quite indifferent or borne away by gay and pleasant ideas. In
a word, Duchenne was able to realise, under the most precise conditions
of experiment, an exact study of the uses of the muscles of expression.
The work in which Duchenne has given the result of his labours is
remarkable particularly for the magnificent atlas of photographs that
accompany it, and which have been obtained by the above process. From
these photographs have been reproduced as exactly as possible the
several figures that accompany the descriptions which follow (Figs.
95, 97, 99, 101, page 316 and following). We cannot enter here into
a complete statement of the results obtained by Duchenne, but we
will seek at least to show the serious and scientific value of these
studies, and to inspire the student to refer to the original work.
These studies have for the artist this important result--namely, to
prove to him that frequently the contraction of a single muscle is
sufficient to express an emotion, and that it is not necessary to
change all the features in order to give to the face the stamp of pain,
attention, menace, contempt, disgust, &c., each of these sentiments
being expressed by a slight modification, either of the eye alone, or
of the lip alone. Each expression has, so to speak, its own exact,
precise, and separate mark, produced by a single local modification;
but this local modification seems to be reflected throughout the
physiognomy, and therefore, from unaided observation, artists had for
a long time believed that, for example, attention and pain were shown
by the combined action of a number of facial muscles. Now experiment
proves that pain may be expressed solely by a muscle which raises and
wrinkles the brows, and on a face (Fig. 99) where this muscle alone is
contracted (_superciliary muscle_, page 320) the expression of pain is
complete. We naturally believe that the mouth also takes part in it,
but if we cover the upper part of the countenance, we perceive that the
lower part of the face is in a state of complete repose.
To bring to a close this history, which is not the least interesting
part of the subject, we must say that the labours of Duchenne were not
at first received with great favour in France. Physiologists as well
as artists showed a certain distrust of a work which pretended to give
precise rules and scientific laws to a subject about which it had been
the custom to make fanciful and sentimental comparisons. Few persons
understood the nature of the reason which forced Duchenne to choose as
a subject for these experiments a poor man with a physiognomy almost
imbecile in repose, and they did not consider that if this face was
old, wrinkled, thin, and vulgar, there was the greater reason to be
struck with the precision with which the electric excitation enabled
the most opposite and characteristic expressions to be taken.
As has been too often the fate of scientific discoveries, the work of
Duchenne was neglected in France, and was not appreciated until it had
been adopted by a foreign country. It was Darwin who made the results
of the French physiologist the basis of his own interesting studies.
It is not necessary to recall the extent and repute of the works of
Darwin on _The Origin of Species_, on the _Evolution of Animals and
Plants_, and on _The Descent of Man_. What this great naturalist has
done for the general morphology of plants and animals he sought to
do for the subject of physiognomy. Seeking in the logical chain of
natural facts the cause of all biological phenomena, he endeavoured to
discover by the attentive study of the movements of expression, and
through their origin and development, a series of new arguments in
favour of the theory of evolution. In a word, Darwin, by invoking the
association of certain useful movements, and comparing the functions
with the expressions with which they are associated, sought to explain
why one muscle in particular rather than another is affected by the
expression of this or that emotion. We cannot here enter further
into the analysis of this philosophical work. It is sufficient to
remark (having commended the perusal of it as most interesting to the
artist[10]) that before we explain anything it is necessary that it
should be firmly established. Therefore the explanation of the part
that each muscle takes in the expression must be impossible until the
fact of the action and the expression associated with the movement of
the muscle has been scientifically demonstrated. The philosophical work
of Darwin could not have been undertaken if it had not been preceded by
the experimental work of Duchenne.
Summarising Darwin’s argument, his thesis may be stated somewhat as
follows: that every expression or bodily manifestation of emotion has
a physical basis, and an origin in some _useful exercise_ of the
particular muscles concerned; that such an action becomes habitual
in the individual, and is transmitted from father to son, and from
generation to generation; and that the actual physical cause is
transferred to a mental condition, so that an action like knitting the
brows--primitively for the purpose of actually clearer vision--becomes
indicative of a mental state in which the emotion is expressed of a
desire for a clearer mental vision, as when a man is engaged in any
intellectual problem.
Darwin further enunciated the important principle of _Antithesis_:
which means the employment of exactly the opposite expression (it may
be by the relaxation of muscles, or by the contraction of antagonistic
muscles), to indicate an opposite or antagonistic attitude of mind.
Thus joy is expressed by the contraction of a definite series of facial
muscles; grief or dejection is expressed by the relaxation of these and
the contraction of opposing muscles. The healthy, alert man holds his
head erect; the depressed or miserable has a drooping gait.
A third principle enunciated by Darwin as employed in producing the
expression of emotion is _the direct action of the nervous system_, to
a large extent independent of the will, and served mainly through the
sympathetic nervous system, such as blushing, trembling, perspiration,
&c.
It is important, as Darwin points out, to bear in mind that emotion is
expressed not only by facial expression, but by many other agencies as
well; by the emission of sounds, by the voice in some cases, by the
rattling of the tail quills in the case of the porcupine, &c.; by the
inflation of the body, as in the hen who raises up all her feathers
in maternal anger, or the dog whose hair stands on end; by gestures,
rubbing, licking, caresses, kisses; or by the attitude and movements of
the body, head, or limbs.
In his book each emotion and its corresponding expression is carefully
analysed, and the physical cause and the particular muscles engaged
are pointed out. Thus Darwin says, “Weeping is the result of some such
chain as follows: Children wanting food or suffering in any way, cry
out loudly as a call to their parents for aid, like the young of most
animals. Prolonged screaming leads to the gorging of the blood vessels
of the eyes; and this causes first consciously and then habitually the
contraction of the muscles round the eyes in order to protect them.”
The mouth at the same time is opened widely to allow of a more vigorous
scream. The overflow of tears is a consequence of the closure of the
eyes.
Again, in regard to the facial expression in laughter, Darwin suggests
that as the primitive cause of laughter may have been a practical
joke--or, as De Rochefoucauld put it, there is something pleasing in
the misfortunes of one’s friends--the expression may be associated with
the retraction of the angles of the mouth, and the exposure of the
canine teeth, in preparation for self-defence if the victim of the joke
should retaliate.
The expression of disdain or disgust in the same way is associated with
the contraction of muscles of the eye, nose, and mouth, primitively
from purely physical causes, which have become connected with a mental
attitude. The head is turned aside, and the eye is half closed to shut
out an unpleasant sight; the nostril is raised at the sensation of a
disagreeable smell, and the lips are curled in disgust at a nasty taste.
There is not space in which to dwell further on these deeply
interesting questions, for a study of which the reader is referred to
Darwin’s masterly treatise on the subject.
The figures which illustrate the work of Darwin are in a great measure
only reproductions of the photographs published by Duchenne about ten
years previously. However, as we have already mentioned, attention has
been recalled in France to the works of Duchenne, a more favourable
judgment has been passed, and justice has been rendered to him who
had opened the way to the experimental study of physiognomy. In 1874
the French began to devote, in the course of anatomy in the School of
Fine Arts, several lectures to the account of what we must call the
primer or grammar of the expression of physiognomy. Happy in seeing
his works included in this classical course of instruction, Duchenne,
whom death carried off a few years later, gave to the School of Fine
Arts the complete series of large original photographs from which these
publications are reduced, and this beautiful collection is to-day one
of the most valuable in the French museum of anatomy (Muséum Hugnier).
Although this account may appear long, it is nevertheless very
incomplete, being given only with a particular object--that of
comparing the works of Duchenne with those preceding him. Those of
Duchenne will be made the basis of the studies which follow. We will
finish by noting, as interesting and instructive, the works that treat
in a more general manner of expression and physiognomy, such as those
of Lemoine, Gratiolet, and Piderit.[11]