Friday, January 02, 2009

Caffeine or Nap: Which Helps Memory?

Caffeine gets our brain pumped up. We are more alert and perhaps should remember things better. Naps have recently been found to help the memory consolidation process. Until now, nobody has made a direct comparison of these two factors in the same people under identical conditions. But Sara Mednick and her colleagues at the University of California, San Diego, now report some helpful findings.
They tested caffeine in a single dose of 200 mg (roughly equivalent to 2-3 cups of coffee) and compared with an episode of napping (60-90 min) or placebo on the effects on performance on three types of memory tasks. For verbal memory, they tested recall and recognition memory of word lists 7 hours after learning, with an intervening nap, caffeine dose, or placebo. In addition, they conducted memory tests for a finger tap and texture discrimination task.They also conducted short-term memory on a different set of words after the first experiment.
Compared with either caffeine or placebo, naps were more effective in the word recall test, both in the consolidation test and in the short-term memory condition. Caffeine actually impaired word recall in the short-term memory task, even though the caffeine had been given some seven hours earlier. Naps also improved recognition memory in the consolidation test and recall of the texture discrimination learning. For the finger-tap learning, naps were ineffective and caffeine markedly impaired performance. The caffeine group did feel less sleepy in the late afternoon immediately prior to the memory testing, but that did not help their memory performance.
What I take from this is that the morning coffee may help you awaken, but don’t count on it to improve your memory. Other research does show that caffeine enhances mood and alertness, reaction times and speed, but don’t count on it to help your memory for things you learn that day. Note to students: all-night study sessions are a bad idea for lots of reasons and probably made much worse by drinking lots of coffee. Note to bosses: letting workers take an afternoon snooze might be a good idea.

Mednick, S. C. et al. 2008. Comparing the benefits of caffeine, naps, and placebo on verb al, motor and perceptual memory. Behavioural Brain Research. 193: 79-86.


  1. Caffeine may interfere with CA2+ processes in the brain which are implicated in generating new synapses or changing synaptic structure.

    This might be why it has a disruptive impact on memory.

  2. Very interesting.

    As a memory athlete, would it be better to disclaim any coffe at a championship?

  3. It is very interesting.If i want to remember more of what i have learned i should take a Nap.
    But i think test is a little unfair to Caffeine.Caffeine maybe not so good at consolidating memory as a Nap. But in a Nap you can learn nothing. I think the people who continuous to learn the same word list in the time some others taking Naps can do better in the recall Test. So the real problem is "How much" will Caffeine reduce memory consolidation relative to Nap and "How much" can people learn with Caffeine.
    Another questions is weather the skills or lessons i learn in the night with cups of coffee are easier to loss. If it is so, then the students have another reason to abandon night coffees.

  4. Anonymous2:34 PM

    this test isn't right because its says that the caffiene was taken 7 hours before and then the test is given. Caffiene boost the brain so after you learn everything, sleeping helps you to remember everything, and then caffience boost your brain to be productive and perform better because you already know everything you just need the energy to perform better. However caffiene is like sugar so 7 hours later means that the effect of it is gone and your back to being worn out and tired. I know this cuase this is what i've been doing since high school and im a freshman in college now and I still find it very effective:)


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