Cognitive reserve & late-life dementia

Changing perspectives regarding late-life dementia
Majid Fotuhi, Vladimir Hachinski & Peter J. Whitehouse
Nature Reviews Neurology 5, 649-658 (December 2009)

Individuals over 80 years of age represent the most rapidly growing segment of the population, and late-life dementia has become a major public health concern worldwide.
Development of effective preventive and treatment strategies for late-life dementia relies on a deep understanding of all the processes involved. In the centuries since the Greek philosopher Pythagoras described the inevitable loss of higher cognitive functions with advanced age, various theories regarding the potential culprits have dominated the field, ranging from demonic possession, through ‘hardening of blood vessels’, to Alzheimer disease (AD).
Recent studies suggest that atrophy in the cortex and hippocampus—now considered to be the best determinant of cognitive decline with aging—results from a combination of AD pathology, inflammation, Lewy bodies, and vascular lesions.
A specific constellation of genetic and environmental factors (including apolipoprotein E genotype, obesity, diabetes, hypertension, head trauma, systemic illnesses, and obstructive sleep apnea) contributes to late-life brain atrophy and dementia in each individual.
Only a small percentage of people beyond the age of 80 years have ‘pure AD’ or ‘pure vascular dementia’.
These concepts, formulated as the dynamic polygon hypothesis, have major implications for clinical trials, as any given drug might not be ideal for all elderly people with dementia.

You don’t need cognitive stimulation

John Zeisel on ‘hopeful aging’
Jul 7, 2013

Creative means discovery, creative means learning, creative means invention, creative means comprehension.
We’re always in search of understanding.

You can’t learn, be innovative, discover, be creative with banality.
Playing bingo isn’t going to cut it. It’s not interesting enough.
Looking at a Matisse and saying, “What is this painting about?” — that’s interesting enough.

Sudoku, crossword puzzles — mental exercise is not what I’m talking about.
It doesn’t do it. The term that’s used for those is ‘cognitive stimulation.’
You don’t need cognitive stimulation. You have to have meaning in your life. If it’s meaningful, it will stimulate you.

Is there anything else we can do to help our brains age well?
The basic three are sleep, diet and exercise.

The second level of intervention is stress reduction and creative endeavors: the arts, learning. The learning can be anything. It can be based on aptitudes and skills you already have, or you can also learn new skills. All kinds of learning are as essential as stress reduction.

The biggest misconception is that people with dementia can’t learn.
There are four learning systems in the brain.
One is called episodic learning: there’s an event in my life and I remember what happened.
The second is semantic learning, like learning a word out of context.
Then there’s emotional learning, which revolves around relating to others.
Then the final one is procedural learning, which we learn by repetition, by doing something. It’s how you learn to ride a bike or sign your signature.

People with dementia lose some ability with the first two, but they do not lose their abilities for emotional and procedural learning.

To Keep Your Brain Nimble As You Age, Stretch It


Speaking Multiple Languages May Help Delay Dementia Symptoms

Speaking Multiple Languages May Help Delay Dementia Symptoms
April 04, 2012

The brains of people who grow up speaking two languages are wired differently, and those differences protect them from dementia as they age.

Ellen Bialystok, a distinguished research professor of psychology at York University in Toronto, Canada

Since about 20 percent of Americans are bilingual and as many as 60 percent of people in big cities like Los Angeles grew up speaking two languages, this is no small issue.

research finds that bilingual children are better at “executive processing,” which includes being able to pay attention, plan and organize thoughts.

kids who grow up speaking two languages are better at switching between tasks than kids who spoke only one language.
Researchers gave 104 children a common executive function test on a computer that asked them to sort images of either colors or animals on a computer screen.
This “switching” task tests working memory and the ability to change from one rule to another.

The children who were bilingual in French, Chinese or Spanish were better at switching categories – in essence, multitasking.
That may well be because they learn early on to toggle between the two sets of rules for English and their other language.

bilingual adults maintain better executive functioning later in life than monolingual people.
That extra “cognitive reserve” may allow the brain to better cope with the damage caused by dementia, thereby delaying symptoms. (Being physically and mentally active has also been shown to have cognitive benefits.)
Trends in Cognitive Sciences.

But what about those of us who aren’t bilingual? Are we doomed?

“The kind of story we’re telling about bilingualism and dementia is not that bilingualism is the only inoculation against dementia, but rather, bilingualism is one of the many things we know that contributes to cognitive reserve,” Bialystok says.
“It’s why you’re supposed to do crossword puzzles and exercise and learn a musical instrument.
If you’re not bilingual but you’re active and engaged, you’re getting cognitive reserve.”

Still, bilinguals do have a natural advantage, she notes, because they can stay active and engaged without making a huge effort.

“Nobody spends all day every day doing crossword puzzles, but everybody spends all day every day talking,” Bialystok says.
“It’s a way to get massive doses of this stimulating activity without doing anything special.”

original articles:
Bilingual Effects on Cognitive and Linguistic Development: Role of Language, Cultural Background, and Education
Raluca Barac, Ellen Bialystok
Child Development, March/April 2012, 83 (2),  pages 413–422,

Bilingualism: consequences for mind and brain
Trends in Cognitive Sciences, 30 March 2012, 16 (4), 240-250,