The negative impact of stress on our working memory can be the same as this after “physical” damages.
Life experiences change the length and complexity of our brain cells. Chronic daily stress affect neurons in two different areas of the rat brain.
What does the chronic stress cause?
Decreased performance in tasks that require attention. Working memory is” angry”. Stressed rats need more time to catch on to a new pattern in an experimental task.
The prefrontal cortex is typically involved in working memory. And sure enough, neurons in the stressed rats in the medial prefrontal cortex were shorter and had less branching than those in the control rats.
As an effect – decreased performance of working memory has been observed after lesions, brain damages.
So, suppose we allow ourselves to be under prolonged stress. The negative impact of stress on our working memory can be the same as this after “physical” damages.
Is any other area of the brain affected by stress?
What is interesting, neurons in orbital frontal cortex in stressed rats were longer and more branched! This area of the brain is responsible for modifying behaviour.
Because of the negative impact on prefrontal cortex, prolonged stress can lead to impulsive,
even violent behaviour, increased anxiety, depression, alcohol and drug abuse etc.
So, take it easy. We don't want impulsive, depressive or angry abusers 
Read more:
http://newswire.rockefeller.edu/index.php?page=engine&id=545
Powerful reasons why children benefit from music education.
Playing music improve children’s reading and verbal skills.
Directly music increase level of concentration, memory and self-expression.
What else?
Socializing. Children learned to like each other. They become less stressed and enjoyed school more.
How about spacial learning, thinking?
Playing music builds or modifies neural pathways related to spatial reasoning tasks.
Notice that these are crucial for math, science, chess, etc.
There were studies comparing 4 groups of children.
Theses having: computer lessons, singing lessons, playing lessons (keyboard).
And the last group had nothing like these.
Results:
what really interesting the children who had had the MUSIC classes scored significantly higher – up to 35% – than the children who did nothing additional and what surprisingly also 35% higher than children who had computer classes o.[1]
(notice, that these studies were made before 1993).
[1] E W Weber, M Spychiger and J-L Patry, Musik macht Schule. Biografie und Ergebnisse eines Schulversuchs mit erweitertemMusikuntericcht. Padagogik in der Blauen Eule, Bd17. 1993.
Playing music
Training can improve fluid inteligence.
Most IQ tests attempt to measure two types of intelligence–crystallized and fluid intelligence. Crystallized intelligence draws on existing skills, knowledge and experiences to solve problems by accessing information from long-term memory.
Fluid intelligence, on the other hand, draws on the ability to understand relationships between various concepts, independent of any previous knowledge or skills, to solve new problems. The research shows that this part of intelligence can be improved through memory training.
Why does the training can improve our fluid intelligence?
The authors find some features of fluid intelligence relevant to the ability to solve new tasks.
This ability includes ignoring irrelevant items, monitoring ongoing performance, managing two tasks simultaneously and connecting related items to one another in space and time. The more times you are faced with new problems the stronger the above aspects you have.
The authors don’t know how long the improvement will last after giving up training.
Read more:
http://www.nytimes.com/2008/04/29/health/research/29brai.html
Individuals do differ in capaticy of working memory
What do working memory do (in general)?
When we jump (with our eyes) from one object to another some fuzzy images are generated. The brain gets couple of snapshots of about a quarter-second. There is a big role for working memory, which retains snapshots so they can be linked in a film. Working memory works as a high-resolution camera, keeping couple of features in hight detail. It also deals with objects that are temporarily blocked from looking at. Do we have different working memories? Yes. Individuals differ in the number of features that can be stored at once and in the resolution of each single feature. How about the resolution of working memory? In general WM is constant during your life. Not surprisingly higher levels of "fluid intelligence” have people with bigger capacity of working memory. Do we have working memory from birth? Not exactly. Between the age of 6 and 10 months we rapidly develop adult-like working memory. (http://www.news.ucdavis.edu/search/news_detail.lasso?id=8592)
Brains activation during a memory task.
