Additive and interaction effects of working memory and motor sequence training on brain functional connectivity

Area of Science:

• Neuroscience
• Cognitive Psychology
• Rehabilitation Science

Background:

• Shared neural mechanisms link working memory (WM) and motor sequence learning (MSL).
• The impact of sequential versus combined training on brain functional connectivity (FC) remains understudied.

Purpose of the Study:

• Investigate changes in brain FC following sequential (WM+MSL, MSL+WM) and combined (WM×MSL) training.
• Determine additive and interactive effects of training order on cognitive performance and FC.

Main Methods:

• 54 healthy adults participated in 6 weeks of cognitive training with functional MRI assessments.
• A double-baseline approach controlled for practice effects.
• Linear mixed-effects models and t-tests analyzed performance; FSL analyzed resting-state fMRI data.

Main Results:

• All training groups showed improvements in processing speed, verbal WM, and manual dexterity.
• Motor sequence learning followed by working memory (MSL+WM) training yielded additive benefits in processing speed and verbal WM.
• Training increased FC in a network including the angular gyrus, superior temporal sulcus, superior parietal gyrus, middle temporal gyri, and precentral gyrus.

Conclusions:

• Distinct patterns of resting-state FC modulation emerge based on the order of WM and MSL training.
• The sequence of training influences cognitive outcomes and neural connectivity.
• Findings suggest optimizing training protocols for rehabilitation by considering the order of skill acquisition.