The nature of memory failure in mild cognitive impairment: examining association with neurobiological markers and effect of progression.

The main goal of this study was to assess vulnerability to proactive interference and memory binding capacity, the ability to combine different information into a single coherent memory event, in persons with mild cognitive impairment (MCI). We also examined whether hippocampal atrophy and vascular burden were differentially related to these memory capacities in MCI. We further assessed whether memory performance and brain changes differ as a function of later development (or not) of dementia and whether they can predict progression to dementia. The study included 77 participants, 49 meeting the criteria for MCI and 28 healthy older adults. Results showed binding deficits and greater vulnerability to proactive interference in persons with MCI compared with healthy older adults. Hippocampal volume was associated with binding capacity, whereas vascular burden was associated with resistance to interference in persons with MCI. Follow-up analyses indicated that binding deficits predict progression from MCI to dementia. In conclusion, binding deficits and vulnerability to proactive interference are present in persons with MCI and are associated with different brain markers. However, only binding deficits predict progression to dementia.