16 PSYCHOLOGICAL EFFECTS OF ALCOHOL. 



tigate elementary neuro-muscular processes in their simplest available 

 form, and of the more complex processes to choose those involving as few 

 unknown factors as possible. In particular we have tried to measure 

 processes that were as insusceptible as possible to direct and arbitrary 

 conscious modification, and as free as possible from uncontrollable 

 influences of bias, effort, and attention. We thus tried to avoid the 

 occasion for most of the adverse criticism that has been directed against 

 earlier researches on the psychological effects of alcohol. This second 

 principle led us to lay particular emphasis on the simplest reflex arcs 

 as a precondition for interpreting the complicated reactions. In addi- 

 tion to the accuracy and simplicity of the photographic technique, the 

 freedom of the processes from arbitrary modification led us to measure 

 the velocity of the eye-movements in preference to the movement of 

 members which are more subject to voluntary control. The same 

 principle of simplicity led us to measure the sensory threshold for 

 Faradic stimulation in preference to those sense thresholds which are 

 complicated by more or less elaborate adaptive mechanisms, as in 

 vision; or by the irregular interplay of related sense data, as in the 

 pressure threshold. On the negative side, this principle led us to ex- 

 clude a considerable number of familiar techniques, the most conspicu- 

 ous example of which is the ergographic experiment. In addition to the 

 fact that any ergographic data which we might collect would add rela- 

 tively little to the mass of more or less conflicting data already at hand, 

 and quite apart from the purely mechanical difficulties in the operation 

 of the ergograph and in the interpretation of the resulting data, we were 

 disinclined to use that instrument because of the fundamental difficulty 

 of disentangling the numerous physiological and psychological factors 

 that unite to produce any specific ergographic accomplishment. 1 On 

 similar grounds, any measurements involving long-sustained attention 

 or effort, or indifference to increasing discomfort, without opportunity 

 for adequate, objective control, seemed undesirable. But obviously, 

 even at best, in view of recent analyses of neuro-muscular processes, 

 such as those of Sherrington, 2 Verworn, 3 and Isserlin, 4 simplicity can 

 be no more than a relative term. We must concede that the action of 

 even the simplest spinal arcs is normally dependent on the interplay 

 of an indefinite number of inhibiting and reinforcing conditions that 

 can never be entirely eliminated. The action of the higher nervous 



lr The attempt of Mile. Joteyko (Joteyko, Travaux du Laboratoire de Physiologic, Instituts 

 Solvay, Brussels, 1904, 6, p. 361) to give a mathematical expression to the interrelationship of 

 central factors, the effects of exhaustion, and the intoxication by fatigue products must be regarded 

 as suggesting a direction of investigation rather than as establishing a technique. At the present 

 time, at least, her original analysis can not be said to supply a reliable instrument for general 

 application to ergographic curves. The classical analysis of the fatigue curve by Kraepelin 

 shows how complex may be the interplay of the various factors. 



2 Sherrington, Integrative Action of the Nervous System, New York, N. Y., 1907. 



'Verworn, Irritability, New Haven, 1913; Verworn, Erregung und Lahmung, Jena, 1914. 



4 Isserlin, Psychol. Arbeiten, 1914, 6, pp. 1 to 196. 



