disease, or is threatened with tuberculosis--all in his mind; and
whatever the disorder he seizes upon, his attention hovers there, while
the ideas of that particular disability persist and strengthen.

A _flight of ideas_ is an abnormal rapidity of the _stream of thought_.

Every perception so immediately is linked with some association of
experience that expression is swift and often incoherent. One word will
follow another with amazing rapidity, words suggested by sound
association, usually, rather than by that of meaning.

Example: "Made a rhyme, had a dime, did a crime, got the time, bring
some lime." This association by rhyme is quite common. But the
associations of meaning are not uncommon.

Example: "Made a rhyme. Mary was a poet. Mary had a little lamb. Where's
Mary?--Mary!--No Jim--Jim, all my children--calling, calling, calling,"
etc.

A _fixed idea_ is one which morbidly stays in the mind and cannot be
changed by reason.

Example: In hypochondriasis, as given above.

_Ideogenous pains_ are either pains born of an erroneous idea, or mental
reproductions of pains now having no physical cause.

A suggestible person, learning that his grandfather died of an organic
heart, conceives the idea that he has inherited the trouble, and begins
to suffer cardiac pains; and as long as the idea persists the pain is
felt.

_Compulsive ideas_ are ideas which intrude, recur, and persist despite
reason and will.

Example: The compulsive idea of contamination may lead its victim to
wash and rewash his hands at every contact with matter, until finally,
though they are raw and sore, he is incapable of resisting the act.

_Disorientation_ is a state of mental confusion as to time, place, or
identity.

_Amnesia_ is pathologic forgetfulness.

Example: As sometimes found in the infection-exhaustion psychoses, when
the entire past of the patient may be wiped out for the time. Cases of
permanent amnesia are known.

_Aphasia_ is a defect in the interpretation or production of language.

There may be motor aphasia, auditory aphasia, vocal aphasia, sight
aphasia; and with disability to produce words, they may yet be
recognized when seen; or when they can be spoken they may not be
recognized when heard; or with inability to speak them, they are
accurately sensed by hearing; or though understood when heard, they are
incomprehensible when read.

A _delusion_ is a false belief which cannot be corrected by reason.

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