10:30 AM; no major effect that I notice throughout the day - it’s neither good nor bad. This smells like placebo (and part of my mind is going how unlikely is it to get placebo 3 times in a row!, which is just the Gambler’s fallacy talking inasmuch as this is sampling with replacement). I give it 60% placebo; I check the next day right before taking, and it is. Man!
A cup of coffee before a big exam can help your brain perform at its best. That’s because caffeine improves short-term memory and speeds up reaction times, according to New Scientist. Researchers from the National Institute on Aging found that individuals who drank more caffeine had better scores on memory tests, which explains why has been linked to a lowered risk of Alzheimer’s disease. It can also help prevent Parkinson’s disease and relieve headache pain. But don’t overdo it—too much caffeine can make you jumpy or irritable. Look out for the signs that you’re drinking too much coffee.
“In this fascinating investigation, Lisa Mosconi presents research that crosses disciplines to argue that what goes on in your brain—from your mood to your cognitive abilities—is very closely tied to what you put on your plate. In addition to being a compelling read, readers will find tips and outlines on ways they can change their diets for optimal brain health.”

This is not something you notice when you talk to Seltzer. And though our memory is probably at its peak in our early 20s, few 30-year-olds are aware of a deficit. But Seltzer considers himself a transhumanist, in the mould of the Oxford philosopher Nick Bostrom and the futuristic writer and inventor Ray Kurzweil. Transhumanists are interested in robots, cryogenics and living a really, really long time; they consider biological limitations that the rest of us might accept, or even appreciate, as creaky obstacles to be aggressively surmounted. On the ImmInst (Immortality Institute) forums, Seltzer and other members discuss life-extension strategies and the potential benefits of cognitive enhancers. Some members, Seltzer among them, use a drug called piracetam, which was first marketed by a Belgian pharmaceutical company in 1972 and in recent years has become available in the US from retailers that sell supplements. Although not approved for any use by the FDA, piracetam has been used experimentally on stroke patients - to little effect - and on patients with a rare neurological condition called progressive myoclonus epilepsy, for whom it proved helpful in alleviating muscle spasms. Data on piracetam's benefits for healthy people is virtually nonexistent, but many users believe that the drug increases blood flow to the brain.

If this is the case, this suggests some thoughtfulness about my use of nicotine: there are times when use of nicotine will not be helpful, but times where it will be helpful. I don’t know what makes the difference, but I can guess it relates to over-stimulation: on some nights during the experiment, I had difficult concentrating on n-backing because it was boring and I was thinking about the other things I was interested in or working on - in retrospect, I wonder if those instances were nicotine nights.

Including comprehensive lists of what to eat and what to avoid, a detailed quiz that will tell you where you are on the brain health spectrum, and 24 mouth-watering brain-boosting recipes that grow out of Dr. Mosconi’s own childhood in Italy, Brain Food gives us the ultimate plan for a healthy brain. Brain Food will appeal to anyone looking to improve memory, prevent cognitive decline, eliminate brain fog, lift depression, or just sharpen their edge.
Amongst the brain focus supplements that are currently available in the nootropic drug market, Modafinil is probably the most common focus drug used by people, and it’s actually touted to be the best nootropic available today.  It is a powerful cognitive enhancer that is great for boosting your overall alertness with least side effects.  However, to get your hands on this drug, you require a prescription.
Consider something as simple as a phone call. You hear the phone ring – your auditory capacity kicks in. Next, you decide whether to answer – decision-making comes into play. You reach for the phone – calling your motor skills to work. You answer – using your voice – all controlled by your brain, all done in mere moments, without conscious thought. Your brain works non-stop, consuming mental energy and physical resources.
This continued up to 1 AM, at which point I decided not to take a second armodafinil (why spend a second pill to gain what would likely be an unproductive set of 8 hours?) and finish up the experiment with some n-backing. My 5 rounds: 60/38/62/44/5024. This was surprising. Compare those scores with scores from several previous days: 39/42/44/40/20/28/36. I had estimated before the n-backing that my scores would be in the low-end of my usual performance (20-30%) since I had not slept for the past 41 hours, and instead, the lowest score was 38%. If one did not know the context, one might think I had discovered a good nootropic! Interesting evidence that armodafinil preserves at least one kind of mental performance.

Take quarter at midnight, another quarter at 2 AM. Night runs reasonably well once I remember to eat a lot of food (I finish a big editing task I had put off for weeks), but the apathy kicks in early around 4 AM so I gave up and watched Scott Pilgrim vs. the World, finishing around 6 AM. I then read until it’s time to go to a big shotgun club function, which occupies the rest of the morning and afternoon; I had nothing to do much of the time and napped very poorly on occasion. By the time we got back at 4 PM, the apathy was completely gone and I started some modafinil research with gusto (interrupted by going to see Puss in Boots). That night: Zeo recorded 8:30 of sleep, gap of about 1:50 in the recording, figure 10:10 total sleep; following night, 8:33; third night, 8:47; fourth, 8:20 (▇▁▁▁).

The amphetamine mix branded Adderall is terribly expensive to obtain even compared to modafinil, due to its tight regulation (a lower schedule than modafinil), popularity in college as a study drug, and reportedly moves by its manufacture to exploit its privileged position as a licensed amphetamine maker to extract more consumer surplus. I paid roughly $4 a pill but could have paid up to $10. Good stimulant hygiene involves recovery periods to avoid one’s body adapting to eliminate the stimulating effects, so even if Adderall was the answer to all my woes, I would not be using it more than 2 or 3 times a week. Assuming 50 uses a year (for specific projects, let’s say, and not ordinary aimless usage), that’s a cool $200 a year. My general belief was that Adderall would be too much of a stimulant for me, as I am amphetamine-naive and Adderall has a bad reputation for letting one waste time on unimportant things. We could say my prediction was 50% that Adderall would be useful and worth investigating further. The experiment was pretty simple: blind randomized pills, 10 placebo & 10 active. I took notes on how productive I was and the next day guessed whether it was placebo or Adderall before breaking the seal and finding out. I didn’t do any formal statistics for it, much less a power calculation, so let’s try to be conservative by penalizing the information quality heavily and assume it had 25%. So \frac{200 - 0}{\ln 1.05} \times 0.50 \times 0.25 = 512! The experiment probably used up no more than an hour or two total.
Colorful vegetables and fruits—such as leafy greens, peppers, beets, and berries—are high in carotenoids and anthocyanins, antioxidant pigments that provide their bright hues. “Antioxidants protect brain cell linings from the damage caused by free radicals, which are harmful molecules that cause inflammation and result from factors like a poor diet or smoking,” explains Janis Jibrin, RD, adjunct professor of nutrition at American University in Washington, D.C.
70 pairs is 140 blocks; we can drop to 36 pairs or 72 blocks if we accept a power of 0.5/50% chance of reaching significance. (Or we could economize by hoping that the effect size is not 3.5 but maybe twice the pessimistic guess; a d=0.5 at 50% power requires only 12 pairs of 24 blocks.) 70 pairs of blocks of 2 weeks, with 2 pills a day requires (70 \times 2) \times (2 \times 7) \times 2 = 3920 pills. I don’t even have that many empty pills! I have <500; 500 would supply 250 days, which would yield 18 2-week blocks which could give 9 pairs. 9 pairs would give me a power of:
Taking these drugs without a doctor’s supervision can be dangerous. There are interactions and contraindications that can cause serious problems. These drugs should not be used if you drink alcohol or take an antidepressant. (50) The possibility of adverse drug reactions should not be taken lightly. By some calculations, adverse drug reactions are now the fourth leading cause of death in the US. (51)
Cytisine is not known as a stimulant and I’m not addicted to nicotine, so why give it a try? Nicotine is one of the more effective stimulants available, and it’s odd how few nicotine analogues or nicotinic agonists there are available; nicotine has a few flaws like short half-life and increasing blood pressure, so I would be interested in a replacement. The nicotine metabolite cotinine, in the human studies available, looks intriguing and potentially better, but I have been unable to find a source for it. One of the few relevant drugs which I can obtain is cytisine, from Ceretropic, at 2x1.5mg doses. There are not many anecdotal reports on cytisine, but at least a few suggest somewhat comparable effects with nicotine, so I gave it a try.

My first dose on 1 March 2017, at the recommended 0.5ml/1.5mg was miserable, as I felt like I had the flu and had to nap for several hours before I felt well again, requiring 6h to return to normal; after waiting a month, I tried again, but after a week of daily dosing in May, I noticed no benefits; I tried increasing to 3x1.5mg but this immediately caused another afternoon crash/nap on 18 May. So I scrapped my cytisine. Oh well.
Is a powerful antioxidant that can help you deal with the brain aging process caused by the harmful effects of free radicals. This ingredient does an amazing job of protecting you against muscle catabolism and brain deterioration. In addition, it helps your blood vessels to expand, so all essential ingredients and oxygen are delivered to your brain. The traditional Chinese medicine has been using this herb to boost memory and mental performance.
I met Alex one evening last summer, at an appealingly scruffy bar in the New England city where he lives. Skinny and bearded, and wearing faded hipster jeans, he looked like the lead singer in an indie band. He was ingratiating and articulate, and smoked cigarettes with an ironic air of defiance. Alex was happy enough to talk about his frequent use of Adderall at Harvard, but he didn't want to see his name in print; he's involved with an internet start-up and worried that potential investors might disapprove of his habit.
Nootropics – sometimes called smart drugs – are compounds that enhance brain function. They’re becoming a popular way to give your mind an extra boost. According to one Telegraph report, up to 25% of students at leading UK universities have taken the prescription smart drug modafinil [1], and California tech startup employees are trying everything from Adderall to LSD to push their brains into a higher gear [2].
Legal Disclaimer Do Not exceed recommended dose for Colon Clean. Pregnant or nursing mothers, children under 18, and individuals with a known medical condition should consult a physician before using this or any dietary supplement. Be careful when using supplements with other supplements or prescription pharmaceuticals. This product is not intended to diagnose, treat, cure, or prevent any disease.
New psychiatric drugs have a way of creating markets for themselves. Disorders often become widely diagnosed after drugs come along that can alter a set of suboptimal behaviours. In this way Ritalin and Adderall helped make ADHD a household name, and advertisements for antidepressants have helped define shyness as a malady. If there's a pill that can clear up the wavering focus of sleep-deprived youth or mitigate the tip-of-the-tongue experience of middle age, then those rather ordinary states may come to be seen as syndromes.
Nootropics can also show signs of neuro-preservation and neuro-protection. These compounds directly affect the levels of brain chemicals associated with slowing down the aging process. Some nootropics could in an increase in the production of Nerve Growth Factor and Brain-Derived Neurotrophic Factor to stimulate the growth of neurons and neurites while slowing down the rate of damage as well.

Can brain enhancing pills actually improve memory? This is a common question and the answer varies, depending on the product you are considering. The top 25 brain enhancement supplements appear to produce results for many users. Research and scientific studies have demonstrated the brain boosting effects of nootropic ingredients in the best quality supplements. At Smart Pill Guide, you can read nootropics reviews and discover how to improve memory for better performance in school or at work.
I decided to try out day-time usage on 2 consecutive days, taking the 100mg at noon or 1 PM. On both days, I thought I did feel more energetic but nothing extraordinary (maybe not even as strong as the nicotine), and I had trouble falling asleep on Halloween, thinking about the meta-ethics essay I had been writing diligently on both days. Not a good use compared to staying up a night.
Modafinil, also known as Provigil, Modalert, and Alertec, was originally made and marketed for sleep disorders, and has been prescribed in the US for this reason since 1998. It was found only by chance to help with focus and concentration, and it is only approved for the treatment of narcolepsy, shift work sleep disorder, and obstructive sleep apnea.
The research literature, while copious, is messy and varied: methodologies and devices vary substantially, sample sizes are tiny, the study designs vary from paper to paper, metrics are sometimes comically limited (one study measured speed of finishing a RAPM IQ test but not scores), blinding is rare and unclear how successful, etc. Relevant papers include Chung et al 2012, Rojas & Gonzalez-Lima 2013, & Gonzalez-Lima & Barrett 2014. Another Longecity user ran a self-experiment, with some design advice from me, where he performed a few cognitive tests over several periods of LLLT usage (the blocks turned out to be ABBA), using his father and towels to try to blind himself as to condition. I analyzed his data, and his scores did seem to improve, but his scores improved so much in the last part of the self-experiment I found myself dubious as to what was going on - possibly a failure of randomness given too few blocks and an temporal exogenous factor in the last quarter which was responsible for the improvement.

Creatine is a substance that’s produced in the human body. It is initially produced in the kidneys, and the process is completed in the liver. It is then stored in the brain tissues and muscles, to support the energy demands of a human body. Athletes and bodybuilders take creatine supplements for relieving fatigue and increasing the recovery of the muscle tissues that are affected by vigorous physical activities. Apart from helping the tissues to recover faster, creatine also helps in enhancing the mental functions in sleep-deprived adults and it also improves the performance of difficult cognitive tasks.
Pre and Post-Natal Depression are both complex conditions that can have multifactorial underlying drivers, including genetic and environmental influences. These are currently poorly investigated and the gold standard of treatment is often medication to help stabilise mood. Whilst SSRIs and other types of antidepressants have proven to be helpful for many, they do not address potential causes or drivers of poor mental health and can often mask symptoms. Antidepressants are also not regularly recommended during pregnancy, which is why being more mindful of nutrition and lifestyle habits can be a safer option for you and your baby. There are some natural, evidence-based steps you can take to help support optimal mental wellbeing:
If you are a slow caffeine metabolizer and consume too much caffeine, you run the risk of mild to severe complications, such as cardiovascular disease. There’s also the sleep disruption problem of having too much caffeine left in your bloodstream late in the day as a result of a longer caffeine half-life, a problem not faced by fast caffeine metabolizers (it’s so unfair if you love your cup of joe, right?). In addition, fast caffeine metabolizers actually run a reduced risk of cardiovascular complications if they consume at least one cup of coffee per day. While anyone can be a slow caffeine metabolizer, there are certain ethnic backgrounds that are indeed associated with slower and faster caffeine metabolisms. For example, it’s known that people with Asian and African ethnic backgrounds generally have slower rates of caffeine metabolism. To find out if you’re a fast or slow caffeine metabolizer, you can have a relatively inexpensive salivary genetic test performed by a company like 23andme and then use the online dashboard to jump straight to your CYP1A2 gene. When you’re there, you type into the search bar “rs762551”. If your rs762551 SNP variant is AA, then you’re a fast caffeine metabolizer, but if your variant is AC or CC, you’re a slow caffeine metabolizer. Fortunately, many genetic testing companies will now simply report directly on your results whether you’re a slow or fast metabolizer, without you needing to go through the SNP searching trouble.
NGF may sound intriguing, but the price is a dealbreaker: at suggested doses of 1-100μg (NGF dosing in humans for benefits is, shall we say, not an exact science), and a cost from sketchy suppliers of $1210/100μg/$470/500μg/$750/1000μg/$1000/1000μg/$1030/1000μg/$235/20μg. (Levi-Montalcini was presumably able to divert some of her lab’s production.) A year’s supply then would be comically expensive: at the lowest doses of 1-10μg using the cheapest sellers (for something one is dumping into one’s eyes?), it could cost anywhere up to $10,000.

In addition to this, privilege also plays an important role in this epidemic. "Not everyone has access to eat healthily", she mentions. In fact, she recalls an anecdote in which a supermarket owner noticed how people living off food stamps rarely use them to buy fruits and vegetables. Curious about this trend, the owner approached someone with food stamps, to which she admitted she didn't buy them because she didn't know the price prior to weighing them and felt ashamed of asking. His solution? Pre-cutting and packaging fruits in order to make them more accessible to those with lower incomes. 
This is why it was so refreshing to stumble across Dr. Lisa Mosconi's new book "Brain Food: The Surprising Power of Eating for Cognitive Power" . "Our brains aren't keeping up with the historical change in dietary consumptions", says Dr. Lisa. And it's quite evident in her book when she does a historical overview and draws an important relationship between what our ancestors were eating and the concept of longevity. Her contribution to the fascinating new world of "neuro-nutrition" differs drastically from the diet culture we are all so used to and can help us understand why including (and excluding) certain foods, will actually boost our brain health. 

Fortunately for me, the FDA decided Smart Powder’s advertising was too explicit and ordered its piracetam sales stopped; I was equivocal at the previous price point, but then I saw that between the bulk discount and the fire-sale coupon, 3kg was only $99.99 (shipping was amortized over that, the choline, caffeine, and tryptophan). So I ordered in September 2010. As well, I had decided to cap my own pills, eliminating the inconvenience and bad taste. 3kg goes a very long way so I am nowhere close to running out of my pills; there is nothing to report since, as the pills are simply part of my daily routine.
Reason: Besides keeping cells intact, this membrane performs vital functions. These actions include moving nutrients into cells and pumping waste products out of them. Investigators in one study determined that phosphatidyl serine shaved 12 years off the normal expected decline. This result was present in specific aspects of memory performance. Phosphatidyl serine is shown in studies to boost cognitive function. This occurs by increasing communication between brain cells. Those who took 100 mg of phosphatidyl serine three times a day, with meals for 12 weeks scored 30% higher on memory and learning tests.
Ampakines are structurally derived from a popular nootropic called “aniracetam”. Their basic function is to activate AMPA glutamate receptors (AMPARs). Glutamate (a neurotransmitter) is the primary mediator of excitatory synaptic transmission in mammalian brains, which makes it crucial for synaptic plasticity (the adaptation of synapses, the space between neurons across which information is sent), learning and memory, so when you activate or stimulate glutamate receptors, you can trigger many of these functions. AMPARs are distributed across the central nervous system and are stimulated by incoming glutamate to begin the neuroenhancing benefits they’re often used for. But it is possible to have too much glutamate activity. When excess glutamate is produced, accumulates and binds to AMPARs, the result is excitotoxicity, which is a state of cell death (in the case of the central nervous system and your brain, neuron death) resulting from the toxic levels of excitatory amino acids. Excitotoxicity is believed to play a major role in the development of various degenerative neurological conditions such as schizophrenia, delirium and dementia.
And if you obtain your vitamin C from a multivitamin, you receive other key nutrients that many studies over the years have linked to healthy brain function, including beta carotene, iron, zinc, B12 and folic acid. In the June 1999 issue of the Journal of Biology and Psychiatry, for instance, researchers at Sweden's Gotenborg University reported that older people were more likely to score poorly on word memory tests if they had low levels of folic acid.
The realm of natural nootropics is also accompanied by a family of synthetic nootropics called racetams, most notably piracetam and aniracetam. Piracetam is known to directly enhance learning, memory and attention and, with no observed adverse side effects, can restore cognitive performance in patients who have suffered cranial trauma, inflammation, strokes and ischemic complications following coronary bypass surgery. It can also improve symptoms of delirium and reduce depression and anxiety. In adults, the standard dose of piracetam ranges from 1,200 to 4,800 mg, often broken up into three smaller doses throughout the day. Aniracetam has been shown to concentration-dependently counteract cell death induced by excitotoxicity caused by glutamate, resulting in an overall neuroprotective effect. While you may not be shoveling mouthfuls of glutamate down your hatch or eating cartonsful of MSG-containing Chinese food each night, the same mechanism of action can help protect your brain from excitotoxicity or inflammation caused by other central nervous system irritants, such as toxins, chemicals, herbicides, pesticides, rancid oils, etc. Effective doses of aniracetam range from a single 400 mg dose to two doses per day between 500 and 750 mg, taken with meals.

So the chi-squared believes there is a statistically-significant difference, the two-sample test disagrees, and the binomial also disagrees. Since I regarded it as a dubious theory, can’t see a difference, and the binomial seems like the most appropriate test, I conclude that several months of 1mg iodine did not change my eye color. (As a final test, when I posted the results on the Longecity forum where people were claiming the eye color change, I swapped the labels on the photos to see if anyone would claim something along the lines when I look at the photos, I can see a difference!. I thought someone might do that, which would be a damning demonstration of their biases & wishful thinking, but no one did.)

Colorful vegetables and fruits—such as leafy greens, peppers, beets, and berries—are high in carotenoids and anthocyanins, antioxidant pigments that provide their bright hues. “Antioxidants protect brain cell linings from the damage caused by free radicals, which are harmful molecules that cause inflammation and result from factors like a poor diet or smoking,” explains Janis Jibrin, RD, adjunct professor of nutrition at American University in Washington, D.C.
For 2 weeks, upon awakening I took close-up photographs of my right eye. Then I ordered two jars of Life-Extension Sea-Iodine (60x1mg) (1mg being an apparently safe dose), and when it arrived on 10 September 2012, I stopped the photography and began taking 1 iodine pill every other day. I noticed no ill effects (or benefits) after a few weeks and upped the dose to 1 pill daily. After the first jar of 60 pills was used up, I switched to the second jar, and began photography as before for 2 weeks. The photographs were uploaded, cropped by hand in Gimp, and shrunk to more reasonable dimensions; both sets are available in a Zip file.

Some work has been done on estimating the value of IQ, both as net benefits to the possessor (including all zero-sum or negative-sum aspects) and as net positive externalities to the rest of society. The estimates are substantial: in the thousands of dollars per IQ point. But since increasing IQ post-childhood is almost impossible barring disease or similar deficits, and even increasing childhood IQs is very challenging, much of these estimates are merely correlations or regressions, and the experimental childhood estimates must be weakened considerably for any adult - since so much time and so many opportunities have been lost. A wild guess: $1000 net present value per IQ point. The range for severely deficient children was 10-15 points, so any normal (somewhat deficient) adult gain must be much smaller and consistent with Fitzgerald 2012’s ceiling on possible effect sizes (small).
Like everything else in your body, the brain cannot work without energy. The ability to concentrate and focus comes from an adequate, steady supply of energy - in the form of glucose in our blood to the brain. Achieve this by choosing wholegrains with a low-GI, which release glucose slowly into the bloodstream, keeping you mentally alert throughout the day. Opt for 'brown' wholegrain cereals, granary bread, rice and pasta.
I take my piracetam in the form of capped pills consisting (in descending order) of piracetam, choline bitartrate, anhydrous caffeine, and l-tyrosine. On 8 December 2012, I happened to run out of them and couldn’t fetch more from my stock until 27 December. This forms a sort of (non-randomized, non-blind) short natural experiment: did my daily 1-5 mood/productivity ratings fall during 8-27 December compared to November 2012 & January 2013? The graphed data29 suggests to me a decline:
Brain focus pills largely contain chemical components like L-theanine which is naturally found in green and black tea. It’s associated with enhancing alertness, cognition, relaxation, arousal, and reducing anxiety to a large extent.  Theanine is an amino and glutamic acid that has been proven to be a safe psychoactive substance. There are studies that suggest that this compound influences, the expression in the genes present in the brain which is responsible for aggression, fear and memory. This, in turn, helps in balancing the behavioural responses to stress and also helps in improving specific conditions, like Post Traumatic Stress Disorder (PTSD).
I met Alex one evening last summer, at an appealingly scruffy bar in the New England city where he lives. Skinny and bearded, and wearing faded hipster jeans, he looked like the lead singer in an indie band. He was ingratiating and articulate, and smoked cigarettes with an ironic air of defiance. Alex was happy enough to talk about his frequent use of Adderall at Harvard, but he didn't want to see his name in print; he's involved with an internet start-up and worried that potential investors might disapprove of his habit.
Please take care when you’re out there on the web or in the world shopping for something to help that in progress novel or craft project of yours along. Take all care when planning on taking anything, be it a nootropic, smart drug, or brain enhancer, and do your research before buying. Make sure your so-called ‘best brain pill’ really is the best brain pill for you.
…researchers have added a new layer to the smart pill conversation. Adderall, they’ve found, makes you think you’re doing better than you actually are….Those subjects who had been given Adderall were significantly more likely to report that the pill had caused them to do a better job….But the results of the new University of Pennsylvania study, funded by the U.S. Navy and not yet published but presented at the annual Society for Neuroscience conference last month, are consistent with much of the existing research. As a group, no overall statistically-significant improvement or impairment was seen as a result of taking Adderall. The research team tested 47 subjects, all in their 20s, all without a diagnosis of ADHD, on a variety of cognitive functions, from working memory-how much information they could keep in mind and manipulate-to raw intelligence, to memories for specific events and faces….The last question they asked their subjects was: How and how much did the pill influence your performance on today’s tests? Those subjects who had been given Adderall were significantly more likely to report that the pill had caused them to do a better job on the tasks they’d been given, even though their performance did not show an improvement over that of those who had taken the placebo. According to Irena Ilieva…it’s the first time since the 1960s that a study on the effects of amphetamine, a close cousin of Adderall, has asked how subjects perceive the effect of the drug on their performance.
Systematic reviews and meta-analyses of clinical human research using low doses of certain central nervous system stimulants found enhanced cognition in healthy people.[21][22][23] In particular, the classes of stimulants that demonstrate cognition-enhancing effects in humans act as direct agonists or indirect agonists of dopamine receptor D1, adrenoceptor A2, or both types of receptor in the prefrontal cortex.[21][22][24][25] Relatively high doses of stimulants cause cognitive deficits.[24][25]