526 PSYCHOLOGY. 



that for distingiiisliing a given letter from all the rest of 

 the alphabet (not reacting until that letter appeared) 



0.119 and 0.116 ; 



that for distinguishing a word from any of twenty-five other 

 words, from 



0.118 sec. to 0.158 sec. 



The difference depending on the length of the w^ords and 

 the familiarity of the language to which they belonged. 



Prof. Cattell calls attention to the fact that the time for 

 distinguishing a word is often but little more than that for 

 distinguishing a letter : 



"We do not. therefore, distinguish separately the letters of which 

 a word is composed, but the word as a whole. The application of this in 

 teaching children to read is evident." 



He also finds a great difi'erence in the time with which 

 various letters are distinguished, E being particularly 

 bad.* 



I have, in describing these experiments, followed the ex- 

 ample of previous writers and spoken as if the process by 

 which the nature of the signal determines the reaction w^ere 

 identical with the ordinary conscious process of discrimina- 

 tive perception and volition. I am convinced, however, 

 that this is not the case ; and that although the results are the 

 same, the form of consciousness is quite difierent. The reader 

 will remember my contention (supra, p. 90 fi".) that the simple 

 reaction-time (usually supposed to include a conscious pro- 

 cess of perceiving) really measures nothing but a reflex 

 act. Anyone who Avill perform reactions with discrimina- 

 tion will easily convince himself that the process here also 

 is far more like a reflex, than like a deliberate, operation. I 

 have made, wuth myself and students, a large number of 

 measurements where the signal expected Avas in one series 

 a touch somewhere on the skin of the back and head, and 

 in another series a spark somewhere in the field of view. 

 The hand had to move as quickly as possible towards the 



* For otlier determinations of discrimination-time by this method cf. 

 V. Kries and Auerbacb. Arcbiv f. Physiologic, Bd. i p. 297 ff. (these au- 

 thors get much smaller figures); Fricdrich, Psycbologische Studien, i. 39. 

 Chapter ix of Buccola's book, Le Legge del tempo, etc., gives a full ac- 

 count of the subject. 



