Representational dynamics during fear memory extinction in the human brain (iEEG)

• Human iEEG work characterizes representational dynamics during extinction of fear memories (Nature).¹
• Results inform neural decoding and dynamics in limbic and cortical circuits.^{1 1}

Gardner updates

• Human iEEG work shows representational dynamics during fear memory extinction, informing neural decoding and dynamics in limbic and cortical circuits (Nature). ¹

Weekly enrichment (2026-07-20)

• The underlying study is “Representational dynamics during extinction of fear memories in the human brain,” published in Nature Human Behaviour (2025), by researchers at the Universitat Autònoma de Barcelona and Ruhr-Universität Bochum (PMID 40764405).²³
• Recordings were intracranial EEG (iEEG) in epilepsy patients, giving direct electrophysiological access to deep structures of the fear/extinction network including the amygdala, hippocampus and prefrontal cortex.²⁴
• The analysis combined iEEG with representational similarity analysis (RSA), a method that quantifies how brain regions represent specific cues and contexts, to track memory traces across learning and test phases.²⁴
• A central finding is that amygdala theta oscillations (4–12 Hz) during extinction learning signal safety rather than threat, translating a mechanism previously shown in rodents into the human brain.²⁴
• Extinction memory traces were characterized by stable, context-specific neural representations that were coordinated across the extinction network, consistent with engram-based, context-dependent suppression of the original fear memory.²
• Context specificity in the lateral prefrontal cortex (lPFC) during extinction learning predicted the later reoccurrence of fear memory traces, while reoccurrence of extinction traces predicted safety responses.²
• The authors frame the mutual competition between fear and extinction memory traces as a mechanistic basis for fear renewal and extinction retrieval, phenomena central to relapse in anxiety and PTSD treatment.²⁴
• Clinically, mapping where and when extinction representations form and compete could guide targets for closed-loop stimulation and exposure-therapy augmentation in anxiety disorders.²⁴

Footnotes

1. https://news.google.com/rss/articles/CBMiX0FVX3lxTE53TGI4YWdvMllWeFp4TTVBanJOSm83T2laYXFKeDNJZjl5WDRyRll0R3JQNFBZY3FUT2FIVUh3UmdzbUZ6TU1vVUFzUE42Q0JFREE5d1gwWUF2X3g1enJj?oc=5 ↩ ↩² ↩³ ↩⁴

2. https://www.nature.com/articles/s41562-025-02268-5 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

3. https://pubmed.ncbi.nlm.nih.gov/40764405/ ↩

4. https://neurosciencenews.com/fear-memory-extinction-29658/ ↩ ↩² ↩³ ↩⁴ ↩⁵