1908.] 



OF SUBLIMINALLY COLORED STIMULI. 



371 



The regular observers were T, P, G, and Mr. T. Nakashima, gradu- 

 ate scholar in psychology (N). A few observations were secured 

 from Professor I. M. Bentley (B), and from an unpractised ob- 

 server, Mr. H. J. Bool; single observations w^ere made by several 

 visitors to the laboratory. 



In intention, the procedure was without knowledge. In practice, 

 the experimenter found it impossible, in the early stages of the 

 work, to regulate the size of the colored sector in precise accordance 

 with the course of adaptation. The observer was therefore in- 

 structed to tap on the table with a pencil whenever he perceived 

 a color in the stimulus. If a tap was given, the experimenter ran 

 the colored sector back through five or ten degrees, and continued 

 the experiment from that point. The results of these interrupted 

 observations varied, according to the frequency of the taps and the 

 insistence of the color in the stimulus. The following are typical 

 records. 



After a period for recovery, the stimuli were exposed at their 

 final color-strengtl/for 30 sec, and the after-image was projected 

 as before. The results, in the above instances, were as follows : 



