Figure 5. Summary of conditioning effects on antidromic cortical field potentials.

A, size of antidromic field (percentage of the unconditioned amplitude, as a function of interstimulus interval), averaged across datasets. PT and spinal cord conditioning stimuli produced marked facilitation of the antidromic response for interstimulus intervals up to 40 ms. No facilitation was seen following conditioning stimuli delivered to the peripheral nerves. B, percentage occurrence of facilitation effects which were individually significant at the P < 0.05 level. (PT, 11 datasets; spinal, 7 datasets; nerve, 20 datasets).