Why getting out of breath ? I read everywhere that *aerobic* exercise
was the key.
> drink some stimulant drink with caffeine
I fear this isn't true:
Pregnant women should avoid caffeine too:
I'd love to believe caffeine is good for my brain, but it doesn't seem
to be true.
I agree with everything else.
That's what I'm wondering too. Also, according to some authors,
caffeine can have protective effects against Alzeihmer or Parkinson
It's interesting to note that the caffeine concentration used in this
study isn't as "low" as they claim it to be. 0.3 g/L means roughly 1.5
gram in total for a human, while your average brewed coffee cup
contains around 150 mg. Even if drinking 4 or 5 cups a day, you have
to consider that caffeine's half-life is 4 to 6 hours which means it
is nearly impossible to reach that blood concentration. It would be
interesting to know if any effect were noticeable below that
concentration, or if they didn't make the experiment.
I have put the PDF up for the Group.
"In this study, we chose a low dose of caffeine (0.3 g/L) for two main
reasons: First, it leads to a plasma level of caffeine representative
of regular daily human consumption; and second, in a model of neonatal
ischemia, this low dose of 0.3 g/L was more protective than a higher
dose, 0.8 g/L . However, it would be of interest to extend the
present study to other doses of caffeine."
If you look at page 2 (page 3 is just the changes in cell biology,
which has an unclear relation to what we actually care about -
performance), the performance measurements differ. The 'latency' - how
long it takes the rats to get to the platform - has a small gap by
week 4 between uncaffeinated and caffeinated rats. But it's a very
small gap, and doesn't seem too interesting.
"Repeated measurements revealed that caffeine-fed rats were slower to
find the hidden platform than control rats during the initial testing
period, although the groups were similar at the later period (Fig.
The next test seems to be 'how long the rats spent looking for the
hidden platform in the water where it was last time (lo those many
weeks ago)', and the difference there is quite substantial:
"To test the effect of caffeine on long-term memory we gave rats a
probe trial at 1, 2, and 3 weeks after training. There was no
performance difference between the caffeine-fed and the control groups
on the week 1 probe trial. However, caffeine-fed rats performed
significantly worse than control rats on the week 2 and week 3 probe
trials and spent only a little more time than that expected by chance
in the target quadrant (Fig. 1B)."
There is no overlap between the normal and caffeinated groups, and the
peak mean performance of the normals is about 20; the final mean of
the normals is about 15; and the caffeinated final mean is about 5.
One thing to note is that there are three performance tests here: 1A)
finding the hidden platform in the first place; 1B) time spent looking
in the right place; 1C) finding a visible platform. The differences
are neglible on 1A and 1C, but noticeable on 1B. 1B is, I think, the
task closest to trying to remember something ab initio, and the one we
should care about.
Is this relevant for us? Haven't there been many studies showing
caffeine aids intelligence and memory? The authors try to address
"Extensive studies concerning the effects of caffeine on memory have
been conducted. Most of these studies have suggested that caffeine
improves memory [1,2,11,12]. However, the present study showed that
long-term consumption of caffeine could impair memory (Fig. 1). One of
the differences between the present study and previous studies is that
most of the previous studies were focused on the acute effects of
caffeine. Acute administration of caffeine decreased the threshold for
convulsants [13,14]. In contrast, chronic administration of caffeine
increased it [15,16]. Moreover, acute administration of caffeine
worsened ischemia-induced damage , however, chronic administration
of caffeine reduced it [18,19]."
 W.J. Riedel, J. Jolles, Cognition enhancers in age-related
cognitive decline, Drugs Aging 8 (1996) 245–274.
 W. Riedel, E. Hogervorst, R. Leboux, F. Verhey, H. van Praag, J.
Jolles, Caffeine attenuates scopolamine-induced memory impairment in
humans, Psychopharmacology (Berl) 122 (1995) 158–168.
 M.S. Gevaerd, R.N. Takahashi, R. Silveira, C. Da Cunha, Caffeine
reverses the memory disruption induced by intra-nigral MPTPinjection
in rats, Brain Res. Bull. 55 (2001) 101–106.
 R.D. Prediger, F.A. Pamplona, D. Fernandes, R.N. Takahashi,
Caffeine improves spatial learning deficits in an animal model of
attention deficit hyperactivity disorder (ADHD)—the spontaneously
hypertensive rat (SHR), Int. J. Neuropsychopharmacol. 8 (2005)
While looking these up, I ran into another paper: 'Effects of caffeine
on learning and memory in rats tested in the Morris water maze' (also
"We studied some of the characteristics of the improving effect of the
non-specific adenosine receptor antagonist, caffeine, using an animal
model of learning and memory. Groups of 12 adult male Wistar rats
receiving caffeine (0.3-30 mg/kg, ip, in 0.1 ml/100 g body weight)
administered 30 min before training, immediately after training, or 30
min before the test session were tested in the spatial version of the
Morris water maze task. Post-training administration of caffeine
improved memory retention at the doses of 0.3-10 mg/kg (the rats swam
up to 600 cm less to find the platform in the test session, P£0.05)
but not at the dose of 30 mg/kg. Pre-test caffeine administration also
caused a small increase in memory retrieval (the escape path of the
rats was up to 500 cm shorter, P£0.05). In contrast, pre-training
caffeine administration did not alter the performance of the animals
either in the training or in the test session. These data provide
evidence that caffeine improves memory retention but not memory
acquisition, explaining some discrepancies among reports in the
This would seem to work well with the first paper, and leads to a
relatively simple piece of advice: caffeine hinders learning*, but
helps remembering. So avoid your coffee when you're studying something
the first time, but feel free to imbibe before a test or a review
session. (This would be good for a FAQ.)
* also, learning takes place over a while. The discrepancy on the
second test with Han's caffeinated/non-caffeinated mice takes place in
the *first* week: you will notice that the normals' score shoots up
until it peaks in week 2, while the caffeinated rats' score descends.
But after that, the lines are parallel downwards.
Reading the actual study, I realized that 0.3 g/L was the
concentration of caffeine in the drinking water the rats were given,
*not* plasma or blood concentration as I thought.
This is pretty scary stuff.
And incidentally I've uploaded in the past a number of other files,
such as the three main n-back papers, so if you haven't read them
now's your chance.
That said, I wish I knew more about the 'average daily' caffeine
level. I drink 1 or 2 mugs of green tea a day - is that up to this
level? Does the effect decrease proportionately? etc. As it is, all I
feel comfortable inferring is 'don't use caffeine while studying new
I would say it does model human consumption reasonably well. Caffeine
is in all sorts of beverages; soda in particular is often consumed
like that - early in the day, late in the day, when one is thirsty,
People drink coffee when they get up in the morning, they drink coffee
when they get tired by lunch, they have some coffee to prep them up
mid-afternoon; then perhaps they go home or out and have some soda, or
maybe some tea with their dinner sushi, and so on. Caffeine is too
ingrained in a modern Western lifestyle for me to be as sanguine and
dismissive as you are.
If the rats are badly dehydrated and insomniacs to boot, then wouldn't
we expect to see their physical - and not just their mental -
performance deteriorate significantly? Remember that in the second
latency test, when the rats could see the platform and learning/memory
has no role, the two groups had minimal difference:
"Next, we performed a cue version of the MWM test 4 weeks after
drinking caffeinated water. The spatial version of theMWMtest is
dependent on the hippocampus;however, the cue version of the MWM test
is dependent on the striatum, not the hippocampus.As in the spatial
task, both groups learned the task gradually. Repeated measurements
showed no significant difference between the two groups (Fig. 1C)."
"(C) There was no significant difference between caffeine-fed and
control rats in a cue training test."
> On Apr 1, 1:44 pm, Gwern Branwen <gwe...@gmail.com> wrote:
> > This question is somewhat covered by my
> > FAQ:http://community.haskell.org/~gwern/wiki/N-backFAQ.page
Thanks! Very informative.
That first link is useful: not only is it another datapoint for the IQ
tests, it also links to one I haven't seen before - and even better,
one which varies the questions!