Fig. 1

Plasma Aβ levels for CN− and CN+ participants. Scatter plot presented mean with range. No significant difference was observed in plasma Aβ40 (A), whereas there were significant differences in plasma Aβ42 (B) and Aβ42/Aβ40 (C) between CN− and CN+. *p < 0.05; **p < 0.01. Aβ amyloid-β; CN−, amyloid-β-negative cognitively normal participants; CN+, amyloid-β-positive cognitively normal participants