What results when a dog becomes reactive to all sudden loud noises after being repeatedly exposed to a gun firing?

When a dog becomes reactive to all sudden loud noises after being repeatedly exposed to a gun firing, this is a clear example of sensitization. Sensitization occurs when repeated exposure to a stimulus, in this case, the loud noise from a gun, leads to an increased response to that stimulus or to other stimuli that are similar or associated with it. Instead of the dog becoming accustomed to the noise and responding less over time, as it might with habituation, the dog's reaction intensifies.

This heightened sensitivity can lead to a more generalized reactivity to other loud noises, as the initial experience with the gun firing has set off a heightened state of alertness or anxiety regarding loud sounds. It’s important to note that while habituation would typically imply a decline in response due to familiarity, sensitization reflects an opposite effect, where the animal becomes more reactive as a result of previous experiences.

In contrast, adaptation refers to a physiological adjustment to a constant stimulus, learned irrelevance suggests that the dog does not associate the noise with anything significant, and habituation would mean the dog becomes less responsive, which is not the scenario described.