UPDATE
Ok I spent the past two days doing hard strenuous research on the effects of caffeine on the brain. Or maybe I just listened to a book on my PDF reader. Well the book I mentioned before, Buzz, gave me a few things to consider here but not as much as I had hoped. It was a pretty broad and didn't say much about sleep and dreaming BUT there are a few things I can share. By the way, a lot of this from memory so hopefully I recall everything correctly.
Mechanism in a Nutshell
Humans have 4 types of Adenosine receptors. The caffeine molecule is closely similar to the Adenosine molecule and is able to effectively masquerade as one. Once it reaches the Adenosine receptor it is able to alter the function and block it. In the brain Adenosine acts like "brakes" and controls the slowing down neurorecptors. Caffeine does not actually make a person awake but actually blocks these receptors as effectively as putting a brick under the brake peddle preventing you from slowing down.
 Originally Posted by Wikipedia
Adenosine acts as an inhibitor neurotransmitter that suppresses activity in the central nervous system. Consumption of caffeine antagonizes adenosine and increases activity in neurotransmission including acetylcholine (ACh), epinephrine, dopamine, serotonin, glutamate, norepinephrine, cortisol, and in higher doses, endorphins which explains the analgesic effect to some users. At very high doses (exceeding 500 milligrams) caffeine inhibits GABA neurotransmission. This evidence explains why caffeine causes anxiety, insomnia, rapid heart and respiration rate.
All of that seems fine, but he thing that gets me excited is that caffeine increases ACh. However, I worry about serotonin increasing as as well. What exactly are the levels of each one? Do they negate each other? I am not sure.
 Originally Posted by livestrong.com on Serotonin
Role in Dream Formation
While serotonin levels are lower in sleep than while awake, they are at their lowest during REM sleep, also known as dreaming sleep. In effect, neurons with serotonin receptors are active during all stages of sleep until REM, so they appear to act as a "REM inhibitor" most of the time, as reported by "Sleep Research Online" in 1999. When serotonin levels drop, the neurotransmitter acetylocholine rises in the brain. This is why many anti-depressants reduce dreaming sleep, because increasing serotonin levels inhibit the rise of acetylocholine, according to sleep scientist James Pagel in his book "The Limits of Dream."
Role in Sleep Disruption
Low serotonin levels result in sleep disruption and sleep disorders, including insomnia. Stress is a common cause of low serotonin levels, resulting in a snowballing feedback cycle of disrupted sleep, depression, anxiety and fatigue during the day, according to clinical psychologist Joseph M. Carver. You can give your sleep life a jump-start by eating foods high in tryptophan, a precursor to serotonin, as well as by getting daily exercise. In general, high-carbohydrate foods like potatoes and grains have tryptophan, as do most cheeses and meats. Mindfulness practices such as meditation and yoga are also linked to higher levels of serotonin. While high levels of serotonin may lead to feelings of bliss and happiness, there can be too much of a good thing. Excess serotonin levels are toxic to the brain, and can lead to a condition known as "serotonin syndrome."
Read more: How Does Serotonin Affect Sleep? | LIVESTRONG.COM
So depending on levels of serotonin and ACh in the brain at the time, as well as the caffeine dosage and effect, this may explain the hit and miss as well as the 1 hour time window I seem to have until peak. I've noticed several times that either the dream gets cut short or there seems to be very little dream time at all.
Cognition
According to Buzz, there have been studies that seems to suggest that caffeine is helpful in monotonous data driven tasks or task that require greater focus. On the flip side, when it comes to logical reasoning there is no effect or even degraded performance. (By the way, when Buddhist monks discovered coffee they found it very useful in prolonging meditation and prayer.) Contradictorily, the opposite may be true in depending on the individual. The author suggest that the exact cognitive effect can vary from person to person. Either way, it's clear that it can greatly aid a person becoming aware within a dream. Regardless there always seems to be increased recall and vividness within 1-3 hours depending on dosage.
Tolerance
It seems that tolerance happens like this. Any time we put any drug or mind altering substance in our body the brain wants to work to normalize. The more we regularly put that substance in our body the more the brain will change to accommodate normalization. So when we constantly suppress Andenosine receptors in our body the brain can actually increase the number or receptors requiring more levels caffeine to get the same effect. This also explains why when a person addicted to caffeine suddenly quits they will tend to feel tired and lethargic. I suspect this is obviously reversible with absence.
So it seems, as with all things, moderation is the key.
I still think that the biggest challenge here is finding the right amount of caffeine so that we mentally wake up in a dream and not end up with non lucid nREM or worse insomnia.
|
|
Bookmarks