Related Experiment Video
Updated: Jul 19, 2026
The Power of Interstimulus Interval for the Assessment of Temporal Processing in Rodents
Published on: April 19, 2019
The ontogeny of interstimulus interval (ISI) discrimination of the conditioned eyeblink response in rats
Kevin L Brown1, Jerome H Pagani, Mark E Stanton
1Department of Psychology, University of Delaware, Newark, DE 19716, USA.
Abstract:
Discrimination of the eyeblink conditioned response (CR) between conditioned stimuli (CSs) of different durations and modalities was examined across development in rats. Interstimulus interval (ISI) discrimination was evident at Postnatal Days 23-34 in Experiment 1, and earlier CR peak latencies and enhanced CR amplitudes were seen to the long CS in the ISI discrimination group relative to a control group receiving the short CS without reinforcement. Experiment 2 showed that early CR peak latencies and enhanced CR amplitudes to the long CS in the ISI discrimination group were due to associative pairing of the short CS and unconditioned stimulus. Experiment 3 demonstrated ISI discrimination in adults that was improved relative to younger subjects, but with no enhancement of CR amplitude to the long CS in the ISI discrimination group. Cerebellar cortical maturation may influence the ontogeny of CR timing.
