THE EFFECT UPON THE WHITE EAT OF CON- 

 TINUED BODILY ROTATION 



COLEMAN E. GEIFFITH 

 Psychological Laboratory, University of Illinois 



Everyone knows that a rapid turning-about upon the 

 heels usually leads to dizziness and that a like state is in- 

 duced in the revolving chair or the turn-table of the lab- 

 oratory or in the merry-go-round of street fairs. It is 

 also known, especially among those who have attempted 

 to analyze the complicated experience of dizziness, that 

 an important constituent of this disturbed state of mind 

 and body is a characteristic movement, to-and-fro, of the 

 eyes. To this ocular twitching, which is sometimes called 

 " nystagmus," is due, in large measure, the apparent 

 swimming movement of surrounding objects. The twitch- 

 ing appears soon after rotation begins and it continues, 

 with characteristic modifications, for a short period after 

 the body comes to rest. 



The bodily and mental effects of rotation in man and 

 in other animals have for a good many years been made 

 the subject of investigation by physicists, anatomists, 

 physiologists, psychologists and medical men. It is sup- 

 posed that rotation produces a specific effect upon the 

 neural end-organs of the semicircular canals, and it is 

 definitely known that, in addition, pretty much the entire 

 organism is involved in the general disturbance. Concern- 

 ing the ocular movements themselves, a good deal has 

 been learned. We know, for example, that the character 

 and the duration of the nystagmus depend upon a large 

 and heterogeneous group of conditions, among which may 

 be named the general state of the organism, the state of 

 attention, the associative connections, the rate, regularity 

 and duration of the rotational movements, repetition and 

 practise, and other mental and physical conditions. Of 



