404 



BRAIN MECHANISMS AND LEARNING 



permanently implanted in the parotid duct. The light was turned on 4 

 seconds before presenting the food to the animal. A typical conditioned 

 pattern of behaviour was established after ten to fifteen trials (Fig. 7). As 

 soon as the light was turned on, the cat showed an orienting reaction 

 directed towards the opening through which the food was delivered. Then 

 the cat stared and approached the food-clamp upon its presentation. Very 

 often, the cat tried to catch the food by rising on its hindlegs. During the 

 presentation of the conditional visual stimuli, one or two drops of saliva 

 flowed thrt)ugh the parotid catheter. 



CoiuHtioiicd flexor rc<:poiisc in intact cats. Aiter the establishment of ali- 

 mentary conditioned responses, the cats were conditioned to acoustic and 



CONDITIONING VISUAL STIMULI 



LIGHT and FOOD-HOLDER 



Fk;. 7 

 This figure illustrates the sequential behavioural response of a cat conditioned with visual 

 stimuli (light and food-holder) and food. When the light was turned on, the cat oriented its 

 head towards the lamp and when seeing the food-holder it rose on its feet and tried to catch 

 the food. 



nociceptive stimuli according to the following procedure: the animal was 

 immobilized in a harness to which its legs were fastened. A buzzer was 

 rung fc~>r 5 seconds and then a shock was delivered from a Grass Stimulator 

 through electrodes attached to the left foreleg of the animal. The shock 

 evoked a definite flexion of the limb and generalized struggling move- 

 ments. The contraction of the flexor muscles of the left foreleg was 

 recorded with bipolar intramuscular electrodes and an electromyograph. 

 After six to ten buzzer-shock associations, the buzzer alone elicited the 

 flexion of the limb and the struggling reaction. 



Cofiditio}icd alimentary responses in decorticate cats. Salivation and the 

 expectant attitude were easily conditioned to the light and to the fish 

 odour in cats from which the neocortex had been bilaterally removed 2 to 



