62 Effect of Alcohol on Psycho-Physiological Functions. 



period 6 shows a decrease of 1.9 per cent. The total average effect is 

 an increase of 10 per cent in the time of the eye reaction to peripherally 

 appearing stimuli as the result of 30 c.c. of absolute alcohol. 



There is, furthermore, a change in the mean variation as the result of 

 the ingestion of alcohol. This is shown by an increased variability — 

 that is, a larger fluctuation between successive reactions — which is 

 greatest in periods 2 and 3, 1 in which the values are respectively +34 

 and +41 per cent. The paucity of data for period 6 makes the results 

 for that period of slight value. With this subject, therefore, the eye- 

 reaction time shows a lengthening of from 12 to 13 per cent and an 

 increase in variability from 34 to 41 per cent in the first hour and one- 

 half following the ingestion of 30 c.c. of alcohol. 2 



REACTION TIME IN READING ISOLATED WORDS. 



In the word-reaction measurements the peripheral velocity of the 

 kymograph drum on which the moments of exposure of the word and 

 the reaction were registered was 100 mm. per second; the individual 

 reaction was therefore read by estimation to 0.1 mm., that is, 1 o\ 3 In 

 table 10, which shows the data and summary of the effect of alcohol 

 for this measurement, the unit used is therefore 0.001 second. This 

 table presents the material by periods and, like the preceding tables, 

 is divided into three sections, these giving the actual reaction aver- 

 ages, the differences, and the effect of alcohol by differences and 

 percentiles, with the probable correctness of these true differences. 

 The table contains no statement of false reactions — that is, the pro- 

 nunciation of the wrong word — as it rarely occurred. This may be 

 supposed from the usual reaction-time averages shown, as the mean 

 variation within the 24 reactions of a single period fluctuates from 19 

 to 44 a for normal periods, i. e., from 4 to 9 per cent of the reaction 

 time. The average mean variation is practically 6.5 per cent of the 

 average normal reaction time. 



In striking contrast to the result found for the effect of alcohol on the 

 eye reaction to peripheral stimuli, the word reactions following alcohol 

 were undoubtedly faster on the average for all days than those for the 

 same periods on normal days. According to the figures in the next 

 to the last column, the average reaction time for the three normal days 



1 The eye-reaction measurement was the seventh measurement in the cycle and came approxi- 

 mately 30 minutes after the beginning of the period; therefore, in period 2 the measurement was 

 made 30 minutes after the taking of the alcohol. 



2 The particularly low average reaction-time of 159 a for Subject VI on the second day in the 

 first series of experiments (see Dodge and Benedict's report, p. 85, table 7) is decidedly the smallest 

 average in the first series of experiments with Subject VI. It is to be noted that if the average 

 values for dose A given in their table 8 (p. 88 of their report) were averaged, omitting this one, the 

 result would be 216 a, which is the same value as that given for the first normal day. (See same 

 table.) 



3 A typical record of a word-reaction experiment is shown in Dodge and Benedict's report, 

 opposite page 101, in figure 22. 



