Cortical functional connectivity decodes subconscious, task-irrelevant threat-related emotion processing.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Affective Neuroscience

Background:

• The role of cortical structures in subconscious processing of salient stimuli remains debated.
• Existing hypotheses include the 'low-road' (subcortical) and 'many-roads' (cortical involvement) models.
• Understanding these pathways is key to deciphering rapid threat detection mechanisms.

Purpose of the Study:

• To investigate the extent of cortical involvement in subconscious processing of fearful stimuli.
• To compare the predictive information contained in different functional connectivity (FC) patterns (cortical-cortical, cortical-subcortical, subcortical-subcortical).
• To identify specific FC networks that decode subliminal fear perception.

Main Methods:

• Utilized whole-brain functional connectivity (FC) analysis.
• Employed machine learning classifiers trained on data from separate subject groups.
• Examined classification accuracy based on the number of selected FC features.

Main Results:

• Cortical-cortical and cortical-subcortical FC contained significantly more information for predicting subliminal fearful face processing than subcortical-subcortical FC.
• Achieved 92% classification accuracy using the top 8 FC features.
• Identified increased FC between the right amygdala and precuneus during subliminal fear, alongside decreased amygdala FC, suggesting bilateral decoupling.

Conclusions:

• Cortical structures are actively engaged and essential for subconscious processing of fear.
• Specific FC patterns, particularly involving the amygdala, precuneus, angular gyrus, middle temporal gyrus, and cerebellum, decode subliminal affective stimuli.
• Findings support a more extensive role for the cortex in rapid, subconscious threat evaluation than previously assumed.