Opposing patterns of neural priming in same-exemplar vs. different-exemplar repetition predict subsequent memory

摘要

The present neuroimaging study examines how repetition-related neural attenuation effects differ as a function of the perceptual similarity of the repetition and subsequent memory. One previous study () reported greater attenuation effects for subsequent hits than for misses. Another study () found that neural attenuation is negatively correlated with subsequent memory. These opposing results suggest that repetition-related neural attenuation for subsequent hits and misses may be driven by different factors. In order to investigate the factors that influence the degree of neural attenuation, we varied perceptual similarity between repetitions in a scanned encoding phase that was followed by a subsequent memory test outside the scanner. We demonstrated, in a novel result, that the degree of neural attenuation in the object processing regions depends on the interaction between perceptual similarity across repeated presentations and the quality of the encodings. More specifically, the same areas that decreased neural signal for repetitions of same-exemplars that were subsequently recognized with confidence that the repetitions were identical, but not misses, showed a decrease in neural signals for different-exemplar misses but not for the corresponding subsequently recognized hits that included confidence that the repetitions were different. Our results imply that repetition-related neural attenuation should be related to the more efficient processing of perceptual properties of the stimuli only if subjects are able to subsequently remember the stimuli. Otherwise, the cause of attenuation may be in the failure to encode the stimuli on the second presentation as shown by the pattern of neural attenuation for the different-exemplar misses in our study.