Motor tics, such as habitual jerking of the arms, shrugging the shoulder, contorting the face, shaking or nodding the head, snapping the fingers, etc., are very common among nervous children, and even in many otherwise normal grown-ups.
Distractibility is an abnormal variation of attention.
The common inability of the hypomanic patient to hold his attention to any subject when another is open, is very like the distractibility of the child who turns to every new interest as it is presented.
Negativism is a state of persistent compulsion to contrary response to suggestion.
It is with these patients as though not only initiative were lost but also the power to follow another’s lead. But their independence asserts itself in opposing every suggestion and in acting so far as possible contrary to it.
Mutism, as used in psychiatry, is an abnormal inhibition to speech.
Patients sometimes speak no word in many months. To all appearance they are true mutes. Then suddenly something may remove the mental blockade and they talk.
Compulsive acts are acts contrary to reason, which the will cannot prevent.
A seemingly quite normal patient will sometimes grab a vase from a stand in passing, and dash it to the floor. Something “urged” him to do it, and he could not resist. Others will tear their clothes to shreds, not in anger, but because they “could not help it.”
Psychomotor overactivity is abnormal activity of both mind and body, contrary to reason and uncontrolled by will.