My simple hack for increased alertness and improved cognitive functioning: very bright light
This is a simple idea that I came up with by myself. I was looking for a means to enter high functioning lots-of-beta-waves modes without the use of chemical stimulants. What I found was that very bright light works really, really well.
I got the brightest light bulbs I could get cheaply. 105 watts of incandescents with halogen gas, billed as the equivalent of 130 watts of incandescent light. And I got an adaptor like this that lets me screw four of those into the same socket in the ceiling. The result is about as painful to look at as the sun. It makes my (small) room brighter than a clear summer's day at my latitude and slightly brighter than a supermarket.
I guess it affects adenosine much like caffeine does because that's what it feels like. Yet unlike caffeine, it can be rapidly turned on and off, literally with the flip of a switch.
For waking up in the morning, I find bright light more effective than a 200mg caffeine tablet, although my caffeine tolerance is moderate for a scientist.
I have not compared the effects of very bright light to modafinil, which requires a prescription in my country.
When under this amount of light, I need to remind myself to go to bed, because I tire about three hours later than with common luminosity. Yet once I switch it off, I can usually sleep within a few minutes, as (I'm guessing) a flood of unblocked adenosine suddenly overwhelms me. I used to have those unproductive late hours where I was too awake to sleep but too tired to be smart. I don't have those anymore.
You've probably heard of light therapy, which uses light to help manage seasonal affective disorder. I don't have that issue, but I definitely notice that the light does improve my mood. (Maybe that's simply because I like to function well.) I'm pretty sure the expensive "light therapy bulbs" you can get are scams, because the color of the light doesn't actually make a difference. The amount of light does.
One nice side benefit is that it keeps me awake while meditating, so I don't need the upright posture that usually does that job. Without the need for an upright posture, I can go beyond two hours straight, which helps enter more profoundly altered states.
After about 10 months of almost daily use of this lighting, I have not noticed any decrease in effectiveness. I do notice I find normally-lit rooms comparatively gloomy, and have an increasingly hard time understanding why people tolerate that. Supermarkets and offices are brightly lit to make the rats move faster - why don't we do that at our homes and while we're at it, amp it up even further? After all, our brains were made for the African savanna, which during the day is a lot brighter than most apartments today.
Since everyone can try this for a few bucks, I hope some of you will. If you do, please provide feedback on whether it works as well for you as it does for me. Any questions?