"Counting" of clicks, as reflected in amplitude of potentials evoked in auditory cortex of the dog.

In eight dogs with chronically implanted electrodes click-evoked potentials were recorded in the ectosylvian and suprasylvian gyri. During daily sessions clicks were presented in several short trains with a steady interclick interval of 1 s and not followed by any unconditional stimulus. The largest amplitudes resulted from the first and last clicks in the series so that curves plotted for each series assumed a U-shape. Changing the intensity or interclick interval disrupted this pattern.