of any other word in
terms of either visual or auditory or motor imagery. In all
probability the auditory and motor always occur together,[6] but
still it is possible to make the one or the other predominate.

It appears that the imagery of most persons is a mixture of
auditory-motor and visual elements, with a predominance of one or
the other kind. Individuals who utilize almost exclusively the
visual (as does the author, as a rule), are rare. But rarer still is
the pronounced motor type.]

While I was still ignorant of the nature of the necessary movements, the
tests were successful only when I had put the question aloud or in a
whisper, but never when I failed to enunciate, i. e., when I merely had
the question in mind ("in idea"). But this also became possible after a
little practice, although I could not then give an explanation for my
success. Except in one instance, we could discern no difference between
problems spoken and those merely conceived by Mr. von Osten who had had
the advantage of long practice. But the one exception deserves mention.
The old gentleman commissioned Hans, presumably without uttering a word,
to step backward to the left. Hans thereupon responded by giving his
entire repertoire, as follows: He moved his head to the right, then to
the left. Then he leaped forward and repeated the same movement of the
head. Hereupon he stepped backward and signified a "yes" by a movement
of the head. He then lowered his head and made two leaps forward. After
this performance Mr. von Osten repeated the same command aloud, and in
every case Hans responded properly. Again the silent command was given
and again the horse responded with the series of reactions described
above, lowering his head leaping forward, etc. In this experiment,
without exception, the spoken command evoked adequate reactions,--the
silent command, an incorrect response. Evidently the impulse to movement
was not so great with the mere conceiving of "right", "left", etc., as
when the words were enunciated. It, therefore, required some practice on
my part before a sufficiently strong movement-impulse became associated
with the idea. All this is in no wise at variance with the fact that
tests involving counting and computation were as successful when the
problem was given in silence, as when it was spoken. The signs for
tapping, viz.: inclination and erection of the head and body, followed
the question. The qu