A very definite answer to this question is furnished
by observation of the behavior of the dancers in the
tests. Most of them continuously made use of
their eyes, their noses, and their vibrissae.
Some individuals used one form of receptive organ
almost exclusively. I frequently noticed that
those individuals which touched and smelled of the
labyrinth passages most carefully gave least evidence
of the use of sight. It is safe to say, then,
that under ordinary conditions habit formation in the
dancer is conditioned by the use of sight, touch,
and smell, but that these senses are of extremely
different degrees of importance in different individuals.
And further, that, although in the case of some individuals
the loss of sight would not noticeably delay habit
formation, in the case of others it would seriously
interfere with the process. When deprived of one
sense, the dancer depends upon its remaining channels
of communication with environment. Indeed there
are many reasons for inferring that if deprived of
sight, touch, and smell it would still be able to learn
a labyrinth path; and there are reasonable grounds
for the belief that a habit once formed can be executed
in the absence of all special sense data. Apparently
the various receptive organs of the body furnish the
dancer with impressions which serve as guides to action
and facilitate habit formation, although they are
not necessary for habit performance.
The reader may wonder why I have not carried out systematic
experiments to determine accurately and quantitatively
the part which each sense plays in the formation of
a labyrinth habit instead of basing my inferences upon
incidental observation of the behavior of the dancers.
The reason is simply this: the number and variety
of experiments which were suggested by the several
directions in which this investigation developed rendered
the performance of all of them impossible. I
have chosen to devote my time to other lines of experimentation
because a very thorough study of the conditions of
habit formation has recently been made by Doctor Watson.[1]
What is the role of sight in the dancing mouse?
How shall we answer the question? The evidence
which has been obtained in the course of my study
of the animal indicates that brightness vision is fairly
acute, that color vision is poor, that although form
is not clearly perceived, movement is readily perceived.
My observations under natural conditions justify the
conclusion that sight is not of very great importance
in the daily life of the dancer, and my observations
under experimental conditions strongly suggest the
further conclusion that movement and changes in brightness
are the only visual conditions which to any considerable
extent control the activity of the animal.
CHAPTER XII
Copyrights
The Dancing Mouse from Project Gutenberg. Public domain.
