Daniel Böttger describes his experience after brain surgery for cancer removed his right amygdala, resulting in the complete elimination of visceral fear, depression, and most suffering, while also causing some social difficulties and autism-like symptoms. Longer summary

Daniel Böttger, who previously contributed ACX book reviews and consciousness theories, provides an update after his 2024 brain cancer diagnosis and treatment. He underwent multiple neurosurgeries to remove an astrocytoma, with collateral damage including his right amygdala, part of his hippocampus, and temporal cortex. The post details his surprisingly cheerful journey through six surgeries and experimental chemotherapy, during which he noticed he could no longer feel visceral fear or depression. He explores the neurological basis for these changes, focusing on how losing his right amygdala eliminated the fight-or-flight response while leaving abstract risk assessment intact. The latter part discusses both benefits (elimination of fear, depression, and suffering; possible IQ increase) and drawbacks (reduced ability to read facial expressions, difficulty empathizing with others' fears, autism-like symptoms). He advocates for considering amygdalectomy as a treatment for certain psychiatric disorders, noting modern techniques like stereotactic radiosurgery are far safer than historical lobotomies. Shorter summary