Page:Popular Science Monthly Volume 37.djvu/531

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515
CENTERS OF IDEATION IN THE BRAIN.

Let me give an example. The outward sign of a joyful emotion is a drawing up of the corners of the mouth. The elevation of the angles of the mouth is the muscular action going parallel with the emotion of joy. The excitation of the nerve-center causes the elevators to act. There is but one definite area from which the elevator muscles can be made to act, therefore joyful emotions must take their start from this center. When, then, a joyful emotion excites this definite portion of gray matter, a nerve-current passes to the lower center—the center for the movements of the elevator muscles—and causes them to act. As the brain is a very complex machine, other effects may be produced at the same time, but this one has always been associated particularly with exhilarating emotions. Persons of very cheerful dispositions make the elevators act so frequently that the mechanism of the nerve-display is facilitated by constant use, and the center will easier appreciate these special impressions. The elevators will be in time so accustomed to act that they will leave impressions on the face so marked to enable people to recognize, by mere physiognomical signs, their brethren who are of such disposition.

Now, let us see what the actual experiments were.

PSM V37 D531 Centers of the muscular movements of the arm.jpg
Fig. 1—Diagram. (David Ferrier.
(7) Center for movements of the elevator muscles.
(15) Gustatory center.
(11) Center for movements of the "platysma myoldes muscle."
(5) Center for movement of the arm and raising of the shoulder. (Patience muscles.)

Prof. Ferrier applied a galvanic current to the ascending frontal convolution in monkeys on a definite portion, marked 7 (Fig. 1), and to the corresponding region in dogs, jackals, and cats, all with the effect of elevating the cheeks and angles of the mouth with Closure Of the eyes. On no other region could the same be effected.

Darwin (Expression of the Emotions, p. 202, etc.) says "Dr. Duchenne repeatedly insists that under the emotion of joy the mouth is acted on exclusively by the great zygomatic muscles, which serve to draw the corners backward and upward. The upper and lower orbicular muscles are at the same time more or less contracted. A man in high spirits, though he may not actually smile, commonly exhibits some tendency to the retraction of the corners of his mouth. According to Sir Charles Bell, in all the exhilarating emotions the eyebrows, eyelids, the nostrils, and the angles of the mouth are raised. The tendency in the zygomatic