Discriminating Stress From Cognitive Load Using Contactless Thermal Imaging Devices.

Area of Science:

• Physiological measurement
• Psychophysiology
• Biomedical engineering

Background:

• Wearable devices for stress detection can be invasive and uncomfortable.
• Electrodermal activity (EDA) is a known physiological marker for psychological state changes.
• Facial thermal distribution changes are associated with physiological responses to stress.

Purpose of the Study:

• To investigate long wave infrared (LWIR) technology as a contactless method for stress detection.
• To compare facial thermal responses with electrodermal activity (EDA) as a stress indicator.
• To explore the potential of specific facial thermal patterns in discriminating between different types of stressors.

Main Methods:

• Simultaneous recording of facial thermal data and electrodermal activity (EDA) from 17 healthy subjects.
• Exposure of subjects to controlled stressors (Stroop Test, Mental Arithmetic Test) and resting conditions.
• Statistical analysis to compare thermal features between stress, non-stress, and cognitive load conditions.

Main Results:

• Significant differences in facial temperature trends were observed between stress and resting conditions.
• Temperature changes in less-studied facial regions, such as the right cheek, effectively discriminated between stress and resting states.
• Facial thermal patterns showed potential in recognizing the typology of stressors, correlating with EDA findings.

Conclusions:

• Long wave infrared (LWIR) technology is a viable contactless alternative to wearable devices for stress detection.
• Specific facial thermal patterns, including those from the right cheek, serve as reliable indicators of psychological states.
• Contactless thermal imaging holds promise for differentiating various psychological states and stressor types.