CHAPTER IX. 



SUMMARIES AND CORRELATIONS. 



DIFFERENTIAL INCIDENCE OF THE EFFECTS OF ALCOHOL. 



The first attempt to measure the relative incidence of the effect of 

 alcohol on various fundamental mental processes is the classical work of 

 Kraepelin. 1 In this task he was a pioneer. Since his work there have 

 been numberless special investigations of the action of alcohol on various 

 mental operations, but there have been no systematic groups of experi- 

 ments that permitted an inference as to the relative incidence of the 

 alcohol effect. 



The well-known conclusions of Kraepelin may be condensed as 

 follows : All doses of alcohol depress the intellectual processes of appre- 

 hension, memory, and judgment. Small doses facilitate motor dis- 

 charge at first and subsequently depress it. Large doses depress both 

 intellectual and motor processes from the first. The nature and amount 

 of the effects depend on the characteristics of the individual and on his 

 condition. 



Certain apparent discrepancies between our results and his led us 

 to a careful review of Kraepelin's original arguments. In that review 

 two factors challenged our attention, viz, (1) the neural complexity of 

 all his experimental processes, and (2) the unsatisfactoriness of some 

 of his analyses as judged by present standards. For example: As 

 experimenter and as theorist, Kraepelin worked under the tradition of 

 a complete differentiation of the sensory and motor factors in reaction. 

 Choice and discrimination were for him real factors in the reactions 

 called by these respective names. It is now generally realized, however, 

 that choice is not discoverable in the consciousness that accompanies 

 the practiced so-called choice reaction, and that the discrimination 

 reaction is complicated by notable inhibitory tendencies that are in 

 their nature motor rather than discriminatory. But from his stand- 

 point, Kraepelin was able to say without hesitation that the difference 

 between the results of the discrimination reaction and those of the 

 simple reaction can be referred only to the new factor which it was 

 intended to introduce into the process, viz, the discrimination. Conse- 

 quently, since the " discrimination " appears to be lengthened by alcohol, 

 he holds that the intellectual factor in reaction processes is paralyzed 

 by alcohol. Similarly, since the intentionally new factor in the choice 

 reaction is primarily a motor process, and since the choice reactions 

 are shorter in his experiments after alcohol, he held that the discharge 

 of motor processes is facilitated by moderate doses of alcohol. Con- 



1 Kraepelin, Wundt's Phil. Studien, I, 1883, p. 573. Ueber die Beeinflussung einfacher 

 psychischer Vorgange durch einige Arzneimittel. Jena, 1892. 



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