Fig. 1

Diagram based on Didic et al.’s [12] model. It maps the two tests investigated here (VSTMBT and FCSRT) onto the stages of AD. It follows the rationale of the model to suggest when along the continuum, these tests could become most informative. Stage III of Braak [20, 21] corresponds to the onset of MCI (spread of pathology from the anterior medial temporal lobe (MTL) network to the posterior network). Based on the above hypothesis and that proposed by Parra [22], we predicted that the VSTMBT, as a context-free memory test, would inform on the risk of progressing from normal to pathological ageing (e.g. early MCI or objectively defined subtle cognitive decline [23]) while the FCSRT, as a context-rich memory test, would inform on the risk of progressing to AD dementia