Changes in the intensity of repeated, ignored sounds elicit the mismatch negativity (MMN) brain response which reflects preattentive detection of the change. It is generally assumed that the MMN in response to intensity changes reflects a memory-based comparison mechanism rather than being due to differential states of refractoriness of intensity-specific cortical neurons. In the present study, an experimental protocol consisting of 4 oddball blocks and 1 control block was used in order to separate memory-comparison-related effects from refractoriness-related ones. This design allowed an assessment of intensity MMN using physically identical stimuli with equal probability of occurrence in separate blocks, while avoiding contamination by refractoriness. Results were consistent with an MMN in response to intensity change that reflects genuine memory-based comparison.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.