UNUSUAL AND ABNORMAL TASTE EXPERIENCES
_Gustatory Hallucinations and Auræ_
DISORDERS of taste are for the most part neither as varied nor as
bizarre as the abnormal conditions of the more complex senses. Illusions
of taste, hallucinations, and subjective tastes we have already referred
to as frequently found. But of them little can be said, except that they
occur, and that they present very little of psychological interest. The
appearance of these subjective tastes may in some cases be due merely to
the fact that “a taste sensation easily associates itself with certain
muscular sensations. Thus, pressure on the base of the tongue provokes
the movements of vomiting. With this muscular sensation may be
associated a sensation of bitter, which accompanies violent nausea.” In
ways similar to this some observers would explain the reports of others
who find taste sensations to be produced by mechanical stimulation of
papillæ. Most observers do not get such results, and it may be that
these sensations when they are reported are of the associated variety.
In the case of certain abnormal nervous conditions, however, these
features may assume rather striking proportions. Thus, in the “auræ,” or
preliminary symptoms preceding an epileptic attack, the patient often
experiences unpleasant bitter or metallic tastes, and distressing
feelings of numbness of tongue, etc. These sensory manifestations are,
however, by no means as elaborate as are the “auræ” of some of the other
senses, notably hearing and vision.
_Partial and Complete Ageusia_
Conditions of partial or complete _ageusia_, or loss of taste, are well
known. Such conditions may result from the local application of various
drugs to the end organs, the paralyzing effect of drugs on the nerve
trunks, injury to, or operations on, these nerves, or damage through
injury, disintegration, or removal of special brain areas.
_Taste Hallucinations of the Insane_
In the case of the mentally deranged taste hallucinations are usually
disagreeable, and they are often rationalized into a fabric of
delusions,—foul gases are said to be blown upon them, poisons are being
placed in their food. Such patients behave in realistic manner, making
various defensive reactions, such as stuffing the nostrils with paper or
cloth, spitting, and refusing food. In some cases these hallucinations
of the insane obviously originate from local inflammation in the
peripheral tissues, or from glandular disturbances, and, hence, do not
in themselves constitute important pathological symptoms. In some cases,
however, such hallucinations arise quite independently of such acute
local conditions of irritation, as in chronic psychic disorders or
dementias. Under such circumstances they have greater significance, as
they point to more deep-seated mental and nervous disturbance. Just as
in normal life taste and smell are very closely associated with each
other, so, in these cases of insane hallucinations, disorders of taste
sensation are likely to involve olfactory irregularities as well.
_Synæsthesias of Taste_
An interesting though apparently somewhat rare phenomenon in the field
of sensation is what is known as “synæsthesia.” By this is meant cases
in which a given sense quality arouses, or is intimately associated
with, qualities belonging to other sensory modes. Thus, in the case of
vision and hearing, some individuals perceive the different vowel
sounds, or the sound of musical instruments, as having color. One such
person reports that to him all the consonant sounds seem to be very dark
purple, while among the vowel sounds “a” seems yellow, “e” is pale
emerald, and “u” is light dove color.
Taste, far from being an exception in this case, is one of the senses in
connection with which “synæsthesias” must often occur. Salt, for
instance, is described by one observer as dull red, bitter as brownish,
sweet as clear bright red, and sour as green or greenish-blue. To
another observer the taste of meats seems red or brown, the taste of
Graham bread is rich red in color, while all ice creams (except
chocolate and coffee) taste blue. To still another reporter the sound of
the word “intelligence” tastes like fresh sliced tomatoes, while the
sound of the word “interest” tastes like stewed tomatoes. There has been
much speculation as to the probable meaning and mechanism of these
synæsthetic experiences. Investigation seems to show that the particular
combinations are by no means universal, even among those who report such
observations,—they seem to be individual and personal in their nature
and presumably in their origin.
It seems quite probable that in the main these synæsthesias represent
uncritical confusion of sensory qualities with other sensory qualities,
or with the affective qualities, the feelings, which accompany them.
Thus, we often hear such phrases as “bright taste,” “heavy taste,” “dark
brown taste,” “green taste,” “soft taste,” “hard taste,” “smooth taste,”
etc. It is clear in most of these cases that either a touch component is
included in the total taste experience (as in “smooth taste,” “soft
taste,” “hard taste”), or that kinæsthetic (muscular) factors are so
included (as in “heavy taste”), or that the phrase is more or less
designedly an analogy, or other figure of speech (as in “sharp taste,”
“bright taste,” “clear taste”). The basis of such analogies is sometimes
rather easily discerned, and often is seen to be the “feeling tone”
which the sensation arouses,—the effect or “affect” which it produces.
Thus, a heavy weight retards, inhibits, and overpowers us. Some tastes
have this same overpowering affective tone, and may be intelligibly
described as “heavy.” A clear, bright day gives us recognizable feelings
of pleasantness, relief, and gives to objects a distinctness of contour.
Some tastes, being well defined, definitely localized, and highly
agreeable and soothing, may, then, be intelligibly described as being
“clear,” “bright,” or “pointed.” These illustrations represent, to be
sure, only simple forms of such synæsthesias. But even the resemblance
of the sound of “intelligence” to the taste of fresh sliced tomatoes is
by no means incomprehensible when we reflect that “freshness” means
“alertness,” “sliced” suggests sharpness of edge, while tomatoes thus
prepared are usually mature and ripe. For are not alertness, keenness,
and maturity the very marks of intelligence, just as “dullness” and
“greenness,” also sense qualities, are expressive of its absence? In
somewhat the same way we commonly speak of “sweet odors,” “sweet sounds
of music,” or even sweet visual experiences, as in “a sweet face.”
A few individual cases of taste synæsthesia have been studied in some
detail. Such individuals are often shown to have a defective sense of
taste and to rely largely, in their recognition of taste, on touch
accompaniments, affective characteristics, and such “color” experiences
as the various tastes are said to induce.
_Perversions of Taste_
Under certain unusual organic conditions, and also still more commonly
in the case of degenerate and neurotic individuals, various perversions
of taste occur. These perversions do not seem to be exclusively
gustatory in character, since they involve more general factors, such as
appetite, craving, and emotional disturbance. The name _parorexia_ is
sometimes given to these perversions of taste and appetite. One of the
subforms, known as _malacia_, takes the form of an urgent desire for hot
spices, or for sour and acid foods, such as pickles. What is known as
“salt hunger” is a very similar condition, especially often found among
the lower animals. Another form of such perversion, known as _pica_,
shows itself in the desire to eat such substances as clay, chalk, and
similar gritty or earthy substances. Especially often among children and
among certain primitive peoples the chewing of these substances often
seems to give a satisfaction quite unfamiliar to the majority of
mankind. Little is known about such perversions beyond the fact that
they have often been reported.
Under certain conditions of mental degeneracy and nervous disorder
perversions sometimes arise which have been classed under the term
_allotriophagia_. This perversion takes the form of eating with apparent
relish various kinds of filth which are commonly offensive and
disgusting. In these cases it is quite possible that there is no genuine
taste disorder. Many, if, indeed, not most, of our revulsions against
substances known as filth arise on the basis of associated
circumstances, rather than on the simple basis of their taste qualities.
The falling away, or deterioration, of these associative and æsthetic
controls in the case of the demented and degenerate, and their absence
in the case of the feeble-minded and imbecile, may easily lead to
reactions which suggest but do not necessarily involve genuine taste
disorder.
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