By: Dan Lerner & Dr. Alan Schlechter
Image: The Yerkes-Dodson Law (YDL)
How much stress is good for you?
In 1908, Robert Mearns Yerkes and John Dillingham Dodson designed an experiment that would begin to tackle the question, “How much stress is good for you?”
The researchers tracked mice to see how stress would affect their ability to learn. Simple—yet painful, because how do you stress out mice? Read the rest of this entry »
By: Dr. Pascale Michelon
A few eternal questions:
– Is caffeine good for the brain?
– Does it boost cognitive functions?
– Does it protect against dementia?
There is little doubt that drinking that morning cup of coffee will likely increase alertness, but the main questions that research is trying to answer go beyond that. Basically: is there a sustained, lifetime, benefit or harm from drinking coffee regularly?
The answer, so far, contains good news and bad news. The good news for coffee drinkers is that most of the long-term results are directionally more positive than negative, so no clear harm seems to occur. The bad news is that it is not clear so far whether caffeine has beneficial effects on general brain functions, either short-term or long-term (aged-related decline or risks of dementia).
It is important to note that many of the studies showing an effect of coffee consumption on brain functions or risks of dementia report a correlation or association (they are not randomized clinical trials). As you know, correlation doesn’t prove causation: coffee drinkers may seem to do well in a number in these long-term studies, but there may be other reasons why coffee drinkers do better.
Q: How does caffeine affect my brain?
A: Caffeine is a stimulant.
It belongs to a chemical group called xanthine. Adenosine is a naturally occurring xanthine in the brain that slows down the activity of brain cells (neurons). To a neuron, caffeine looks like adenosine. It is therefore used by some neurons in place of adenosine. The result is that these neurons speed up instead of slowing down.
This increased neuronal activity triggers the release of the adrenaline hormone, which will affect your body Read the rest of this entry »