Hypervigilance for fear after basolateral amygdala damage in humans

Area of Science:

• Neuroscience
• Psychology
• Human Neuroimaging

Background:

• Rodent studies suggest the basolateral amygdala (BLA) inhibits innate fear.
• The role of the BLA in human fear processing remains largely unknown.
• Urbach-Wiethe disease (UWD) offers a unique model for studying BLA function due to focal, bilateral damage.

Purpose of the Study:

• To investigate the inhibitory role of the BLA in human innate fear processing.
• To test if BLA damage in UWD patients leads to hypervigilance towards fear stimuli.
• To explore the translational relevance of rodent findings on BLA and fear to humans.

Main Methods:

• Neuroimaging (structural and functional) was used to confirm focal BLA damage in UWD subjects.
• A modified Stroop task assessed responses to unconsciously presented fearful faces.
• An eye-tracking emotion recognition task evaluated attention to fearful facial cues.

Main Results:

• UWD subjects with BLA damage exhibited hypervigilant responses to fearful faces, even when presented unconsciously.
• These subjects showed prolonged attention to the eyes in fearful facial expressions.
• UWD subjects demonstrated enhanced recognition of facial fear compared to controls.

Conclusions:

• This study provides the first direct human evidence for an inhibitory function of the BLA on the brain's threat vigilance system.
• Findings support the BLA's crucial role in regulating innate fear responses.
• Understanding the BLA's function has significant implications for anxiety and fear disorder research.