Blocking occurs when a second CS is added, after conditioning to a first CS has already been completed.

Question

Quizplus · Accepted Answer

Blocking occurs when a conditioned stimulus (CS) that has already been associated with an unconditioned stimulus (US) to produce a conditioned response (CR) prevents a new CS from being associated with the US. This happens because the first CS already predicts the US, so the second CS does not add any new information or predictive value.

Blocking Occurs When a Second CS Is Added, After Conditioning