Figure 4.

A weak-strong electrical shock of the supraorbitary branch of the trigeminal nerve, with a trace paradigm, was used for classical conditioning of eyelid responses. A, Differential progress in the percentage of CRs per session across conditioning between conditioned (Cond.; filled circles) and pseudoconditioned (Pseudo.; open circles) groups (n = 8 per group). B, C, Representative single-trial records of the EMG of the OOM during different training sessions obtained from one subject of the conditioned (B) and pseudoconditioned (C) groups. H, Habituation; C1-C8, first through eighth conditioning sessions; PC8, eighth pseudoconditioning session.