Has the butcher on the bus dyed his hair? When color changes modulate ERP correlates of familiarity and recollection.

Recognition memory is usually thought of as comprising two distinct memory processes, namely familiarity and recollection. This distinction is reflected in specific event-related potential (ERP) components associated with both subprocesses. A mid-frontal attenuated negativity for correctly recognized old items relative to new ones around 400 ms has been typically linked to familiarity, whereas a parietally accentuated, more pronounced positivity for old items from 500 to 800 ms has been connected with recollection. Recently, this classification has been challenged by relating the mid-frontal old/new effect to conceptual priming mechanisms. Moreover, the perceptual sensitivity of both old/new effects is still under debate. The present study used a recognition memory task for visual objects and nonsense figures in order to investigate the functional significance of both ERP old/new effects. With respect to study presentation, all items were either presented in a perceptually identical or a color-modified version at test. Old nonsense figures, despite being meaningless, elicited a reliable mid-frontal old/new effect, thereby strongly suggesting a close relationship to familiarity processes rather than conceptual priming. Additionally, both the mid-frontal and the parietal old/new effect for real objects were graded with respect to the perceptual similarity between study and test. We argue that not only recollection, but also familiarity processes can provide information about perceptual atttributes, which is used in the course of recognition memory decisions.