In passing I may say that the tic movements may have a special, individual, psychological significance. But this is by no means necessarily so. Frequently, I am inclined to believe usually, these movements result rather merely because there has been effected a psychobiological reaction, following the theory of psychophysical-progression, fixation and regression with involvement of the nervous paths most seriously affected or most easily disturbed.
In the case of the tics, therefore, it is as if the various tic movements are being used in reaction to or in adaptation to sources of internal or external, physical or mental irritation, for the protection, defense or self-preservation of this or that particular part of the nervous system—as if the movements which we find in the tics and which are the expressions of certain engrams, neurograms, mnemes or organic memories, are existing in and for themselves, except that, in the tics, they are reacting with and for the psychophysical organism, the organic make-up or personality.
The individual, as a biological unit, is reacting to the particular situation which presents itself by the tic mechanism.
By granting the phylogenetic, racial significance we also give the basic, psychophysical meaning of tics in all ticquers.
EXCITING FACTORS
How is it that these activities may come into play again? What brings them to the surface once more?
There are many factors which come in for consideration in this connection. In the first place the basic cause is the instinctive, organic, psychophysical make-up of the individual. Whether and which functions re-exist as of old and respond as means of adaptation and self-preservation, depends on the stability and the weaknesses or defects of the nervous mechanism or system with its various parts, systems, functions or inherent psychophysical dispositions on the one hand, and the life-experiences and the immediate inciting factor on the other hand.
A neuropathic or psychopathic or neuropsychopathic constitution with its usual causes (germinal, intrauterine or extrauterine, usually of a toxic, infectious or disturbed metabolic nature, and including particularly alcohol, syphilis and nutritional disorders) may form the ground work. This predisposition may be congenital—that is, present from the date of birth, although not necessarily germinal in origin, or it may be acquired at some period in life from physical or psychic causes. In this connection the infantile and early childhood history are very important. Consequently the diseases, training, example, education and opportunities in childhood and infancy are of very great significance, the parental training and example and the home conditions having a most intimate relationship to the development of many of these tics. Imitation and mimicry here play a decided role. Spoiled children, too quickly satisfied or over repressed, are apt to develop tics. External somatic irritations may be the starting point in some (not in all) cases. At other times an idea (normal or abnormal) may incite the tic movements. Auto and hetero-suggestion, hypochondriacal ideas, hysterical symptoms and obsessions may, particularly in adults, initiate tics. Obsessions are especially apt to produce habits or tics, if they produce any motor reaction. Tics may develop into obsessions and vice versa; or both may co-exist simultaneously and be unrelated. The original ideas which led to the movements vanish while the movements survive. In the insane various sorts of delusions may be the groundwork on which a tic may later develop. Habit movements, which represent purposive physiological acts which have become automatic and not inhibited (hence showing weak will power) and which seek strongly for expression, which the individual struggles against and endeavors consciously to inhibit and overcome after the tendency is fairly well developed, may eventually become impulsive and irresistible with the ultimate evolution of the psychic state which is characteristic of ticquers. Automatic habits and mannerisms or stereotyped acts are of course not tics but the latter are but caricatures of the former with an added characteristic mental state. Tics, as mentioned earlier in this paper, are thus pathological habits.
Tics may also be but the symbol for a vague feeling of tension, irritation or stimulation, which seeks relief or expression by the performance of the tic.
Emotional stress and strain, fright, fear, excitement and mental shock can arouse a tic. Mental conflict and unrest has not received that degree of attention which it surely deserves. Clark and the Freudian school have definitely called our attention to this aspect. Bresler refers to tic as a motor reaction to original mental shock, so that it is in fact a psychic defense reaction of expression. Dupre has stated that emotional shock may act as a possible exciting cause of tics, as at times of obsessions. Meige and Feindel have asserted that fear may excite a movement of defense, and although the exciting cause has vanished, this movement may continue to persist as a tic. They also mention that in ticquers we frequently find the impulse to seek a sensation and to repeat to excess a functional act.