What term describes the gradual loss of response to a stimulus?

The correct term for the gradual loss of response to a stimulus is desensitization. This phenomenon occurs when an individual becomes less responsive to a stimulus after repeated exposure to it. In sensory terms, desensitization can be observed in various contexts, such as taste or smell, where the initial intensity of the response diminishes over time as the stimulus is continuously presented. This process is important in understanding how sensory systems adapt to constant stimuli, allowing organisms to focus on novel or more significant changes in their environment.

The other terms mentioned have different meanings or contexts. Calibrative fatigue typically refers to a decrease in the sensitivity of a system or instrument over time but not specifically related to the gradual loss of response to sensory stimuli. Progressive habituation involves the broader concept of getting used to a stimulus, but doesn't directly define the specific mechanism of losing responsiveness. Response decline may imply a reduction in response strength, but it lacks the precise definition and context of desensitization in sensory studies. Desensitization specifically captures the essence of the phenomenon regarding diminishing responses to repeated stimuli.