Tests of Quickness.

A preliminary statement is here given of a series of experiments which are being made at the Physiological Laboratory of the Scientific School.

Three tests are made: first, the time required for a response to a bell signal; second, the quickness and speed of a blow struck in response to a singal; and third, the time and accuracy of attempts made to touch a dot suddenly shown in an unexpected position.

The following table gives the results of the first and second of these tests, the time being calculated in hundredths of a second:

Time. Bell. Quickness of blow. (Starting time. Speed (40 cm.)

Average, 14.3 19.7 11.4

Shortest, 11.0 14.0 8.0

Longest, 17.0 24.5 13.5

The tests of quickness and accuracy in touching a dot were made in three positions; immediately in front of the subject, and to the right and left of it. A dot was suddenly shown in one of these positions by the dropping of a small screen placed before it, and the subject then endeavored to strike it as quickly and accurately as possible. The time was then secured in thousandths of a second, and the error of touching was calculated in millimeters. The following table shows the time for the two hands in these different positions:

Right hand. Left hand. Position. Time Error Time Error Position. (sec.) (mm.) (sec.) (mm.)

Center, .376 8 .386 8

Right, .437 14 .458 16

Left, .439 10 .418 18

Average, .413 11 .420 12

With the right hand in the right position there is a range in time from .294 to .551 seconds, in center position from .205 to .523 seconds, and in left position from .311 to .654 seconds, with an average from .270 to .576 seconds. The corresponding range in error is 5 to 43 mm., 4 to 16 mm., 3 to 21 mm., and an average 5 to 22 mm. With the left hand in the same positions the corresponding ranges are .346 to .629 sec., .239 to .583 sec., .285 to .571 sec., which gives a lowest average of .340 sec., and a highest average of .594 sec. The range of error corresponding to these times is 4 to 44 mm., 3 to 15 mm., 6 to 24 mm., and an average from 5 to 21 mm.

The quickest reactions in all positions and tests were found to be given by a single individual as were also the slowest. The slightest and greatest errors are more scattered among the subjects. The range of individual variation in quickness and accuracy is sufficient to determine the position of any given subject in the series.

It is hoped that a series of records may be secured in sufficient numbers to make possible a study of the correlation of these variations with the attainments of the individuals in such pursuits, whether of business or sport, as require quickness and accuracy.

A complete table showing the individual results of the different men examined has been posted in the Physiological Laboratory of the Scientific School.