Behavioral (reaction time) and prefrontal cortex response revealed differences in grief vs. sadness perception

Area of Science:

• Neuroscience
• Psychology
• Cognitive Science

Background:

• Basic emotion research has identified over 20 states, but differentiating similar emotions like grief and sadness remains difficult due to overlapping facial expressions.
• Understanding the distinct neural underpinnings of grief and sadness is crucial for advancing emotion science.

Purpose of the Study:

• To investigate the behavioral and neural mechanisms differentiating grief and sadness perception.
• To compare prefrontal cortex (PFC) activity during the perception of grief and sadness using neuroimaging.

Main Methods:

• Participants categorized and rated facial images depicting grief and sadness.
• Behavioral data (reaction times, ratings) and prefrontal cortex (PFC) hemodynamic activity (oxy-Hb) using functional near-infrared spectroscopy (fNIRS) were collected.
• Cultural differences in emotional responses were also examined.

Main Results:

• Explicit behavioral ratings did not significantly differ between grief and sadness.
• Implicit measures (reaction times) revealed distinctions in perception.
• Increased oxy-Hb in the right dorsolateral PFC was observed for grief compared to sadness.
• Asian participants showed heightened dorsal PFC activity for unpleasant grief stimuli, indicating cultural variability.

Conclusions:

• Distinct implicit perceptual and neural processing mechanisms differentiate grief and sadness.
• These findings suggest separate automatic implicit processes govern grief and sadness.
• Cultural factors influence emotion perception and neural responses in the PFC.