What would be mechanism of action of sugar for a healthy individual? Blood glucose levels are kept in a pretty narrow band, so eating sugar generates insulin spike, and unless you just exercised and have depleted muscle glycogen storage it gets converted straight into fat. Insulin spikes also cause sleepiness.
Modafinil works extremely badly on me - it masks lack of sleep well enough, but it makes my mental performance extremely low, and makes me very irritable and unfriendly. Basically I get all side effects of sleep deprivation except I'm not aware of needing some sleep.
I have mixed experience with caffeine and amphetamine-like drugs. They seem to be useful for tiredness and focus enhancements to a degree.
Even small glucose levels can apparently have significant effects. I have some papers in my library arguing that the memory-enhancing effects of adrenaline (which doesn't cross the blood brain barrier) are mediated by the glucose increase it causes. One of them demonstrated that a glucose-mimetic molecule also acted as an enhancer. Overall, the data seems pretty convincing that getting a suitable dose of glucose is enhancing, but the effect has an inverted-U curve - there is an individual and task dependent optimal level.
Overall, drug responses are very in...
Transhumanists have high hopes for enhancing human cognitive abilities in the future. But what realistic steps can we take to enhance them now? On the one hand Flynn effect suggests IQ (which is a major factor in human cognition) can be increased a lot with current technology, on the other hand review of existing drugs seems rather pessimistic - they seem to have minor positive effect on low performers, and very little effect on high performers, what means they're mostly of therapeutic not enhancing use.
So, fellow rationalists, how can we enhance our cognition now? Solid research especially welcome, but consistent anecdotal evidence is also welcome.