Page:Popular Science Monthly Volume 85.djvu/576

572 defect. The normal range of about 2:1 in such processes is thus indefinitely extended.

In other mental diseases these questions scarcely apply. Thus we do not speak of a characteristic psychomotor retardation or acceleration in general paralysis, arteriosclerosis, or dementia præcox. Only in the case of immediate drug intoxication has a stimulating effect been attributed to such poisons as alcohol, morphine and cocaine. Experimentally, the effect of alcohol seems to be to remove inhibitions, so that there is greater freedom of motor response. Many premature and false reactions occur. Morphine and cocaine are too dangerous for experiment, though both may be taken with the idea of temporarily stimulating the mental powers. The former does appear to bring about a certain facilitation of the thought processes, its effects being in some ways opposite to those of alcohol.

The range of normal variation is so great that few abnormalities in the association experiment can be attributed to pathological conditions except with knowledge of the subject's normal reaction. The rather stable character of the association type through normal life makes its fluctuations through the psychoses of considerable significance; but the individual differences there are of very doubtful interpretation. It is scarcely evident that there are features of themselves characteristic for different psychoses except in dementia præcox, where irrelevancies, neologisms and stereotypies are frequent in the presence of good appreciation of the experiment. "Narrowing of mental horizon," according to Kent and Rosanoff, is prominent in grave neural disorders such as epilepsy or general paralysis. Nothing approaching specific alterations has been observed in other psychoses. It is certain that normal performance is not incompatible with severe manic-depressive states; and the marked tendency to unusual associations—the prime feature of the psychoses in general—occurs also in personalities that are distinctly better than the normal average.

There is no clinical entity among the psychoses in which memory is improved, though the hysterical hyperamnesias furnish particular instances of it, as the corresponding amnesias do of memory gaps. Memory defect is a special characteristic of mental disease accompanying the coarser brain lesions, as general paralysis, arteriosclerosis, or senile dementia. It is most prominent in the last named, and also more especially associated with recent experiences. The loss in general paralysis is rather generalized over the entire memory field, and in arteriosclerosis it tends to be "patchy," so to speak, losing and retaining here and there, though not with systematic amnesia in the hysterical sense. The most prodigious memory defects are seen in a psychosis of usually alcoholic origin, the Korsakoff syndrome, where, in spite of good understanding, all impressions are immediately lost; indefinite