The effect of high risk for depression on memory

Abstract

Not everything is remembered equally well. Emotionally arousing information is generally better remembered than non-arousing information. Also, the presence of prior knowledge, or 'schema', facilitates memory for new information that is congruent with such schema. lt has recently been shown for emotionally neutra! information that this schema-related memory facilitation is mediated by the media! prefrontal cortex (mPFC) and is less dependent on the hippocampus. Jndividuals at risk for or with a depressive disorder tend to remember negative information better than neutra! or positive information. Using event-related fMRI, we investigated whether this negative memory bias in people at risk for depression, defined by a high neuroticism (N) score, can be explained by a schema for sad information. Brain activity was measured in low-N and high-N individuals during incidental encoding of happy, sad, and negative-arousing pictures. Cued recall was assessed the next day outside the scanner to model brain activity during successful encoding. We hypothesized better memory for negative­arousing pictures independent of group and for sad pictures in the high-N group relative to the low-N group. As predicted, all subjects showed better memory for negative-arousing pictures. We found no differences between the groups in memory performance in any of the conditions, or in hippocampal or mPFC activity during successful encoding of happy or sad pictures. For subsequently remembered negative-arousing pictures, we found that low-N subjects showed more activity than the high-N subjects in the media! tempora! lobe, the amygdala and mPFC. This study provides a fruitful starting point to investigate the potential role of mental schemas on memory biases in depressed patients.