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ROBERT P. ERICKSON 



patterns of response for a number of taste solutions must be observed. 

 Second, it must be determined if these patterns are actually significant 

 for the interpretation of the quahties of the taste stimuh. In the experi- 

 ments which follow, neural patterns were determined for several taste 

 substances ; predictions concerning the discriminability of these taste 

 solutions were then made from their neural patterns and tested in 

 behavioral experiments. 



DETERMINATION OF SIGNIFICANT ASPECT OF 

 AFFERENT MESSAGE; PHYSIOLOGICAL AND BEHAVIORAL 



First, the responsiveness of a number of chorda tympani fibers to 

 several taste solutions was determined in the rat anesthetized with pento- 

 barbital sodium. Some of these data are presented in Fig. 4 in a way 



60 



40- 



30- 



20- 



bj 10- 



• • 0.3M KCI 



O O IM NoCI 



'\ 



CHORDA TYMPANI FIBERS (RAT) 



Fig. 4. Across-fiber patterns analogous to those shown in Fig. Ic, except 

 that connected points are used instead of bars, and 13 fibres are shown instead of 

 three. Single rat chorda tympani fibers. Fibers arranged along baseline in 

 order of responsiveness to NH4CI. KCI pattern similar to NH4CI pattern. 

 Neither of these patterns similar to the NaCl pattern. 



which shows the across-fiber pattern. Here the fibers are arranged along 

 the base line in order of their responsiveness to NH4CI. Any other arrange- 

 ment would be satisfactory for the present purposes. The degree of their 

 responsiveness to this solution is indicated by the black dots connected 

 with the solid lines. In this way is shown a pattern of the amount of 

 neural activity across many neural units, and is the across-fiber NH4CI 



