**📅 Date:** ➤ ⌈[[2025-02-11-Tue〚Monetary Policy Tools ▪The Split-Brain〛]] ⌋ **💭 Note:** #👾/Question • If split-brain patients show independent hemispheric function, could a normal brain contain multiple semi-independent consciousnesses? • Why does the optic nerve cross over, but other sensory systems do not? • Could a future brain-computer interface allow for multi-core human cognition, expanding our processing power? ⇩ 🅻🅸🅽🅺🆂 ⇩ **🏷️ Tags**: #🧠/Neuro-Science **🗂 Menu**: ⌈[[✢ M O C ➣ 02 ⌈F E B - 2 0 2 5⌉ ✢|2025-F E B-MOC]]⌋ ➤ ⌈[[Language Centres in the Human Brain]]⌋ ➤ ⌈[[Savant Syndrome & The Existence of Consciousness]]⌋ ➤ ⌈[[🧠 Quantum Consciousness, Fields, and Meaning]]⌋ **🌐 Link**: [Nature-The split brain: A tale of two halves](https://www.nature.com/articles/483260a) ---   ## I. The Structure and Role of the Corpus Callosum ![[Corpus Callosum.png|#left|300]] - The **corpus callosum** (胼胝体) is a bundle of nerve fibers that connects the left and right hemispheres of the brain. - ![[corpus callosum 胼胝体.png|#left|300]] • It allows the hemispheres to **communicate and share information**, ensuring coordinated movement and cognition. ## II. Split-Brain Surgery and Epilepsy Treatment • **Dr. William Van Wagenen** pioneered **split-brain surgery** (裂脑手术) as a treatment for severe epilepsy. - ![[Pasted image 20250211222217.png|#left|200]] • **Epilepsy** results from excessive, unregulated electrical signals in the brain, which can cause seizures.(癫痫是由于大脑内过度、不受控制的电信号活动引起的，这些异常放电可能导致癫痫发作) • By severing the corpus callosum, these signals **can no longer spread between hemispheres**, reducing seizure severity. ### 👀 Consciousness and Split-Brain Patients • A major question: **If the brain is split, does the patient have one consciousness or two?** • Research by **Roger Sperry and Michael Gazzaniga** showed that split-brain patients exhibit **independent processing in each hemisphere**: ![[Pasted image 20250211224436.png]] • When an image is presented to the **left visual field**, the **right hemisphere** recognizes it but **cannot verbalize it** (since the left hemisphere controls speech). • When the same image is presented to the **right visual field**, the **left hemisphere** recognizes and verbalises it. • This suggests **the brain can function as two separate, semi-independent entities** after the surgery. ----- ### III. Why Does Each Hemisphere Control the Opposite Side? • **Left hemisphere** controls the **right side** of the body. • **Right hemisphere** controls the **left side** of the body. • **Theories:** 1. **Body Avoidance Theory** - This adaptation **might help prevent collisions** when moving. 2. **Double Reversal Theory** – - Early ancestors may have originally moved **backward**, and as we evolved, the nervous system adapted but retained the cross-wiring. 3. **Neither theory explains why the optic nerves also cross over** - creating **contralateral vision**. ### Brain Hemispheres and Cognitive Specialization • **Left Hemisphere:** Logical thinking, language, analytical skills. • **Right Hemisphere:** Creativity, intuition, spatial awareness. • **This dual-system design is like a dual-core processor, ensuring the brain processes information efficiently.** ![[Brain Lateralisation.png]] ### Broader Implications: Consciousness and Multi-Core Cognition • **Split-brain research raises deep philosophical questions:** • Is our consciousness truly **unified**, or is it **two systems working in sync**? • Could each hemisphere **develop independent awareness** if completely isolated? • **Alien Hand Syndrome**: Some split-brain patients experience a **“rebellious” hand**, suggesting the two hemispheres have **separate intentions**.