For learning and self-improvement, Huberman recommends:

1. Identifying when you are most alert and focusing learning during those times. 
2. Practicing 90-minute focused learning periods within your ultradian cycles, with breaks in between. Start gradually and don't expect full focus at first.
3. Using visual focus techniques to activate acetylcholine release. This could be staring at a fixed point or reducing peripheral vision.
4. Taking 20-minute non-sleep deep rest periods after focused learning. This could involve lying down with eyes closed and no sensory input.

1. Prioritizing high-quality sleep for memory consolidation after focused learning. 

• Considering the use of supplements or medications to boost acetylcholine in moderation and under medical guidance.  
• Balancing intense focus with mindless, repetitive activities that activate the reward system, like walking, running, or cycling.

• Neural plasticity allows us to learn, adapt and improve at any age but requires effort after early development.
• Releasing acetylcholine through visual focus techniques can activate plasticity for learning.
• Practicing focused attention for learning in alertness periods, followed by rest, enhances memory and brain change.
• A balanced approach of focus, rest, sleep, and mindless repetition aids self-improvement.