410 PSyCUOLOOY. 



tAvo signals were simultaneous or successive ; and, if succes- 

 sive, whicli one of tlieni came first. 



The first way of attending whicli he found himself to 

 fall into, was when the signals did not differ greatly — when, 

 e.g., they were similar sounds heard each by a different 

 ear. Here he lay in wait for the Jirst signal, whichever 

 it might be, and identified it the next moment in memor}-. 

 The second, which could then always be known by default, 

 was often not clearly distinguished in itself. When the 

 time was too short, the first could not be isolated from the 

 second at all. 



The second way was to accommodate the attention for a 

 certain sort of signal, and the next moment to become aware 

 in memory of whether it came before or after its mate. 



"This way brings great uncertainty with it. The impression not 

 prepared for comes to us in the memory more weak than the other, 

 obscure as it were, badly fixed in time. We tend to take the subjec- 

 tively stronger stimulus, that which we were intent upon, for the first, 

 just as we are apt to take an objectively stronger stimulus to be the 

 first. Still, it may happen otherwise. In the experiments from touch 

 to sight it often seemed to me as if the impression for which the atten- 

 tion was not prepared were there already when the other came." 



Exner found himself employing this method oftenest 

 when the impressions differed strongly.* 



In such observations (which must not be confounded 

 with those where the two signals were identical and their 

 successiveness known as mere douhJeness, without distinc- 

 tion of which came first), it is obvious that each signal must 

 combine stably in our perception with a different instant of 

 time. It is the simplest jiossible case of two discrepant 

 concepts simultaneously occupying the mind. Now the case 

 of the signals being aimnltaneous seems of a difi"erent sort. 

 We must turn to Wundt for observations fit to cast a nearer 

 light thereon. 



The reader will remember the reaction-time experiments 

 of which we treated in Chapter III. It happened occasion- 

 ally in Wundt's experiments that the reaction-time was 

 reduced to zero or even assumed a negative value, which, 

 being translated into common speech, means that the ob- 



* Pfiilger's Arcbiv, xi. 439-31. 



