Effective connectivity of the multiplication network: a functional MRI and multivariate Granger Causality Mapping...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Functional Neuroimaging

Background:

• Mental calculation relies on a fronto-parietal network, but its effective connectivity remains unclear.
• Understanding brain network dynamics is crucial for explaining individual differences in arithmetic skills.

Purpose of the Study:

• To map the effective connectivity of the brain network during mental calculation.
• To compare connectivity patterns between individuals with high and low arithmetic competence (AC).

Main Methods:

• Employed event-related functional magnetic resonance imaging (fMRI) combined with multivariate Granger Causality Mapping (GCM).
• Participants performed a multiplication verification task involving single and double-digit problems.

Main Results:

• Identified a fronto-parietal network including bilateral intraparietal sulcus (IPS), left pre-supplementary motor area (PreSMA), left precentral gyrus (PreCG), and right dorsolateral prefrontal cortex (DLPFC).
• Revealed distinct network dynamics: high AC group showed greater right IPS activation and relied on IPS-IPS circuits, while the low AC group utilized DLPFC-IPS circuits more.
• Demonstrated IPS-IPS circuits for numerical quantity and DLPFC-IPS circuits for operation management, supported by PreCG and PreSMA.

Conclusions:

• Multivariate GCM effectively reveals effective connectivity in mental calculation processes.
• Arithmetic competence is associated with differential recruitment and connectivity within fronto-parietal networks.