Existing semantic knowledge provides a schematic scaffold for inference in early cognitive decline, but not in amnestic MCI

ABSTRACT

Healthy older adults show impaired relational learning, but improved transitive expression when inferences are made across pre-experimentally known premise relations. Here, we used the transitivity paradigm to ask whether the organizational structure within schemas facilitates the bridging of relations for novel inference for otherwise healthy older adults who are exhibiting early signs of cognitive decline (“at-risk” older adults), and individuals with single- or multiple-domain amnestic mild cognitive impairment (aMCI). Relational learning was impaired in the two older adult groups, but transitive expression was facilitated by prior semantic knowledge of relations. Prior semantic knowledge did not improve novel inference for aMCI individuals. Schematic scaffolding can successfully support inference in preclinical cognitive decline, but such cognitive support may no longer be useful later in the disease process when dysfunction in neural circuitry may be too severe. The findings encourage future work of semantic knowledge and inference in larger samples of aMCI cases.

KEYWORDS:

• Memory
• semantic memory
• relational memory
• inference
• aging
• mild cognitive impairment

Acknowledgements

This research was supported by a Canadian Institutes of Health Research (CIHR) Operating Grant awarded to J.D.R. (MOP-126003), a postdoctoral fellowship from CIHR awarded to M.C.D., and funding from the Ontario Ministry of Health and Long-Term Care through the Ontario Research Coalition of Research Institutes/Centres on Health & Aging (ORC) awarded to M.C.D. R.S.R. acknowledges support from a VISTA York Research Chair and NSERC.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Canadian Institutes of Health Research [Grant Number MFE129852]; Institute of Aging: [Grant Number MOP-126003].