666 o. 1). ANDERSON 



TABLE 8 

 Bog 814(3 



1 MONTH 



AFTER EXTBAC 



WITHDRAWN 



Correct responses to positive Met. 120 82% 82% 70% 



Correct responses to negative Met. 28 s 60% 71% 66% 

 Average magnitude of C-R to 



positive Met. L20 13 t 14 16 



: A correct response to a negative conditioned stimulus was counted as 

 only when there was no response at all. 

 t Hundredths cubic centimeter of saliva. 



Dog 868 i , bassethound X shepherd F 2 . The motor C-R was 

 used and the stimuli for this were Met. 120 (positive) and 

 Met. 28 (negative). The dog- was trained for 14 months be- 

 fore this experiment. 



This animal exhibited a well-balanced behavior and was 

 alert, playful, energetic, quite friendly with people, somewhat 

 aggressive with dogs, and showed little evidence of shyness. 

 When brought to the laboratory he always trotted into the 

 room ahead of the experimenter, and when placed in the loose 

 straps on the platform would, when not being stimulated, sit 

 quite still for periods often exceeding 1 hour in length. He 

 sometimes fell asleep on the experimental platform. This 

 calm behavior is remarkable in view of the fact that an 

 electric shock was applied during the experiments. 



The defensive C-R was developed in the animal in eleven 

 combinations of Met. 120 and shock. The response was there- 

 after highly efficient. 



The dog was fed thyroid extract, 1 gm. daily for 39 days, 

 and the C-R and the general behavior were definitely affected 

 by the treatment. The magnitude of the response was aug- 

 mented, and the animal became at this time quite nervous and 

 restless. The efficiency of the C-R was, however, not materially 

 altered. The effects tended to disappear on withdrawal of 

 the extract. 



As can be seen from table 9, the percentage of correct 

 responses to Met. 120 was not materially affected during 



