126 THE ACQUISITION OF SKILL IN ARCHERY. 



DIRECT EFFECTS OF FATIGUE. 



Fatigue may have an effect upon the rate of learning in other ways than by 

 changing the intensity of the primary stimulus. 



A. Neurone Patteuns. 



It is probable that in order to obtain a given result different groups of neu- 

 rones must be employed when the organism is fresh from those employed 

 when it is fatigued. Thus, subjects in the 40- and 60-shot groups were seen to 

 adopt different attitudes in aiming as they grew tired. The result of this is 

 that a greater number of coordinations must be made to produce the same 

 degree of skill whenever practice involves much fatigue. 



B. Muscle Changes. 



In archery there is a po.ssibility that the effect of the distribution of practice 

 is a function of muscle growth under different conditions of exercise. There 

 seem to be no adequate studies on this subject. 



PRACTICE BETWEEN PRACTICE PERIODS. 



Where the subjects arc interested in the experiment it is impossible to 

 prevent their thinking and talking about it during the intervals between 

 practice periods. This is the suggestion made by Thorndike in respect to 

 Munn's results for language habits in substitution tests. It seems to apply 

 equally well for the early stages of habits of manipulation in man (see p. 122), 

 but its application to the rat in the maze test is questionable. 



FIXATION OF THE NEURAL ARC. 



Starch's first suggestion quoted above imjjlies that a single activation of a 

 neural arc starts up a process of fixation which continues for some time and 

 that the further functioning of this arc during the process of fixation does not 

 accelerate the process of fixation proportionately. By way of illustration, the 

 following analogy may serve: Each time that a door with rusty spring hinges 

 is opened it swings more easily. But when one man has opened the door others 

 may follow him before it swings shut without wearing the hinges smooth. It 

 is only when some time intervenes between the passage of the men that each 

 reduces the friction in the hinge equally. 



THE TIME RELATION OF PRACTICE TO THE CHANGES IN THE PRIMARY STIMULUS 

 RESULTING FROM SUCCESSFUL ACTIVITIES. 



The conception that the fixation of a habit is the con.sequence of its pleasur- 

 able result has been stated in a somewhat objective form by Ladd and Wood- 

 worth in a discussion of the escape of the animal from the problem box. as 

 follows : 



We must assume in the animal an adjustment or determination of the psycho-physical 

 mechanism toward a certain end. The animal desires, as we like to say, to get out and to 

 reach the food. Whatever be his consciousness, his behavior shows that he is, as an organ- 

 ism, set in that direction. The adjustment persists till the motor reaction is consummated; 

 it is the driving force in the imremitting efforts of the animal to attain the desired end. 

 His reactions are, therefore, the joint result of the adjustment and of stimuli from various 

 features of the cage. Each single reaction tends to become associated with the adjustment. 

 But the unsuccessful reactions are less strongly associated than the successful, because each 

 one of the former is at some moment given up or inhibited; and this inhibition, too, being 



