72 PSYCHOLOGICAL EFFECTS OF ALCOHOL. 



(II) In the case of the psychopathic subjects the average results 

 are in the same direction as those of the normal group. The 12-hour 

 experiments with the normal subjects are evenly divided; Subject IX 

 follows the average, and Subject VI opposes it consistent with his 

 other records. 



(III) Since an increased latency and a decreased amplitude of reflex 

 movement are the usual physiological indicators of decreased reflex 

 excitability, we must conclude that in the case of the protective 

 lid-reflex, as in that of the patellar reflex, moderate doses of alcohol 

 tend to depress the excitability of the reflex arc. In the case of the lid- 

 reflex, where the data include the effects of both the 30 c.c. and the 

 45 c.c. doses, the average depression varies directly with the dose. 



(IV) The effect of alcohol on the refractory phase, as that is indi- 

 cated by the reflex response to the second stimulus, is less uniform. 

 After the 30 c.c. dose, both the first and the second reflexes are affected 

 in the same direction. The percentile decrease in amplitude of the 

 second reflex response is conspicuously high. After the 45 c.c. dose, 

 on the contrary, the latency of the second reflex is actually decreased, 

 while the amplitude is decreased, but less than half what it was after 

 the 30 c.c. dose. The refractory-phase data are neither regular nor, 

 since they represent only a single interval, can they be regarded as final. 

 But they are certainly suggestive and seem to indicate an important 

 lead for the investigation of individual differences in the action of 

 drugs. If, as we assume, the refractory phase is an index of fatiga- 

 bility, the enormous individual variation in the effect of alcohol on the 

 refractory phase of the reflex arc is evidence that the discrepancy 

 between various studies of the effect of alcohol on fatigue is not an 

 accident of experimental technique, but a result of actual individual 

 differences. In the second place, our data seem to indicate that while 

 both the first and second reflex responses are depressed in extent by 

 both doses of alcohol, the larger dose with practically every subject has 

 a less depressing effect on the latency of the second response than the 

 first. The hypothesis suggests itself that one is approaching the border- 

 line between refractory phase and summation. In the former, response 

 to the first stimulation lessens response to the second; while in the 

 latter, the effect of the first stimulus operates to augment the response 

 to the second. Such border-lines or critical points are often found in 

 the systematic variation of the interval between the first and second 

 stimulation. Moreover, under normal conditions it regularly occurs 

 that, when from some unknown cause the first response is unusually 

 slight, the second may be higher than the first. It appears that with 

 the larger dose, when the first response is conspicuously decreased, the 

 second begins to be less depressed. These facts suggest the further 

 hypothesis that the alcohol depression of the reflexes is more like a 

 decrease in the readiness of the arc than a real paralysis. They suggest 



