Effect of repetitive stimulation on cortical single unit activity.

Activity of single units in the visual and sensomotor cortex of an uncurarized, unanesthetized rabbit was recorded by means of two independent microelectrodes during photic stimulation at different frequencies. Trace effects characterized by repetition of the temporal structure of afferent stimulation and by an increase in the level of intercellular correlation were discovered mainly on analysis of distant interneuronal relations after stimulation with frequencies of 2 and Hz. Stimulation at a frequency of 8 Hz did not evoke trace effects.