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 Mode | 381 Dreams | 300 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.