Training gains and transfer effects after mnemonic strategy training in mild cognitive impairment: A fMRI study

Prior work has revealed that mnemonic strategy training (MST) can enhance memory for specific content and engages regions in the frontoparietal cognitive control network. Evidence of transfer to novel content is less clear. Here, we provide secondary analysis of functional magnetic resonance imaging (fMRI) data acquired during a randomized controlled trial that compared MST to an active education control condition in patients with amnestic mild cognitive impairment (a-MCI). In the trial, thirty participants with a-MCI were randomized to the education program (EP) or MST, where they learned to apply the technique to face-name associations during four intervening hour long training sessions. Participants underwent pre- and post-training fMRI scans, during which they encoded both the trained (i.e., those used during the four training sessions) and untrained (`novel') face-name associations. The primary cognitive outcome measures revealed significantly improved memory for both trained and novel stimuli - effects supporting near transfer of MST. Relative to pre-training, there were significant and highly similar increases in activation for both trained and novel stimuli, especially in regions associated with the frontoparietal cognitive control network bilaterally, but also in temporal areas related to social cognition and emotional processing. Critically, this pattern of activation was notably different from the EP group. Thus, the changes in activation were consistent with the strategies trained and, combined with the cognitively-based near transfer effects, suggest that MST focused on face-name association enhances performance by engaging cognitive control and social/emotional processing. Finally, our data indicated that our MST is a relevant and efficient intervention to a-MCI.