PROBLEM 227 



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teacher note the number of seconds for the word to get back to 

 the starting point. By dividing this time by the total number of 

 participants the average reaction time for hearing of the class can 

 be obtained. 



Now let members of the class just touch finger tips. In the same 

 manner as in the previous experiment, let the instructor start a 

 signal (a short pressure of the fingers). Get the average reaction 

 time as in the previous experiment. 



Conclusion. — Which gives a quicker reaction, hearing or touch ? 



Problem 226: To compare a reflex action, with an act of 

 thought. 



Method. — Using the figures note the pathway with relays 

 of cells between the 

 eye when you see a 

 book, and the rest 

 of the nerves in- 

 volved when you de- 

 termine to pick it up 

 and do so. 



Observations. — 

 Make a diagram 

 showing the path- 

 way. Compare this 

 pathway with the 

 one taken when you touch your hand against a hot stove in the 

 dark. 



Conclusion. — What is the chief difference in the nervous path- 

 way between a reflex and an act of thought ? 



Problem 227 : To study habit forming. 



Note. — A little chick just hatched in an incubator picks at food. It has no 

 mother to teach it. Such an act is called instinctive. It is an act accomplished 

 without reasoning. When a new-born baby sucks, its act is also instinctive. 

 Upon such instincts life depends. 



Observations. — • When a baby is just learning to walk, the first 

 step would probably be brought about by its reaching or stretch- 



An iNVOLtTNTAKT AcT. 



