Minimum detectable change in motor and prefrontal cortex activity over repeated sessions using 3T functional MRI and...

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Brain Activity Measurement

Background:

• Functional magnetic resonance imaging (fMRI) is crucial for studying brain activity.
• Assessing the reliability of fMRI measurements across repeated sessions is vital for longitudinal research.

Purpose of the Study:

• To establish the minimum detectable change (MDC) with 95% confidence for fMRI measures.
• To evaluate fMRI's suitability for serial investigations of individual brain activity using a block design.

Main Methods:

• Fourteen participants underwent three fMRI sessions, performing motor and working memory tasks.
• Region-of-interest analysis of variance (ANOVA) was used to calculate MDC for activated volume, signal change, and voxel locations.

Main Results:

• The MDC for activated brain volume ranged from 5.0-8.8 cm³.
• The MDC for percent signal increase was 0.3%-0.6%, and for the center of mass of activity was 3-4 mm.

Conclusions:

• fMRI measures of activity strength and center of mass are sensitive to changes over repeated sessions.
• fMRI is a reliable tool for serial investigations of individual brain activity with simple tasks and block designs.