GUSTATORY IMAGINATION AND MEMORY
_The Nature and Frequency of Mental Images_
IT is a familiar fact that in one way or another and in different
degrees to different individuals it is possible to have sensory
experiences without the actual presence of their accustomed stimuli.
Thus, many people can recall “in their mind’s eye” the colors of
objects, their shape and structure, when they are no longer in the
presence of the object thought of. Or, “in their mind’s ear,” they can
hear the blare of a trumpet, the voice of a friend, the hissing of
steam, when no corresponding stimulus is present to the ear. Similarly,
“in imagination” many can experience the tactual feel of velvet, the
odor of onions, the warmth of sunshine, the ache of a tooth, the nausea
of seasickness.
“Thus, I can call up in my mind’s eye, more or less vividly, my boyhood
home, and seem to see, though more obscurely than if I were present on
the spot, the house and barn, the grape arbor, the garden, even my
little bookcase in the library. I can smell the honey in the bee boxes,
and can hear the general hum and stir of the hive. I can do this because
I can call up images of these past experiences. Or, by putting together
the images of wheels, sails, birds, and ropes which I have actually seen
I can create in my mind’s eye an aeroplane of a pattern which has never
yet been constructed.” This constructive performance would constitute
“imagination” as distinguished from mere “imagery.”
These images of imagination are not to be confused with the after
sensations which we have already described. They may be experienced
days, or even years, after the first application of the original
stimulus. Nevertheless, these “mental images,” or “centrally excited
sensations,” are described as essentially sensory in character—they have
the attributes of all sensory experiences, such as intensity, extensity,
duration, clearness, locality, quality, and modality. In fact observers
have been found for whom these mental images were so realistically
sensory that actual negative after sensations, in the case of visual
images, have been reported as following upon them.
In the case of many individuals, these experiences of objects in their
absence are relatively rare and obscure, and in some cases, indeed, are
so obscure as to lead the individual to deny the existence of such
experiences. In still other cases the centrally excited sensations, the
mental images, are experienced in their vivid and, apparently,
immediately sensory form only under special conditions, as in dreams,
hallucinations, drowsiness, or fatigue, or under the influence of
special drugs. It has appeared from the study of mental images that, in
so far as they are present, they are not equally reported in the
different modes of sensation. Visual images in some cases, auditory
images in other cases, and motor images in still others, have seemed to
be so specially frequent, vivid, or easily aroused that at one time it
was customary to classify individuals on the basis of their images as
visuelles, audiles, motiles, and efforts have even been made to adapt a
method of teaching to the presumed “imagery type” of the student. In the
present connection our interest is only in inquiring whether and in what
degree “images of taste” are present.
_Mental Images of Taste_
Is there a “gustatory” or taste imagination as well as a visual or an
auditory imagination? It should, of course, be borne in mind that tastes
may be “thought of,” “referred to,” or “indicated” without there
actually being taste qualities present in experience. Thus, I may refer
to the “saltiness of the pork” and discuss it in detail without having
in consciousness the sensory tang and quality of “salt.” The saltiness
may be “represented” in my thinking in this case, not by a taste quality
at all, but by the word which stands for such a quality, or even by a
visual picture of a white granular substance, or an elongated strip of
meat. Only if the immediate and unanalyzable experience of sensory
“salt” is present is there evidence, in this case, of an “image of
taste.”
Obviously, we must mainly rely in such cases on the testimony of the
observer, although there have been investigations made of a more
objective sort, in which it is shown that the reported “images” are so
similar in character to actual sense experiences that the observer,
under appropriate conditions, cannot distinguish between the two.
If we turn to the results of introspection or individual testimony, we
find that if taste images exist at all they are at least reported as
very much less frequent and vivid than are images from other senses.
Thus, one observer, who in the course of two years’ observation of his
own experience recorded 2,500 “images,” classified these as follows:
Vision 57%
Hearing 20%
Smell 6%
Taste 6%
Touch 4%
Movement 3%
Temperature 2%
Organic 1%
Emotional 1%
Much the same state of affairs is revealed if one attempts, when certain
objects are named, to record the imagery which the name evokes. In
response to the word “tornado” some individuals at once report visual
appearances of falling houses and waving trees, while others report
auditory experiences of crashing buildings and rushing wind. Within a
few moments most observers report the appearance of images from various
senses, though some of them are more vivid, more prompt, or more
enduring than others. In the case of taste, however, it is rare that
images are reported as either vivid, prompt, or lasting. Usually when
such an image is reported at all it is described as lagging behind the
images of other modes, appearing to be dragged in or reënforced by them,
and to be transient, weak, and fluctuating. It seems, also, that,
although images of taste are not easily aroused directly by words, their
appearance is facilitated if a visual image or impression is present
with them. Consequently, when the poet or the advertising writer desires
to provoke imagined tastes in his readers he often attempts to arouse
them more effectively by presenting suggestive pictures of scenes
associated with the object, or a tempting array of the articles
themselves in an agreeable setting.
_Taste in Dreams and in Hallucinations_
Reports of the sensory components of dream experiences show taste to be
an inconspicuous factor in dream life. The following table shows the
results obtained by two independent investigators when dreams of various
individuals were analyzed into the sensory elements reported:
Percentage of
Occurrences
Sensory 381 300
Mode Dreams Dreams
Vision 84.5% 67%
Hearing 67.7% 26%
Touch 10.8% 8%
Smell 6.9% 1%
Taste 6.3% 1%
Records of the hallucinations of sane and insane people also show taste
to play a relatively minor rôle, so far, at least, as frequency of
report is concerned. In both cases visual, auditory, tactile, and
olfactory hallucinations seem to be more common experiences. “Subjective
tastes,” or tastes which do not appear to be caused by the action of any
substance in the mouth, are, however, by no means unknown, although in
most cases it is apparent that these tastes come from some unsuspected
irritation of the taste organs by actual agents. Substances circulating
in the blood may often be seen to be responsible for these “subjective
tastes.” Thus, in diabetes the excess of sugar in the blood may give
rise to a persistent sweet taste, and in case of jaundice biliary
products often produce sensations of bitter. Various drugs, when present
in the blood stream, also provoke well-known effects in taste, and it is
quite probable that the taste hallucinations associated with nervous and
mental disorder have their origin in some abnormal irritation of the
nerves or brain centers involved in taste. Distilled water, which is
presumably as tasteless a substance as could be found, is reported as
tasteless by only about 50 per cent of observers. About 25 per cent
report it as having a bitter taste, while certain cases are found in
which it tastes sweet, or salt, or sour, or as having some unknown
taste. As the result of careful study of these facts, Brown suggests
that “we may perhaps infer that the ‘taste’ of water is not, after all,
a taste quality, but is due rather to the presence or absence of some
tactual characteristic; the absence, perhaps, of the ‘bite’ which is
associated with sweet, salt, and sour alike.” It is also possible that
mechanical stimulation of the taste organs can produce true taste
qualities, just as mechanical stimulation of the retina produces spots
of light and the tapping of a “warm spot” may produce a faint sensation
of warmth.
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