Discriminated lateralized eyeblink conditioning in the rabbit: an experimental context for separating specific and...

Four experiments are reported that demonstrate discriminated lateralized eyeblink conditioning in rabbits and show how the phenomenon may be used to differentiate between the reflexive and emotive consequences of Pavlovian conditioning. Experiments 1, 2, and 3 characterized how 2 conditioned stimuli (CSs), contemporaneously trained with left vs. right paraorbital unconditioned stimuli (USs), can produce different conditioned reflexes (CRs), each involving predominant closure of the eye ipsilateral to its US. Experiment 4 showed how the associative tendencies controlled by additional stimuli could be evaluated by presentations in compound with such discriminanda: A 30-s stimulus, presumed to acquire a conditioned emotional response but no eyeblink CR, equally potentiated the eyelid CRs elicited by both CSs; a 1,050-ms CS that evoked an eyeblink CR in isolation also increased the responding to both CSs but biased it toward its own lateralized CR.