Comparison of local activation, functional connectivity, and structural connectivity in the N-back task

Area of Science:

• Cognitive Neuroscience
• Neuroimaging

Background:

• The N-back task is a standard tool for studying working memory.
• Previous fMRI studies linked N-back task difficulty to local brain activation.
• Limited research explored whole-brain functional connectivity changes during N-back tasks.

Purpose of the Study:

• To compare functional connectivity and local activation alterations with N-back task difficulty.
• To investigate the relationship between structural connectivity and N-back task accuracy using DTI.

Main Methods:

• Functional magnetic resonance imaging (fMRI) to assess brain activation and functional connectivity.
• Diffusion tensor imaging (DTI) to evaluate structural connectivity.
• Comparison of brain activity across different N-back task difficulties.

Main Results:

• Functional connectivity changes varied distinctly from local activation patterns based on task difficulty.
• The 2-back task demonstrated unique utility for working memory investigation.
• Top structural connectivities correlated with 2-back task accuracy were also locally activated.

Conclusions:

• Local activation and functional connectivity reflect different neural events during N-back tasks.
• The 2-back task is optimal for probing working memory.
• Both fMRI and DTI are valuable for predicting 2-back task performance.