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.