Eyelid conditioning and intellectual level: effects of contextual change on extinction.

A repeated acquisition-extinction paradigm was used to investigate effects of auditory-verbal cues on the ordinarily slow extinction rate of conditioned eyelid responses of mentally retarded adults. Abrupt extinction occurred as a consequence of nearly filling extinction intertrial intervals with either relevant or irrelevant phrases, but the extinction rate was unaffected by a brief phrase in place of the absent unconditioned stimulus. Also, no evidence of transfer was found following reacquisition, when verbal cues were omitted entirely from reextinction. A contextual-change hypothesis, in terms of interference with memory of the unconditioned stimulus, was suggested to account for the data.