Neural Mechanisms of Decision Making 259 



sort described. Yet some insight may be offered from the fact that 

 only visual cortex and reticular formation, among the structures 

 studied in this animal, displayed these peculiar waveforms during 

 generalization. Lateral geniculate was notably regular in its 

 response. This configuration suggests that somehow an interaction 

 between visual cortex and reticular formation may be central in 

 the mediation of phenomena of this sort. Further work is obviously 

 necessary before the interpretations offered here can be accepted 

 as accurate. 



CHARACTERISTICS OF MISTAKES 

 DURING DIFFERENTIATION 



Although the data presented in the preceding section are of a 

 different sort from those which Killam and I described previously, 

 they are in accordance with observations we made while studying 

 the difference in electrical recordings obtained during correct and 

 erroneous performance of flicker discriminations in a differential 

 approach-avoidance situation (9). In those animals, we observed 

 that among the most marked changes in labeled potentials during 

 differential conditioning were those which occurred in the reticular 

 formation, intralaminar nuclei, and hippocampus. A particular 

 relationship between the configuration of potentials in these struc- 

 tures and in visual cortex seemed to be closely related to appropriate 

 performance. During signal presentation, potentials in the non- 

 specific structures could often be observed at either of the two 

 flicker frequencies between which differential response had been 

 established. Wlien behavioral performance was appropriate to the 

 peripheral OS, the frequencies of potentials in visual cortex and 

 in nonspecific regions were in good correspondence to the OS. 

 However, when behavioral performance was inappropriate, the cor- 

 respondence of labeled potentials to tlie CIS diininished and periods 

 of hypersynchrony appeared at the frequency of the stimulus 

 appropriate to the behavior actually performed, particularly 

 in centralis lateralis, dorsal hippocampus and reticular forma- 

 tion. In Figure 10 are presented recordings obtained from a cat 

 trained to perform a lever press to obtain milk during a ten per 

 second flicker without reinforceinent during six per second flicker. 



