R. W. DOTY AND C. GIURGEA 1 37 



Dog Beta. A us of 2.0 niA. at the right postcruciatc gyrus produced a 

 brisk, well-integrated flexion of the left hind leg as its only apparent 

 effect. The CS at the right marginal gyrus gave no overt sign at intensities 

 up to 2.2 mA. The hrst sign of movement to this CS occurred during the 

 sixth session, forty-fifth pairing. The slight tossing of the head and 

 indefniite movements such as stepping or shifting posture seen then sub- 

 sequently became very common. On the sixty-sixth piairing two lo-cm. 

 flexions of the left hind leg, held for about i second each, were seen as the 

 only movement to the CS. This was the first CR. This type of CR occurred 

 seventy-four times in 171 subsequent CS presentations (including extinc- 

 tion) and had a threshold of 0.95 mA. It was not extinguished by eighty- 

 four presentations of the CS alone at 2-3 minute intervals for eleven 

 sessions. These CRs were also obtained to stimulation ofthe right posterior 

 cctosylvian gyrus indicating some generalization had occurred. 



Technical difficulties prevented testing this dog in the lever-pressing 

 situation. However, the animal was extraordinarily sensitive and yelped 

 violently even when grasped gently by the scruff" of the neck. Yet there 

 was no evidence of pain or emotion during the training sessions, and the 

 animal ran each day to the experimental room and jumped into the 

 enclosure to be harnessed. 



Dog Gallium. Stimulation at 0.4 mA. 1.5 mm. above the right pyramid 

 in the field H^ of Forel was used as US. It produced a forceful extension of 

 the neck and rotation ofthe head over the right shoulder, wider opening 

 ofthe eyes, flaring ofthe nostrils and occasionally a lilting ot the right lip 

 (Fig. 2). This response was elicited sixty-eight times in ten sessions with no 

 particular alteration in the animal's behaviour. Pairing ofthe US with a 

 CS of 3/second clicks was then begun. A CR of turning the head up and 

 130° right was elicited by the CS on the sixteenth trial and similar CRs 

 occurred on forty-eight of ninety-six subsequent presentations. The CS 

 also evoked great agitation, whining and yelping. Both the CRs and this 

 agitation to the CS were extinguished in three sessions totalling twenty- 

 two presentations of the CS alone. 



Lever-pressing behaviour was little altered by coupling with stimulation 

 ofthe postcruciate gyrus producing a hind-leg left. It was slowed greatly 

 by the click CS or other sounds, and abolished immediately by the US. 



Dog Epsiloii. Stimulation at right or left postcruciate gyri produced well 

 co-ordinated, maximal flexions of left or right forelegs respectively. 

 Stimulation of left posterior ectosylvian gyrus with 1.8 mA. or right mid- 

 marginal gyrus with 1.6 mA. produced no response when tested initially. 

 Stimulation at the latter points was then used as CS and at the former as 



