The interstimulus interval and classical conditioning in the marine snail Hermissenda crassicornis
1Laboratory of Molecular and Cellular Neurobiology, NIH, Bethesda, MD 20892.
Abstract:
We examined the role of the interstimulus interval for the conditioned association between light and rotation stimuli in the marine snail Hermissenda. This interval between the conditioned stimulus (CS) and the unconditioned stimulus (US) is an important and widespread property of vertebrate associative learning. We demonstrated that with a forward CS-US delay of 1.0 s we were able to produce significant 24-h retention of an associative memory after 50 training trials. Other paired treatments providing intervals of 1.5 s, 0.5 s, simultaneous, and backward arrangements did not support retention at 24 h.
Related Concept Videos
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Classical Conditioning
Ivan Pavlov observed that dogs salivated...
Principles of Classical Conditioning
During the...
Real-World Application of Classical Conditioning
Higher-order, or second-order, conditioning occurs when a neutral stimulus becomes associated with an already established conditioned stimulus through repeated pairings. For instance, if a dog has been...
Classical Conditioning in Daily Life
John B. Watson and Rosalie Rayner famously demonstrated the development of fear through classical conditioning in their experiment with Little Albert. They paired the...


