Memory Retrieval Effects as a Function of Differences in Phenomenal Experience
Conscious experience and perception are restricted to a single perspective. There is evidence to suggest differences in phenomenal experience can produce observable differences in behavior, however it is not well understood how these differences might influence memory. We used fMRI to scan n=49 participants while they encoded and performed a recognition memory test for faces and words. We calculated a cognitive bias score reflecting individual participants propensity toward either Visual Imagery or Internal Verbalization based on their responses to the Internal Representations Questionnaire (IRQ). We found weak positive correlations between memory performance for faces and a bias toward visual imagery and between memory performance for words and bias toward internal verbalization. There were typical patterns of activation differences between words and faces during both encoding and retrieval. There was no effect of internal representation bias on fMRI activation during encoding. At retrieval, however, a bias toward visualization was positively correlated with memory-related activation for both words and faces in inferior occipital gyri. Further, there was a crossover interaction in a network of brain regions such that visualization bias was associated with greater activation for words and verbalization bias was associated with greater activation for faces, consistent with increased effort for non-preferred stimulus retrieval. These findings suggest that individual differences in cognitive representations affect neural activation across different types of stimuli, potentially affecting memory retrieval performance.