Item-Level Scores on the Boston Naming Test as an Independent Predictor of Perirhinal Volume in Individuals with Mild Cognitive Impairment

We explored the methodological value of an item-level scoring procedure applied to the Boston Naming Test (BNT), and the extent to which this scoring approach predicts grey matter (GM) variability in regions that sustain semantic memory. Twenty-seven BNT items administered as part of the Alzheimer's Disease Neuroimaging Initiative were scored according to their sensorimotor interaction (SMI) value. Quantitative scores (i.e., the count of correctly named items) and qualitative scores (i.e., the average of SMI scores for correctly named items) were used as independent predictors of neuroanatomical GM maps in two sub-cohorts of 197 healthy adults and 350 mild cognitive impairment (MCI) participants. Quantitative scores predicted clusters of temporal and mediotemporal GM in both sub-cohorts. After accounting for quantitative scores, the qualitative scores predicted mediotemporal GM clusters in the MCI sub-cohort; clusters extended to the anterior parahippocampal gyrus and encompassed the perirhinal cortex. This was confirmed by a significant yet modest association between qualitative scores and region-of-interest-informed perirhinal volumes extracted post hoc. Item-level scoring of BNT performance provides complementary information to standard quantitative scores. The concurrent use of quantitative and qualitative scores may help profile lexical-semantic access more precisely, and might help detect changes in semantic memory that are typical of early-stage Alzheimer's disease.

Automated summary

This study explored the methodological value of item-level scoring on the Boston Naming Test (BNT) and its ability to predict grey matter variability in regions involved in semantic memory. The results showed that item-level scoring of BNT performance provides complementary information to standard quantitative scores and may help detect changes in semantic memory associated with early-stage Alzheimer's disease. The use of both quantitative and qualitative scores could help profile lexical-semantic access more precisely.