Inter-areal differences in the direct cortical response of the middle suprasylvian gyrus of the cat

1. 1. A technique for comparing direct cortical responses (DCRs) evoked under comparable stimulating and recording conditions from various points in the middle suprasylvian gyrus was described. The method appeared to be reliable. 2. 2. Increasing stimulus intensity and varying anesthesia conditions both appeared to affect the amplitude of DCRs in ways which differed from one cortical locus to another. 3. 3. Inter-areal differences in amplitude of the response to a standard stimulus could be demonstrated which were independent of the differences due to other factors.