What concept explains the disregard of a new stimulus presented alongside a pre-existing salient stimulus?

The concept that explains the disregard of a new stimulus presented alongside a pre-existing salient stimulus is known as blocking. This phenomenon occurs when a previously conditioned stimulus (the salient stimulus) overshadows the conditioning process of a new stimulus. In other words, if an animal has already learned to associate a certain stimulus with a particular outcome or response, introducing a new stimulus that is not distinct enough or does not provide any additional predictive value typically results in the new stimulus failing to evoke a response.

Blocking highlights the importance of the existing knowledge or associations that an animal has, demonstrating that the relevance and predictiveness of stimuli play crucial roles in learning and conditioning. When a strong association has already been established, the animal tends to focus on the already salient stimulus and may ignore additional stimuli that do not contribute additional or useful information to the established association. This feature of learning emphasizes the selectiveness and efficiency of the learning process in animals, allowing them to prioritize stimuli based on their relevance and salience in their environments.