80 Effect of Alcohol on Psycho-Physiological Functions. 



time revealed the mark at the right to which the subject was to move 

 his eye. The movement of the eye to this mark is shown in the first 

 short horizontal line to the right connecting the first vertical line with 

 the second vertical line. These vertical lines are of course made up of 

 dots, the light being interrupted by the tuning fork. These dots would 

 appear individually if the plate had been falling at a faster speed, as was 

 the case when the record of the eye reaction was taken. Having seen 

 the mark at the right, the subject looks to the one at the left, which was 

 placed at a distance of 40° on his arc of vision. The line of dashes con- 

 necting show the course of the movement and its speed, as each dash 

 with one interspace represents 0.01 of a second. From the left the eye 

 again moves to the right, and so on throughout the period of 5 seconds 

 allotted for this series of movements. 



The record at the extreme left (A) in figure 8 may be taken as a typi- 

 cal eye-movement record. 1 It was obtained in the first series of experi- 

 ments for this subject on February 12, 1914, and is better than any 

 record which the subject made in the second series and also better than 

 80 per cent of his earlier records. The vertical lines (periods of fixation) 

 which separate the movements show that in almost every case there was 

 readjustment, that is, correction for accurate fixation, following the 

 main movement. 2 The correction indicates that usually the saccadic 

 movement was not sufficient to bring the line of regard to the mark. 

 Such correction Dodge has designated as "plus correction," and it is a 

 normal phenomenon. The six other records shown in figure 8 (B, C, 

 D, E, F, and G), which are for July 4, periods 1 to 6 in order, show clearly 

 a general appearance which is different from record A. There are 

 almost no corrective movements at the end of the long eye movements ; 

 the amplitude is irregular and nearly always short. There are very 

 frequent breaks in the records caused by winking (for example, see W 

 on record B of figure), a factor which gave considerable difficulty not 

 only in this measurement but also in the lid-reflex records. The pho- 

 tographic tracing immediately preceding a wink, if part of a vertical 

 line, is usually heavy; if it is part of a horizontal line there is a curve 

 downward, showing a tendency for an upward movement of the eye. 



The records were nearly all legible, but the irregularity exemplified 

 in those shown, which is typical for this series, made it evident that if 

 the records were to be used it must be on a somewhat different basis 

 from that in the previous research, as we were dealing with many differ- 

 ent amplitudes of movement. In the six illustrated records from this 

 series of experiments (See B to (?) it is plain that the first movement to 

 the left is usually of fairly regular amplitude. If we use record a 

 as a standard for amplitude, measurement shows that the amplitude in 



1 The first of the record is slightly complicated, as it was re-exposed and shows part of a second 

 series of movements. See also Dodge and Benedict, p. 154, fig. 27, for another typical record. 



2 The corrections were measured in millimeters, converted into degrees, and recorded in the 

 tables of Dodge and Benedict's report. 



