The relationship between cortical electrical activity and discrimination learning in the cat

A detailed, analysis of five band widths in the EEG of the cat was carried on the motor, visual and auditory cortices during a two-stage visual discrimination learning situation. The band widths had central frequencies of 20.0, 25.0, 31.5, 40.0, and 50.0 cps. Continuous EEG records were taken during acquisition of the simple and complex learning situation. These were simultaneously recorded on tape and computer analyzed. The analysis yielded summary averages for the 10 second pre-stimulus, stimulus, and post-stimulus periods of the central frequencies of 20.0, 25.0, 31.5, 40.0, and 50.0 for the auditory, motor, and visual cortices. The analysis also broke the trials into one of four conditions: 1-trial was a SD with a response made; 2-trial was a SD with no response made; 3-trial was a S∆ with response made; and 4—trial was a S∆ with no response made. The results of the complete analysis were as follows: 1. The motor and auditory cortices showed no significant relationships during this learning situation. No significant differences existed between the pre-stimulus and stimulus periods in any frequency for either cortex under any of the four conditions. 2. The visual cortex analysis showed an significant inverse relationship between the 20 cps activity and 31.5, 40.0, and 50.0 cps bands under condition one; 20 cps consistently decreased during the stimulus period from its pre-stimulus level, as the three higher bands increased. 3. Under conditions two, three, and four, in the visual cortex results varied with little significance. Condition two can only contribute doubtful conclusions because it is represented by very small sample sizes that may well be biased. Conditions three and four fail to show significant changes in the five frequencies. It was concluded that some form of inverse relationship exists between the 20 cps activity and the 31.5, 40.0, and 50.0 cps band, the cause of which will necessitate further research in this area.