52 Effect of Alcohol on Psycho-Physiological Functions. 



noticeable difference between the two intensities of stimulation, that is, 

 30-gram and 50-gram hammers. The lid reflexes, on the other hand, 

 show an average mean variation of about 3 a, with a somewhat larger 

 average for L' (see particularly period 1 for both normal and alcohol 

 days) . This difference is all the more significant when it is considered 

 that the protective lid-reflex records permitted more accurate measure- 

 ments than the kymograph records for the patellar reflex. On the 

 other hand, only four lid reflexes were measured in each period, and 

 these could not follow each other so closely, because for each record a 

 separate strip of photographic paper held in a plate-holder had to be 

 exposed and in turn covered and withdrawn before the next reflex could 

 be taken. This interruption between lid reflexes with the necessary 

 manipulation of the camera and the plate-holders provided time and 

 occasion for more extraneous agencies to act upon the subject, influ- 

 encing the process considered. With the knee-jerk measurement the 

 reflexes followed each other with great regularity. There was little 

 to attract the attention of the subject save the stimulation blows, and 

 relaxation was favored by the general bodily position, since he reclined 

 in a steamer chair. During the measurement of the lid reflex the sub- 

 ject sat upright, held his head steadily in a rest, looked at a fixation 

 mark, and counted backwards from a number which was given previ- 

 ous to the release of the camera. All of this demanded more atten- 

 tion and cooperation on the part of the subject than was needful in the 

 measurement of the patellar reflex. 



Associated with the attitude of attention necessary on the part of the 

 subject for these measurements there was, in the case of Subject VI, a 

 large amount of anticipatory voluntary lid movement. If, as will be 

 shown later, these voluntary movements have an influence upon the 

 latency of the reflex, we have a group of conditions which offer ample 

 explanation for the larger mean variation in the latency of the lid reflex. 

 There is no such large discrepancy in the average mean variation for 

 the amplitude of the two reflexes, although here again the larger varia- 

 tions are found in the case of the lid reflex. It is further to be noted 

 that the mean variations for the latency and amplitude of the lid reflex 

 are not so large in those periods which follow the ingestion of alcohol. 



The effect of alcohol upon the protective lid reflex may be seen in 

 section in in both tables 5 and 6. For convenience of comparison the 

 percentile effects are also given in diagrammatic form in figures 4 and 

 5, which show the latency and amplitude, respectively. The solid line 

 represents the percentile effect on the primary reflex, the broken line 

 the reflex in the refractory phase. From figure 4 it is evident that the 

 latency of the reflex is considerably lengthened in those measurements 

 which follow immediately the taking of alcohol (lid reflexes were never 

 measured earlier than 40 minutes after the dose). In period 3 the 

 latency is still lengthened, but not in such a marked degree. There is 



