Biomarkers

Area of Science:

• Neuroscience
• Cognitive Science
• Medical Imaging

Background:

• Neural activity during cognitive tasks correlates with neuronal effort.
• Functional magnetic resonance imaging (fMRI) studies neural activity differences.

Purpose of the Study:

• Investigate neural activity differences between normal cognition (NC) and amnestic mild cognitive impairment (aMCI) during object-location association (OLA) tasks.
• Determine if neural activity patterns can serve as biomarkers for distinguishing NC from aMCI.

Main Methods:

• Utilized an event-related fMRI paradigm with 43 participants (19 NC, 24 aMCI).
• Analyzed blood-oxygen-level-dependent (BOLD) signals during novel and repeated OLA trials.
• Employed hemodynamic response function (HRF) deconvolution to evaluate neural activity in functional brain networks.

Main Results:

• aMCI individuals exhibited significantly weaker neural activity than NC in the right executive control network (RECN), particularly in novel trials.
• NC individuals showed lower neural activity in repeated trials, suggesting enhanced information processing capacity.
• Time-varying neural activity in RECN and visuospatial regions differed significantly between groups (p < 0.05).
• A linear Support Vector Machine (SVM) model achieved 86% accuracy in classifying NC and aMCI using five key neural activity features.

Conclusions:

• aMCI is associated with reduced neural activity in RECN regions during OLA tasks, especially for novel stimuli.
• Time-varying neural activity during OLA tasks shows potential as a biomarker for differentiating between NC and aMCI.