538 PROGRESS OF ANTHROPOLOGY IN 1X90. 



the motor and sensory tracts of tbe spinal cord has tlms been deter- 

 mined. In a second series of experiments two stimnli are given at dif- 

 ferent parts of the body, and the interval between them adjusted until 

 the observer seems to perceive them simultaneously. It is thou<;ht 

 that these experiments will throw more lijiht on human pliys!oloj;y 

 than cases in which the nerve (motor only) uf a partly dead frojj is 

 artiticially stimulated. The times are also of interest to psychology, 

 as they are needed in order to determine purely mental times. Mr. 

 Witmer is measuring the personal ditierence in reaction-times, ami the 

 work will be extended to different mental processes. These times seem 

 to vary with age, sex, nationality, education and occupation, and their 

 study may have practical value as well as theoretic interest. Length 

 of life should be measured by rate of thought. Experiments are also 

 being made on the variation in the reaction-time from hour to hour and 

 day to day. With the co-operation of Dr. Weir .Mitchell and other 

 eminent neurologists the alteration in the time of physiological proc- 

 esses in diseases of the nervous system is being studied. It is believed 

 that such tests may be of use in diagnosis. The nervous impulse may 

 be sent through the system in different directions until a relative delay 

 discovers the diseased part. Recovery and progression may be studied 

 by noting the alteration in time. 



"Owing to the introduction of cerebral surgery and the advances 

 recently made in the treatment of diseases of the nervous system, any 

 method which may make diagnosis more exact deserves careful study. 

 In addition to the time of physiological processes in disease, other tests 

 of loss of sensation, power and intelligence, are made in the labora- 

 tory. The following ten tests are recommended; the methods, etc., 

 are described in an article now in press for Mind: (1) Dynamometer 

 pressure ; (2) rate of movement ; (3) sensation-areas ; (4) i)ressure caus- 

 ing pain ; (5) least noticeable difference in weight; (<>) reaction-time for 

 sound ; (7) time for naming colors ; (8) bisection of 50 centimeters line; 

 (9) judgment of 10 seconds time; (10) number of letters remembered 

 on hearing once. These determinations are made not only on those 

 who are suffering from disease, but also on every one who wishes to 

 be tested. It is hoped that the same tests will be made elsewhere, so 

 that the results of a large number of observations may be compared 

 and combined. The undergraduate students in experimental psycol- 

 ogy undertakes a course of laboratory work in which about two hun- 

 dred tests and measurements are made. It is hoped that when a sutfi- 

 cient mass cf data has been secured, it will have some scientific value. 

 In the cases of two of the tests given above, the rate of movement 

 and the pressure causing pain, researches are being carried out in the 

 laboratory. By altering the distance and nature of the movement, and 

 the point of the l>ody to which the pressure causing i)ain is applied, 

 new quantitative results are obtained." 



Professor Fullerton is carrying on a research to determine the rate 



