Nature vs. Nurture: The Great Debate! 🤔
❓ The Big Question
- Is brain preprogrammed? 🧬🎯
- Or shaped by environment? 🌍📡
- Answer: BOTH! 🤝
🌍 Evidence for Environment
👁️ Hubel & Wiesel's Kitten Experiments
- Removed one eye early 🐱👁️✂️
- Visual cortex for that eye degenerates! 🧠⬇️
- Other eye's area EXPANDS! 📈⬆️
- Neurons take over vacant space! 🎯
👃 Rat Whisker Experiments
- Remove whiskers 🐀👃✂️
- Barrel cortex degenerates 💀
- Neighboring neurons get bigger! 📈
🎻 Violin Players' Brains
- MRI scans show enlarged finger areas! 🧲👆
- Practice = Bigger brain areas! 🏋️🧠⬆️
- Use it or lose it! 💪
⚡ Sur's Rewiring Experiment
- Connected visual nerves to auditory cortex! 👁️➡️👂
- Visual cortex developed in auditory areas! 🧠🔄
- Environment wins! 🌍✅
🧬 Evidence for Genetic Programming
🐔 Hamburger's Chick Experiments
- Cut spinal cord at various stages ✂️🦴
- Brain still developed normally! 🧠✅
- No feedback needed! 📡❌
- Autonomous development! 🎯
🧠 Preprogrammed Cells
- Some cells respond to only ONE stimulus! 📡
- Rizzolatti: Neurons have specific functions! 🎯
🌱 Adult Neurogenesis: NEW!
🐦 Birds Grow Neurons for Songs!
- Before mating season = New cells! 🎵💕
- Evolutionary benefit! 🧬✨
🐀 Rats Grow Hippocampus Cells!
- 2,000 new neurons per hour! ⏱️🧠
- While learning tasks! 📚🐭
👤 Humans Too!
- Association cortex grows new cells! 🧠🌱
- Experience reorganizes cortex! 🔄
- Stem cell research = Hope! 🌟💔
📊 Quick Development Timeline
- Heart beats: 3 weeks ❤️
- 1st NS reflex: 8 weeks 🔌
- Swallowing: 11 weeks 🍼
- Stretching: 22 weeks 🤸
- Sucking: 29 weeks 👶
🔑 Key Takeaways
- Environment AND genes both matter! 🌍🧬
- Brain is plastic (changeable)! 🔄💪
- Use = Growth! 📈
- Deprivation = Degeneration! ⬇️💀
- Adult brains CAN grow new neurons! 🌱✨
- The debate continues! 🤔🔬