Retrieving object color: the influence of color congruity and test format.

Incongruous episodes, relative to congruous episodes, engender better memory, but it is unclear whether recollection or familiarity is responsible. Hence, objects were encoded in either natural (yellow banana) or unnatural (blue banana) outline colors. Event-related potentials were recorded while memory was assessed by item (IT) and source (ST) tasks. During IT, unnatural color relative to natural color objects produced better memory and more positive parietal activity (500-600 ms) indicative of recollection. Surprisingly, the converse occurred in ST. As the encoding task required a natural/unnatural decision, an unnatural color object would have required activation of its natural counterpart to make an informed decision. Thus, source confusion during ST relative to IT would have led to a recollection disadvantage for unnatural color objects.