272 Information Storage and Neural Control 



TABLE II 



Generalization of Differentiated Avoidance Response to Central 



Stimulation of Other Electrode Placements Following Establishment of 



Differential Response to Electrical Stimulation of 



Left vs. Right Visual Cortex 



mediating the differential performance to the central stimulation, 

 this relationship has been preferentially established to only one 

 of the two stimulated regions. This finding is consonant with 

 the analogous report of Loucks (15), but extends his observation 

 to differentiated responses. 



It is also of interest that bipolar subcortical stimulation, without 

 reinforcement, did not elicit generalization of performance. In 

 subsequent training, we obtained some indication of performance 

 of conditioned responses to stimulation of the reticular formation in 

 this animal. A total of 175 conditioned responses were obtained in 

 460 trials. Performance fluctuated between 70 per cent and per 

 cent and did not stabilize. This may indicate changes in neural 

 threshold since all trials were conducted in the same current range, 

 or may reflect artifact due to an increase of operant level which took 

 place. Systematic studies of generalization and transfer of differ- 

 ential conditioned response from one site of central stimulation to 

 another, in conjunction with electrophysiological studies, may help 

 elucidate the neuial mechanisms mediating such perfoimance. 



DIFFERENTIAL EFFECTS OF LATENCY ON 

 DISRUPTION DURING CONCURRENT STIMULATION 



Some months after the preceding experiments were concluded, a 

 final study was carried out on Cat 4. Under extinction conditions, it 

 was observed that stimulation of visual cortex at previously effective 

 parameters no longer elicited the conditioned response. No attempt 

 was made to ascertain whether the introduction of reinforcement 



