132 



PSYCHOLOGICAL EFFECTS OF ALCOHOL. 



EXPERIMENTAL PROCEDURE. 



The subject sat before a horizontally placed Blix-Sandstrom kymo- 

 graph, in line with its axis of rotation in position I (fig. 1); through a 

 slit 14 mm. wide in the cylindrical screen, which was concentric with 

 the kymograph drum, a series of 4-letter words was exposed backwards, 

 i. e., in such a way that the last letter of each word appeared in the slit 

 of the screen first and the first letter appeared last. A series consisted 

 of 12 words. Each series was repeated 3 times. During the first 

 reading of the series each word must have been completely exposed 

 before the first letter was known and before the word was spoken. In 

 the two succeeding readings, residua of the first series effected a certain 

 saving in reaction-time. The word might then be spoken while one or 



TABLE 21. Effect of alcohol on memory. 

 [Average values given in thousandths of a second.] 



1 Effect on the average saving equals alcohol average minus normal 

 average. 



2 Percentile effect equals the effect of alcohol on the average saving 

 divided by the average saving of the corresponding normals of the day. 



more of the letters were still hidden. In a perfect score each word was 

 spoken before any letter appeared on the second or third exposure. 

 Perfect scores often occurred for the first word of a series. Only one 

 subject regularly achieved perfect scores for practically all the series 

 in three exposures. The saving in reaction-time between the first and 

 the two succeeding exposures is regarded as a measure of the advance- 

 ment of the memorizing process. 



With the drum revolving at the rate of 10 mm. per second and the 

 words 4 cm. apart, the time-interval from the beginning of one word to 

 the beginning of the next was 4". The duration of the whole series was 

 48" for the words, plus 2" for the spare space at the end of the series. 

 The whole memory experiment of three repetitions thus lasted about 

 3 minutes. The relative shortness of the experiment is of double 

 advantage; it not only conserves time during the experimental period, 



