Some Aspects of Attention 321 



stimulus may be fully discriminated. The rabbit or wild 

 bird crouching motionless close to the ground, watching 

 each movement of a possible enemy, suggests strongly to 

 our minds a condition of breathless attention. Whether 

 such an interpretation is the true one depends very much, 

 I should say, on the extent to which past individual expe- 

 rience has refined the animal's powers of discrimination. 

 Mere " freezing to the spot" may be an inherited reaction, 

 useful in time of danger, but more analogous in its psychic 

 aspect to the blank emptiness of the hypnotic trance than 

 to alert, watchful attention. 



Yet although, in so far as attention is a state favoring 

 discrimination of stimuli, it is involved in that part of an 

 animal's behavior which is derived from individual expe- 

 rience, since pure instinct discriminates but roughly ; in so 

 far as it is still one of the devices for securing reaction to 

 stimuli of vital importance, its root must lie in instinct. No 

 object wholly unrelated to some fundamental instinct can 

 hope to secure attention, for the great classes of vitally 

 important stimuli have all of them preformed paths in the 

 nervous system by which their reactions are secured. What 

 individual experience does is to refine upon the adaptations 

 which instinct makes possible ; to bring about the connec- 

 tion of certain stimuli, originally indifferent, with the per- 

 formance of an instinctive response, or to produce a check- 

 ing of the instinctive response when certain individual 

 peculiarities of a stimulus that would otherwise call it 

 forth become evident. For instance, an animal learns by 

 experience to come at the call of a human being who feeds 

 it ; the sound, originally without effect on its reactions, has 

 come to be connected with the nervous mechanism of an 

 instinct. The chick pecking at small objects on the ground 

 learns by experience to inhibit this instinctive response with 



