The neural correlates of conceptual and perceptual false recognition.

False recognition, broadly defined as a claim to remember something that was not encountered previously, can arise for multiple reasons. For instance, a distinction can be made between conceptual false recognition (i.e., false alarms resulting from semantic or associative similarities between studied and tested items) and perceptual false recognition (i.e., false alarms resulting from physical similarities between studied and tested items). Although false recognition has been associated with frontal cortex activity, it is unclear whether this frontal activity can be modulated by the precise relationship between studied and falsely remembered items. We used event-related fMRI to examine the neural basis of conceptual compared with perceptual false recognition. Results revealed preferential activity in multiple frontal cortex regions during conceptual false recognition, which likely reflected increased semantic processing during conceptual (but not perceptual) memory errors. These results extend recent reports that different types of false recognition can rely on dissociable neural substrates, and they indicate that the frontal activity that is often observed during false compared with true recognition can be modulated by the relationship between studied and tested items.