Lid Reflex. 



57 



preceding or accompanying the reflex decrease the latent time by 

 about 6 a, and increase the amplitude 3 to 4 mm. Whether or not 

 this is a characteristic phenomenon for the optic lid reflex must be 

 settled in the light of more extensive records. Those available show 

 consistently this difference. In making the comparison the lid-reflex 

 curves were of course not reread, but the original measurements were 

 placed in the appropriate columns and averaged. No average was 

 attempted for the second reflex. As the amplitude of this reflex is 

 usually quite small and the departure of the curve from the base line 

 consequently more gradual, there is admittedly a larger degree of error 

 ^determining the latency for these reflexes. 1 



Table 8. — Effect of voluntary lid movement upon latency and amplitude of the lid reflex. 



Since the alcohol during the first hour following ingestion causes a 

 marked decrease in the anticipatory voluntary lid movement in the 

 case of Subject VI, and since the lid reflexes which are not preceded by 

 such voluntary lid movements are, on the average, 5 to 7 <x longer in 

 latency with a somewhat decreased amplitude, that is, 3 to 4 mm., it is 

 quite apparent from a study of section in in table 5 that the effect of 

 alcohol in periods 2 and 3 on the latency and the amplitude of at least 

 the primary reflex might be ascribed wholly to this cause. 



Dodge and Benedict found that their Subjects IV and X were excep- 

 tional, as in both cases the reflex latency was decreased and the amplitude 

 of response increased following the alcohol. (See table 6, p. 71, of their 

 report.) Subject VI, dose A, is in line with the normal group and with 

 these later findings in showing a decreased amplitude for A and A' fol- 

 lowing the alcohol. He, however, formerly showed also a decreased 

 latency for L and I/. This is opposed to our later results, but must be 

 considered as more or less of an accident dependent upon the distribu- 

 tion of the voluntary winking and its effect upon the determination of 

 the latency. It so happened that the first-period values for October 

 22 and 29, November 5 and 12, 1913, were quite unequally affected by 

 this factor of anticipatory voluntary winking. On October 22 three of 

 the first four records were preceded by a voluntary wink. One of them 



1 Dodge, Am. Journ. Psychol., 1913, 26, p. 5. 



