Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017;4(2):87-92.
doi: 10.14283/jpad.2017.9.

Short-Term Practice Effects and Amyloid Deposition: Providing Information Above and Beyond Baseline Cognition

K Duff  1 , D B Hammers  1 , B C A Dalley  1 , K R Suhrie  1 , T J Atkinson  1 , K M Rasmussen  2 , K P Horn  2 , B E Beardmore  2 , L D Burrell  2 , N L Foster  1 , J M Hoffman  2
Affiliations

Short-Term Practice Effects and Amyloid Deposition: Providing Information Above and Beyond Baseline Cognition

K Duff et al. J Prev Alzheimers Dis. 2017.

Abstract

Background: Practice effects, which are improvements in cognitive test scores due to repeated exposure to testing materials, may provide information about Alzheimer's disease pathology, which could be useful for clinical trials enrichment.

Objectives: The current study sought to add to the limited literature on short-term practice effects on cognitive tests and their relationship to amyloid deposition on neuroimaging.

Participants: Twenty-seven, non-demented older adults (9 cognitively intact, 18 with mild cognitive impairment) received amyloid imaging with 18F-Flutemetamol, and two cognitive testing sessions across one week to determine practice effects.

Results: A composite measure of 18F-Flutemetamol uptake correlated significantly with all seven cognitive tests scores on the baseline battery (r's = -0.61 - 0.59, all p's<0.05), with higher uptake indicating poorer cognition. Practice effects significantly added to the relationship (above and beyond the baseline associations) with 18F-Flutemetamol uptake on 4 of the 7 cognitive test scores (partial r's = -0.45 - 0.44, p's<0.05), with higher uptake indicating poorer practice effects. The odds ratio of being "amyloid positive" was 13.5 times higher in individuals with low practice effects compared to high practice effects.

Conclusions: Short-term practice effects over one week may be predictive of progressive dementia and serve as an affordable screening tool to enrich samples for preventative clinical trials in Alzheimer's disease.

Keywords: Cognition; PET; amyloid deposition; practice effects.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest: Drs. Duff, Foster, and Hoffman received funding to support this project from GE Healthcare, who produces 18F-Flutemetamol.

References

    1. McCaffrey RJ, Duff K, Westervelt HJ. Practitioner’s Guide to Evaluating Change with Neuropsychological Assessment Instruments. New York: Plenum/Kluwer; 2000.
    1. Granholm E, et al. Age-related practice effects across longitudinal neuropsychological assessments in older people with schizophrenia. Neuropsychology. 2010;24(5):616–24. - PubMed
    1. Rapport LJ, et al. Full scale IQ as a mediator of practice effects: The rich get richer. The Clinical Neuropsychologist. 1997;11(4):375–380.
    1. Calamia M, Markon K, Tranel D. Scoring higher the second time around: meta-analyses of practice effects in neuropsychological assessment. Clin Neuropsychol. 2012;26(4):543–70. - PubMed
    1. Cooper DB, et al. Category fluency in mild cognitive impairment: reduced effect of practice in test-retest conditions. Alzheimer Dis Assoc Disord. 2004;18(3):120–2. - PubMed

LinkOut - more resources