Dishabituation occurs when:

Dishabituation occurs when a previously removed stimulus is reintroduced after a period of absence, leading to a renewal of the response to that stimulus. This phenomenon is significant because it highlights how behavioral responses can be modulated by environmental changes.

In classical conditioning, for example, if an organism has been conditioned to respond to a specific stimulus but then shows a diminished response over time (a process known as habituation), the introduction of a new or previous stimulus can reignite that response, demonstrating the flexibility of behavior in relation to stimuli. Dishabituation essentially shows that the initial learning can be temporarily disrupted but is not erased; reintroducing the former stimulus reinstates the original reaction.

This understanding helps illustrate broader psychological concepts related to attention, learning, and memory and the conditions under which behaviors are expressed or suppressed.