Multiscale Entropy as a New Feature for EEG and fNIRS Analysis.

Area of Science:

• Neuroscience
• Cognitive Science
• Biomedical Engineering

Background:

• Memory formation and selective retention are complex neurocognitive processes.
• Existing approaches have limitations in fully understanding memory mechanisms.
• Multimodal brain imaging offers enhanced insights into brain function.

Purpose of the Study:

• To apply multiscale entropy (MSE) for analyzing brain complexity during a memory task.
• To utilize simultaneous electroencephalogram (EEG) and functional near-infrared spectroscopy (fNIRS) for brain functional analysis.
• To investigate brain activity patterns associated with intentional memory encoding and forgetting.

Main Methods:

• Simultaneous EEG/fNIRS recordings were obtained from 15 healthy participants.
• Participants performed a visual memory task involving deciding to remember or forget presented scenes.
• MSE was applied to analyze brain complexity levels in different brain regions.

Main Results:

• Significantly greater brain complexity levels were observed in the prefrontal and frontal lobes when participants intentionally memorized visual scenes compared to when they intended to forget them (p < 0.05).
• The study demonstrated the feasibility of using simultaneous EEG/fNIRS for functional brain analysis.
• MSE emerged as a potential indicator for this multimodal approach.

Conclusions:

• Simultaneous EEG/fNIRS is a viable approach for brain functional analysis.
• MSE analysis can effectively quantify brain complexity levels.
• Brain complexity in frontal regions is associated with the intentional encoding of memories.