The testimony of daily experience would probably be at once that the various elementary tastes may combine to produce new tastes of a more complex or even of a unitary character. Thus, the taste of lemonade is distinctive enough. Yet even casual observation suffices to show that the sweet and the sour components have by no means lost their identity, since each can be singled out in attention and recognized as the familiar elementary quality. Red and blue may fuse to produce a violet or a purple from which the original elements can by no means be singled out and identified through direct inspection. But it seems to be the rule that tastes do not behave in this way, although the demands of daily experience do not readily lead us to discover the fact. “Think, for instance,” writes Titchener, “of the flavor of a ripe peach. The ethereal odor may be ruled out by holding the nose. The taste components,—sweet, bitter, sour,—may be identified by special direction of the attention upon them. The touch components—the softness and stringiness of the pulp, the puckery feel of the sour—may be singled out in the same way. Nevertheless, all these factors blend together so intimately that it Is hard to give up one’s belief in a peculiar and unanalyzable peach flavor. Indeed, some psychologists assert that this resultant flavor exists; that in all such cases the concurrence of the taste qualities gives rise to a new basic or fundamental taste, which serves, so to say, as background to the separate components. There is, however, no need to make any such assumption. It is a universal rule in psychology that when sense qualities combine to form what is called a perception, the result of their combination is not a sum but a system, not a patchwork but a pattern.... Hence, just as it would be absurd to say that the plan of the locomotive is a new bit of steel or the pattern of the carpet a new bit of colored stuff, so is it wrong to say that the peach character of a certain taste blend is a new taste quality.”
The mixture of stimuli provoking two taste qualities does not, then, produce intermediate qualities such as the orange which results from the mixture of red and yellow. Instead, in this case, the two qualities do one of these three things: (a) they may remain separate and distinct; (b) they may fluctuate individually and alternate with each other in their appearance; (c) they may tend to neutralize each other. If the stimuli are very intense, oscillation is the common result. If the stimuli are weak, some degree of neutralization is reported to be the rule. Only in one case, namely, the mixture of sweet and salt, does a new taste seem to emerge, which does not resemble either of the original qualities. Kiesow finds that such a mixture, in the case of weak solutions, gives rise to a quality described as “flat,” “vapid,” or “insipid,”—the alkaline taste which we have already considered.
Compensation, Antagonism, and Neutralization
In the case of color, there may be found for every quality or mixture an opposite quality or mixture which when combined with the former either completely neutralizes it or at least reduces its intensity. Thus blue and yellow, of the proper tones and proportion, cancel each other, leaving only an experience of gray. So do a certain olive color and a particular violet, a certain orange and a particular bluish-green, a certain red and a particular green.
We have already suggested that in case of weak taste qualities a similar effect is present. “With the low intensities there is in most cases a partial compensation, which is least for sweet and sour, better for salt and bitter, better still for sour and bitter, sour and salt, sweet and bitter.” These facts are utilized in daily life in the countless combinations of dressings, sauces, seasonings and condiments used in the preparation of food. We take sugar with our tea, our coffee, our chocolate, our strawberries, our grapefruit, and our lemon juice, and realize that it to some degree counteracts or neutralizes the bitter or the sour taste of these foods in their original form. “Salt corrects the sweetness of an over-ripe melon.” In our salad dressings, sauces, gravies, relishes, and bitters we find the means of reënforcing or toning down the taste qualities to suit our own particular fancy.
In part, of course, these effects are not achieved through the mere process of neutralization. The addition of touch qualities, such as the pucker of vinegar, the sting of pepper, the bite of mustard, and the burn of onion, plays its own part in the constitution of a flavor, regardless of their compensating influence on the pure taste qualities.
In line with the fact that taste and odor are easily confused, and contributing perhaps to this confusion, is the fact that tastes and odors are related to each other through their antagonism, almost if not quite as definitely as are the qualities within each of the separate modes. Thus, the sickening odor of many medicines is somewhat palliated if they are taken in fermented juices or with the sour acids of fresh fruits. “Quinine, which tastes bitter and has no smell, is corrected by essence of orange peel, which has an aromatic smell and no taste.” Titchener pertinently remarks that these results may in part arise from the simple process of distracting attention from an unpleasant item to a more agreeable part of the experience. On the other hand, the special effectiveness of the introduction of odors into the complex rather than pleasant sights and sounds suggests that the results in the case of taste and smell are not solely a matter of attention, but are in part, at least, dependent on the essential relationships between the qualities of these two modes of sensation. In the chapter on “The Evolution of Taste” certain light is thrown on the closeness of these relationships by our knowledge of the intimate biological connection between taste and smell. In certain lower forms of animal life it is indeed quite impossible to draw any clear line between these two features of “the chemical sense.”
In general, then, although the facts of compensation, antagonism, and complementariness are to be observed within the field of the taste qualities, the relations disclosed are by no means as definite nor as systematic as they are in the case of vision. For a given primary color quality there exists only one other elementary quality which stands to it in the relation of antagonist. But we have seen that in the cases of both sour and bitter there is at least some degree of antagonism with all three of the other qualities, while both sweet and salt antagonize in some degree both sour and bitter. Moreover, at least the sour, the bitter, and the sweet appear to show antagonistic relations to certain qualities of smell.
In none of these cases has there been presented clear evidence showing the ability of one quality to totally efface another, so that no taste whatever is present. In the case of colors, however, the result of such combinations in the right proportions may easily be a total absence of color quality. It is true that occasional instances of such effects in taste have been reported, but the general rule seems to be that the extreme degree of neutralization leaves an experience which is recognized as a taste, but which is described as “flat” or as “insipid.” It is possible, of course, that this “insipid” taste quality is the tactile and kinæsthetic residue of the total experience, much as the “gray” which results from the combination of complementary colors may be described as the brightness residue of the total momentary effect. But in the latter case the residue would be distinctly “visual” although not “color.” In the case of taste nothing corresponding to the “brightness” of vision is recognized, and the residue as we have described it would consequently belong to a different mode of sensation.