Within-Individual BOLD Signal Variability and its Implications for Task-Based Cognition: A Systematic Review.

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Functional Magnetic Resonance Imaging (fMRI)

Background:

• Within-individual blood oxygen level-dependent (BOLD) signal variability, representing intrinsic moment-to-moment fluctuations, is an emerging metric in neuroimaging.
• This metric is hypothesized to provide unique information not captured by traditional mean-based analyses.
• Understanding the role of intrinsic BOLD signal fluctuations in cognitive performance necessitates a synthesis of existing literature.

Approach:

• This systematic review integrates studies examining within-individual BOLD signal variability across various cognitive domains.
• Literature searches were conducted on PubMed and APA PsycInfo for papers published up to October 17, 2022.
• Included studies employed within-individual BOLD signal variability methodology in task-based fMRI and/or correlated it with behavioral performance.

Key Points:

• Results indicate that patterns of BOLD signal variability in cognitive tasks vary across the lifespan (ages 7-85).
• These variability patterns are influenced by task demands, measurement techniques, quantification methods, and age.
• The review included 19 empirical studies, with data extraction and quality assessment performed systematically.

Conclusions:

• Within-individual BOLD signal variability shows promise as a meaningful metric for understanding neurocognitive performance at an individual level.
• Further research with consistent methodologies and measures is needed to fully conceptualize its impact on cognitive abilities in diverse populations.
• Future studies should explore underrepresented cognitive domains and populations to enhance understanding of BOLD variability's role.