90 PSYCHOLOGICAL EFFECTS OF ALCOHOL. 



EFFECT OF ALCOHOL ON THE EYE-REACTION. 



Following our regular procedure of calculating the effects of alcohol 

 from the differences between the normal of the day and subsequent 

 periods, it appears from table 9 that the average effect of the smaller 

 dose of alcohol (dose A) is to decrease the reaction time in four cases out 

 of five, amounting to an average change of 13 a- or 5.4 per cent. The 

 effect of the larger dose of alcohol (dose B), on the other hand, is a length- 

 ening of the reaction time, in all six subjects, by 33 <r, or 15.6 per cent. 

 The psychopathic subjects show a slight (5 per cent) decrease of latency 

 like the main group after similar dosage. The effect of the 12-hour 

 experiments (dose C) is an increase of the reaction time in both subjects, 

 but the increase in the case of Subject IX is too slight to be significant. 



In general one must conclude that a dose of 45 c.c. of alcohol clearly 

 increases the latency of the eye-reactions. The effect of 30 c.c., on 

 the contrary, seems to be in the opposite direction. This corresponds 

 rather closely with the results of the simple reaction experiments by 

 Kraepelin. In conjunction with the data from other sources, we shall 

 discuss in the general summary (Chapter IX) whether or not our data 

 warrant the conclusion that the two doses of alcohol really affect the 

 complex nervous arc which is involved in eye-reaction in opposite ways. 



EFFECT OF ALCOHOL ON THE REACTION-TIME IN READING 



ISOLATED WORDS. 



There are very few mental operations which are comparable with the 

 reflexes in uniformity; very few that may be assumed to be even approx- 

 imately equally practiced in the experience of different individuals. 

 Probably the most nearly common element in the intellectual experience 

 of normal individuals in literate communities is the association between 

 visual, auditory, and motor symbols in language and the associations of 

 elementary mathematics. 



The computation experiments of Kraepelin and his pupils make use 

 of this community of elementary mathematical experience to measure 

 the effect of alcohol on controlled associations. But common experi- 

 ence, as well as laboratory experiment, makes it obvious that even 

 in the associations of elementary mathematics there are gross differ- 

 ences in the facility with which different individuals react to different 

 combinations. Even in the same subject, provided he is not specially 

 practiced, the difficulty of relatively simple mathematical tasks may vary 

 enormously. For example, the multiplication of 8X5 is commonly a 

 readier association than that of 8X7. Similarly 9+9 is commonly 

 readier than 7+6. The practice effects are, moreover, often enormous. 



Compared to even the simpler association tasks of mental arithmetic, 

 the association process which is involved in reading short, familiar 

 words seems easy to most subjects. For the average literate it is also 

 probably better practiced. Reading should consequently be a reaction 



