168 PSYCHOLOGICAL EFFECTS OF ALCOHOL. 



arrangement; it would give valuable data not only with respect to 

 oscillation frequency, but with respect to the onset of fatigue and the 

 rapidity of recovery. The insurmountable difficulty in this arrange- 

 ment was that it proved impossible to secure maintained maximum 

 effort from our subjects for 30 consecutive seconds. Unintentionally 

 perhaps, but none the less really, some tended to adopt an initial speed 

 that they could maintain. Spurts appeared from uncontrolled sources. 

 Some may have been purely physiological. Some were clearly connected 

 with the feeling that the effort had lapsed. In connection with the 

 related but more complex tapping test, Wells states (p. 356): "The 

 feelings of annoyance arising from a long-continued test make it desir- 

 able that the experiment should be one giving the requisite data in 

 as short a time as possible." This may be generalized as follows : Every 

 consideration, practical as well as theoretical, demands the shortest 

 experimental period that will give the requisite data. In this particular 

 case, spurts and variability due to discomfort and other causes were 

 enormously reduced by adopting shorter experimental periods of 8". 

 That these shorter periods were in fact more satisfactory than the 30" 

 periods appears from the relative uniformity of the results. 

 ^Even in this relatively short experimental time, a regular decrement 

 in the speed of oscillation, as measured by 2" intervals, shows the 

 beginning of a fatigue process. Regularity in the onset of this fatigue 

 process is our best insurance against initial indifference, and sub- 

 maximal finger-movements. If no fatigue occurs, one suspects initial 

 indifference. But if the fatigue drop is regular and normal, initial 

 shirking is improbable, since it is beyond the capacity of an ordinary 

 subject to simulate this gradual onset of fatigue. 



Other forms of incomplete adaptation to the experimental conditions 

 are less easily determined. Correlated pulse- and respiration-rate should 

 be worth something in this respect as an indicator, but our knowledge 

 of the pulse-changes due to effort allows at present no numerical correc- 

 tion of results from this source. A variable interplay of changed 

 attention, effort, and adaptation to the experimental conditions must be 

 admitted as a possible, if not an inevitable, source of disturbance of the 

 results of the finger-movement tests. If our cases are sufficiently 

 numerous, however, accidental disturbances of this sort should compen- 

 sate and leave the general tendency of alcohol, both in direction and 

 amount, clearly marked. 



TECHNIQUE. 



For purposes of comparison with existing data, our measurements 

 of the most rapid possible reciprocal innervation of the finger may be 

 regarded as the tapping test reduced to its simplest form. As ordinarily 

 used, the "tapping test" measures the number of electric contacts that 

 can be made by the subject, either between a stylus and a plate, or by 

 the closure of a telegraph-key. Several considerations combine to 

 make both of these processes physiologically unsatisfactory : 



