It is even questionable whether the energy derived from the oxidation of alcohol in the body can be directly used at all as a source of muscular energy. Such competent observers as Schumberg and Scheffer independently reached the conclusion that it cannot. Dr. Abel inclines to the same opinion. He suggests that "alcohol is not a food in the sense in which fats and carbohydrates are food; it should be defined as an easily oxidizable drug with numerous untoward effects which inevitably appear when a certain minimum dose is exceeded," He thinks that alcohol should be classed "with the more or less dangerous stimulants and narcotics, such as hasheesh, tobacco, etc., rather than with truly sustaining foodstuffs," Some of the grounds for this view will appear presently, as we now turn to examine the alleged stimulating effects of alcohol upon the mental processes.
Alcohol as a Brain Stimulant
The celebrated physicist Von Helmholtz, one of the foremost thinkers of the nineteenth century, declared that the very smallest quantity of alcohol served effectively, while its influence lasted, to banish from his mind all possibility of creative effort; all capacity to solve an abstruse problem. The result of recent experiments in the field of physiological psychology convince one that the same thing is true in some measure of every other mind capable of creative thinking. Certainly all the evidence goes to show that no mind is capable of its best efforts when influenced by even small quantities of alcohol. If any reader of these words is disposed to challenge this statement, on the strength of his own personal experience, I would ask him to reflect carefully as to whether what he has been disposed to regard as a stimulant effect may not be better explained along lines suggested by these words of Professor James: "The reason for craving alcohol is that it is an anesthetic even in moderate quantities. It obliterates a part of the field of consciousness and abolishes collateral trains of thought."
The experimental evidence that tends to establish the position of alcohol as an inhibitor and disturber rather than a promoter of mental activity has been gathered largely by German investigators. Many of their experiments are of a rather technical character, aiming to test the basal operations of the mind. Others, however, are eminently practical, as we shall see. The earliest experiments, made by Exner in Vienna so long ago as 1873, aimed to determine the effect of alcohol upon the so-called reaction-time. The subject of the experiment sits at a table, with his finger upon a telegraph key. At a given signal—say a flash of light—he releases the key. The time that elapses between signal and response—measured electrically in fractions of a second—is called the simple or direct reaction-time. This varies for different individuals, but is relatively constant, under given conditions, for the same individual. Exner found, however, that when an individual had imbibed a small quantity of alcohol, his reaction-time was lengthened, though the subject believed himself to be responding more promptly than before.
These highly suggestive experiments attracted no very great amount of attention at the time. Some years later, however, they were repeated by several investigators, including Dietl, Vintschgau, and in particular Kraepelin and his pupils. It was then discovered that, in the case of a robust young man, if the quantity of alcohol ingested was very small, and the tests were made immediately, the direct reaction-time was not lengthened, but appreciably shortened instead. If, however, the quantity of alcohol was increased, or if the experiments were made at a considerable interval of time after its ingestion, the reaction-time fell below the normal, as in Exner's experiments.
Subsequent experiments tested mental processes of a somewhat more complicated character. For example, the subject would place, each hand on a telegraph key, at right and left. The signals would then be varied, it being understood that one key or the other would be pressed promptly accordingly as a red or a white light, appeared. It became necessary, therefore, to recognize the color of the light, and to recall which hand was to be moved at that particular, signal: in other words, to make a choice not unlike that which a locomotive engineer is required to make when he encounters an unexpected signal light. The tests showed that after the ingestion of a small quantity of alcohol—say a glass of beer—there was a marked disturbance of the mental processes involved in this reaction. On the average, the keys were released more rapidly than before the alcohol was taken, but the wrong key was much more frequently released than under normal circumstances. Speed was attained at the cost of correct judgment. Thus, as Dr. Stier remarks, the experiment shows the elements of two of the most significant and persistent effects of alcohol, namely, the vitiating of mental processes and the increased tendency to hasty or incoördinate movements. Stated otherwise, a levelling down process is involved, whereby the higher function is dulled, the lower function accentuated.
Equally suggestive are the results of some experiments devised by Ach and Maljarewski to test the effects of alcohol upon the perception and comprehension of printed symbols. The subject was required to read aloud a continuous series of letters or meaningless syllables or short words, as viewed through a small slit in a revolving cylinder. It was found that after taking a small quantity of alcohol, the subject was noticeably less able to read correctly. His capacity to repeat, after a short interval, a number of letters correctly read, was also much impaired. He made more omissions than before, and tended to substitute words and syllables for those actually seen. It is especially noteworthy that the largest number of mistakes were made in the reading of meaningless syllables,—that is to say, in the part of the task calling for the highest or most complicated type of mental activity.
Another striking illustration of the tendency of alcohol to impair the higher mental processes was given by some experiments instituted by Kraepelin to test the association of ideas, In these experiments, a word is pronounced, and the subject is required to pronounce the first word that suggests itself in response. Some very interesting secrets of the subconscious personality are revealed thereby, as was shown, for example, in a series of experiments conducted last year at Zürich by Dr. Frederick Peterson of New York. But I cannot dwell on these here. Suffice it for our purpose that the possible responses are of two general types. The suggested word being, let us say, "book," the subject may (1) think of some word associated logically with the idea of a book, such as "read" or "leaves"; or he may (2) think of some word associated merely through similarity of sound, such as "cook" or "shook." In a large series of tests, any given individual tends to show a tolerably uniform proportion between the two types of association; and this ratio is in a sense explicative of his type of mind. Generally speaking, the higher the intelligence, the higher will be the ratio of logical to merely rhymed associations. Moreover, the same individual will exhibit more associations of the logical type when his mind is fresh than when it is exhausted, as after a hard day's work.
In Kraepelin's experiments it appeared that even the smallest quantity of alcohol had virtually the effect of fatiguing the mind of the subject, so that the number of his rhymed responses rose far above the normal. That is to say, the lower form of association of ideas was accentuated, at the expense of the higher. In effect, the particular mind experimented upon was always brought for the time being to a lower level by the alcohol.