Variation of the intertriai interval in human classical conditioning

The effect of using a short intertriai interval (ITI) in eyeblink classical conditioning in humans was examined. The performance of normal young adults in 750-msec delay conditioning was compared at ITIs of 5, 10, and 30 sec. All groups successfully acquired the task. Performance of each ITI group was similar for pseudoconditioning, conditioning, and extinction trials. Use of shorter ITIs during eyeblink conditioning should reduce test time and possible subject boredom or inattention, thus making the eyeblink conditioning task more useful as part of a neuropsychological test battery for evaluating brain damage and drug effectiveness. Shorter ITIs would also allow eyeblink classical conditioning to be used in concert with other technologies, such as PET scanning, to assess functional activity of the brain during learning.