Neuroplasticity
I was listening to the Huberman Lab episode on neuroplasticity and kept pausing it to write things down. I was trying to understand why changing habits feels so much harder as you get older, and this episode answered a lot of that.
From ages 1 to 25, your brain is essentially learning and pruning at the same time. Connections that aren't reinforced get dropped. After around 14 or 15, neurogenesis becomes very rare. I was surprised to learn it mostly only happens in the olfactory bulb and hippocampus. So the idea that you can just grow new neurons as an adult is largely not how it works.
What you can do is add or strengthen synapses. That means you can unlearn emotional and traumatic experiences by replacing them with something else. But the catch is that after your early years, you have to be deliberate about it. As a kid you do it automatically because your neural connections are still consolidating. I was trying to understand why adults need so much more intention to change anything, and that was basically the answer. Later in life the brain does release certain chemicals when it self-recognises that change is needed, but you cannot add new connections, only replace what's already there.
The part I found most interesting was the two neurochemicals involved in learning: epinephrine, released from the locus coeruleus only in high focus states, and acetylcholine. Both get released across multiple sites in the brain and highlight the specific circuits responsible for change. I was trying to figure out how to actually trigger this deliberately. Turns out you have to genuinely pay careful attention. The brain needs to register that something matters before it will bother encoding it.
Mental focus follows visual focus. When we are relaxed, our eyes move slightly inward and this triggers epinephrine release. One thing I want to try is spending 60 to 120 seconds focusing hard on a small object before a work session. Huberman says it genuinely increases brain activity for focus. Also interesting was the nicotine bit. Nicotine receptors are involved in hyper-alertness, which is why some people reach for it before they need to concentrate. Too much, though, and the brain dissociates from the effect entirely.
For building the actual conditions for change he talked about fixing sleep, using accountability partners, using shame by posting publicly, or dedicating the effort to someone you care about. Basically come up with a fear or love-based reason to be alert and present for the task.
Still want to look into: Keller theory, and the David Nobel Prize neuroscience experiment.