The relationship between study processing and the effects of cue congruency at retrieval: fMRI support for transfer appropriate processing

Using functional magnetic resonance imaging, the present study investigated whether the enhanced memory performance associated with congruent relative to incongruent retrieval cues is modulated by how items are encoded. Subjects studied a list of visually presented words and pictures and attempted to recognize these items in a later memory test. Half of the studied items were tested with a congruent cue (word-word and picture-picture), whereas the remainders were tested with an incongruent cue (word-picture and picture-word). For both words and pictures, regions where study activity was greater for congruently than incongruently cued items overlapped regions where activity differentiated the 2 classes of study material. Thus, word congruency effects overlapped regions where activity elicited by study words exceeded the activity elicited by pictures. Similarly, picture congruency effects overlapped regions demonstrating enhanced activity for pictures relative to words. In addition, several regions, including dorsolateral prefrontal cortex and intraparietal sulcus, demonstrated material-nonspecific congruency effects. The findings suggest that items benefit from a congruent retrieval cue when their study processing resembles the processing later engaged by the retrieval cue. Consistent with the principle of transfer appropriate processing, the benefit of a congruent retrieval cue derives from the interaction between study and retrieval processing.