Subdividing Stress Groups into Eustress and Distress Groups Using Laterality Index Calculated from Brain Hemodynamic...

Area of Science:

• Neuroscience
• Psychology
• Biomedical Engineering

Background:

• Stress impacts cognitive abilities and health, but its varying levels (eustress vs. distress) are often undifferentiated.
• Inconsistent brain activation patterns complicate stress assessment.
• Differentiating stress subtypes is crucial for accurate evaluation.

Purpose of the Study:

• To determine if subdividing stress into eustress and distress is necessary.
• To investigate brain hemodynamic responses differentiating eustress and distress.
• To establish a foundation for stress subgroup classification using neuroimaging.

Main Methods:

• Salivary alpha-amylase (sAA) screened participants into stress subgroups.
• Functional near-infrared spectroscopy (fNIRS) measured brain hemodynamic reactions.
• An emotional stimulus-response paradigm with the International Affective Picture System (IAPS) was employed.
• Laterality Index for Stress (LIS) was calculated from fNIRS signals.

Main Results:

• Both eustress and distress groups showed right frontal cortex activation.
• Eustress exhibited greater brain activity than distress, irrespective of stimuli valence.
• LIS values followed the order: eustress > control > distress.
• Distinct hemodynamic patterns support the division of stress into eustress and distress.

Conclusions:

• The study confirms the necessity of subdividing stress into eustress and distress.
• fNIRS effectively captures differential brain activity between stress subtypes.
• This research provides a neuroimaging-based foundation for classifying stress levels.