The Validation of a Portable Functional NIRS System for Assessing Mental Workload.

Area of Science:

• Neuroscience
• Biomedical Engineering

Background:

• Portable functional near-infrared spectroscopy (fNIRS) offers potential for brain imaging in real-world settings.
• Validation studies are crucial for portable fNIRS systems, particularly for cognitive tasks.
• Working memory (WM) involves temporary information storage and manipulation, primarily engaging the prefrontal cortex (PFC).

Purpose of the Study:

• To validate a laboratory-developed portable fNIRS system, WearLight, for imaging brain activity during working memory tasks.
• To assess prefrontal cortex (PFC) hemodynamic responses associated with varying cognitive loads in an n-back task.
• To evaluate the relationship between task performance and hemodynamic responses using the WearLight system.

Main Methods:

• Utilized a portable, wireless fNIRS system (WearLight) to monitor 25 college students during n-back working memory tasks.
• Implemented an experimental protocol with 32 task blocks across four difficulty levels.
• Computed hemodynamic responses from fNIRS data to analyze brain activation patterns.

Main Results:

• Observed incremental hemodynamic activation in the PFC corresponding to increased working memory load.
• Found greater activation in the left PFC compared to the right PFC during WM tasks.
• Demonstrated a correlation between task performance and measured hemodynamic responses.

Conclusions:

• The WearLight portable fNIRS system successfully imaged cognitive load, proving its functionality.
• The system's wearable and wireless nature enables brain imaging in naturalistic environments.
• Results support the development of user-friendly brain-computer interfaces using portable fNIRS technology.