Serial position effects reflect the integrity of distinct brain regions in Major and Minor Neurocognitive Disorder

Serial Position Effects (SPE) in wordlist learning provide a rich set of metrics of cognitive functioning. In this study, we systematically mapped the neuroanatomical correlates of SPEs across delays in Major and Minor Neurocognitive disorders. Primacy, middle, and recency SPE scores of the California Verbal Learning Test at Learning, Short delay, and Long delay in healthy controls and patients with neurodegenerative disease were correlated with MRI gray matter signal intensities (voxel-based morphometry, VBM). The VBM analyses revealed distinct patterns of brain-behavioral correlations depending on both the SPE and the time-point. Unlike patients, the healthy controls performance incrementally improved recall of primacy items from Learning to Short and to Long delay, i.e., primacy progression. Moreover, the proportion of correct primacy items recalled at long delay compared to Learning correlated with bilateral medial temporal lobe regions, which commonly bear the brunt of pathology of Alzheimers disease. The results implicate the primacy progression score as an accessible and sensitive measure for disease detection, progression, and therapeutic response in Major and Minor Neurocognitive disorders.