Dementia - Page 35 of 35

Hidden Caves in the Brain Open Up During Sleep to Wash Away Toxins

“Hidden caves” that open up in the brain may help explain sleep’s amazing restorative powers.

A new study published in the prestigious journal, Science, has found that the brain may wash away toxins built up over the day during sleep.

The research discovered “hidden caves” inside the brain, which open up during sleep, allowing cerebrospinal fluid (CSF) to flush out potential neurotoxins, like β-amyloid, which has been associated with Alzheimer’s disease.

To reach their discovery, researchers injected mice’s brains with a dye and monitored the flow while they were awake, asleep and anaesthetised (Xie et al., 2013).

One of the study’s authors, Dr Maiken Nedergaard, explained the results:

“We were surprised by how little flow there was into the brain when the mice were awake. It suggested that the space between brain cells changed greatly between conscious and unconscious states.”

For a long time the real physiological purpose of sleep has remained a mystery.

We know that lack of sleep causes all kinds of psychological problems like poor learning, decision-making and so on.

We also know that animals that are chronically deprived of sleep will eventually die: flies or rodents in days to weeks, humans within months or years.

Everyone who has ever enjoyed a blissfully good night’s sleep knows just how restorative it can be, but the actual physiological process wasn’t clear.

This study, though, suggests that the flushing out of toxins by the CSF may be central to sleep’s wondrous powers.

The interstitial spaces in the mouse’s brain took up only 14% of the brain’s volume while it was awake. Yet, while it slept, this increased by almost two-thirds to take up fully 23% of the brain’s total volume.

The difference might seem slight, but the actual physiological effects are profound.

During the day, the CSF mostly covers the surface of the brain. During sleep, though, the CSF is able to move deep inside.

The effect is that potential neurotoxins, like β-amyloid, are cleared twice as fast during sleep as during waking.

The results of this study–if they hold in humans–may help to explain why many neurological diseases, like strokes and dementia, are associated with problems sleeping.

It could be that lack of sleep, and restriction of the brain’s cleaning system, may cause toxic metabolites to building up, leading to long-term damage.

→ Related: 10 Sleep Deprivation Effects.

Image credit: HaoJan Chang

10 Superb Psychological Advantages of Learning Another Language

Learning another language can promote brain growth, stave off dementia, boost memory, improve attention and more…

Benefits of learning a second language include brain growth, staving off dementia, boosting memory, improving attention and more…

“To have another language is to possess a second soul.” –Charlemagne

People used to think that learning two languages created confusion in the mind.

Far better, it was thought, to get one right than bother with two.

An even more extreme and absurd view was that learning two languages caused a kind of schizophrenia or dual personality.

Some studies did seem to back up the idea that learning two languages could be problematic; early researchers noted that bilingual people tended to have smaller vocabularies and slower access to words.

But these myths and minor disadvantages have now been overshadowed by a wave of new research showing the incredible psychological benefits of learning a second language. And these extend way beyond being able to order a cup of coffee abroad or ask directions to your hotel.

1.Brain growth

The fact that language centres in the brain actually grow is one of the major benefits of learning a second language.

The better you learn, the more those vital areas of the brain grow (Mårtensson et al., 2012).

2. Stave off dementia

Bilingualism delays Alzheimer’s disease in susceptible people by as much as five years (Craik et al., 2010). Seems incredible, but the studies are continuing to support this result.

To put this in context: the effect on dementia of learning another language is much greater than anything achievable with the latest drugs.

3. Hear language better

Being bilingual can lead to improved listening skills, since the brain has to work harder to distinguish different types of sounds in two or more languages (Krizman et al., 2012).

4. Become more language sensitive

Infants in bilingual households can distinguish languages they’ve never even heard before (Werker & Sebastian-Galles, 2011).

Just being exposed to the different sounds in, for example, Spanish and Catalan, helps them tell the difference between English and French is another of the benefits of learning a second language.

5. Boost your memory

Babies brought up in a bilingual environment have stronger working memories than those brought up with only one language (Morales et al., 2013).

This means they are better at mental calculation, reading and many other vital skills.

6. Better multi-tasking

Bilingual people can switch from one task to another more quickly.

They show more cognitive flexibility and find it easier to adapt to unexpected circumstances (Gold et al., 2013)

7. Increased attention

Bilinguals have stronger control over their attention and are better able to limit distractions (Bialystok & Craik, 2010).

8. Double the activation

Cognitive boosts, like improved attention and better multi-tasking, may come because bilingual people have both languages activated at the same time, and must continually monitor which one is appropriate (Francis, 1999).

All that switching back and forth confers the benefits of learning a second language.

9. New ways of seeing

Learning a new language can literally change the way you see the world.

Learning Japanese, for example, which has basic terms for light and dark blue, may help you perceive the colour in different ways (Athanasopoulos et al., 2010).

10. Improve your first language

Since learning a second language draws your attention to the abstract rules and structure of language, it can make you better at your first language.

As Geoffrey Willans said: “You can never understand one language until you understand at least two.”

Benefits of learning a second language

These ten are all quite apart from the benefits of immersing yourself in another culture, and of seeing your own culture from the perspective of another.

All told, you may well get something like ‘a second soul’ from learning another language.

[Note: some of these studies relate specifically to those who have learned two languages from very early on, but may also be relevant to new language learners.]

Image credit: Michael Davis-Burchat

Misleading Reporting of Alzheimer’s and Conscientiousness Research

There is some classic misinformation in the reporting of a new Alzheimer’s study on the BBC News website.

There is some classic misinformation in the reporting of a new Alzheimer’s study on the BBC News website. Entitled ‘Discipline’ may beat Alzheimer’s the first part of the story suggests the personality variable of conscientiousness might protect against developing Alzheimer’s. The link from the homepage states boldly, “Being conscientious may ward off Alzheimer’s.” In fact this line is a far cry from the study which merely finds a correlation between high conscientiousness and lower levels of Alzheimer’s.

Continue reading “Misleading Reporting of Alzheimer’s and Conscientiousness Research”

Brain Cells Matured in Lab

“US scientists say they have duplicated the generation of new adult brain cells in the lab in a controlled way. It is hoped the technique, tested so far on animal cells, will eventually allow scientists to produce a limitless supply of a person’s own brain cells.”
“It is not the first time that immature stem cells have been manipulated in the laboratory to become brain cells. But the researchers say nobody else has replicated the process of cell maturation that goes on in the brain in such complete and close step-by-step detail before.”

The hope is that the cells can be used in the treatment of dementia, Parkinson’s disease and epilespsy.
BBC News