77?^' Individual as an Information Processing System 



319 



INPUT RATE (BITS/SEC) 

 Fig. 5. Average utilization of adjustment processes by both subjects at various 



input rates. 



able, however, that uhimately, at very high input rates, output 

 does falL The maximum channel capacity for an individual 

 operating the IOTA was determined to be about six bits per 

 second. Other experimenters have found maximum channel 

 capacities for random material up to about thirty bits per second. 

 With the IOTA, however, output rate is limited by partial in- 

 compatibility between the nature of the stimulus and the organiza- 

 tion of the response mechanism, by the difficulty of making the 

 response, and by many other factors. 



Our subjects were trained regarding the possible mechanisms 

 of adjustment available to them, and were free to select them as 

 they saw fit. They used few or none of the mechanisms at slow 

 rates of transmission. They tended to attempt them all at medium 

 rates. At higher rates, under our experimental conditions, the 

 subjects showed preference for filtering and, particularly, for 

 omission (Fig. 5). Whether this preference is genetically deter- 

 mined or learned, we do not know. 



