Functional neuroimaging in subjective cognitive decline: current status and a research path forward

Area of Science:

• Neuroscience
• Cognitive Aging
• Medical Imaging

Background:

• Subjective cognitive decline (SCD) is a perceived worsening of cognition without objective deficits.
• SCD may precede dementia, but requires objective biomarkers for intervention.
• Current biomarkers are often disease-specific, limiting application in unclear etiologies.

Purpose of the Study:

• To review functional neuroimaging studies in subjective cognitive decline.
• To reconcile inconsistent findings in the literature.
• To propose a functional model for SCD and guide future research.

Main Methods:

• Review of functional neuroimaging studies investigating subjective cognitive decline.
• Analysis of data to identify patterns and inconsistencies.
• Development of a theoretical functional model based on network dynamics.

Main Results:

• Functional neuroimaging may detect subtle brain changes associated with SCD.
• Inconsistent findings suggest variability in underlying pathophysiology or measurement sensitivity.
• A proposed model highlights noisy signal propagation and inefficient processing in brain networks.

Conclusions:

• Functional neuroimaging offers a disorder-agnostic approach to track cognitive decline.
• The proposed model suggests network dysfunction underlies the subjective experience of cognitive decline.
• Future research should focus on refining neuroimaging techniques and validating the functional model.