Suppertime. After a morning nap you did do
your exercises, thirty minutes worth anyway. Tim came over to mow the yard;
first, it took a few minutes spending time adjusting the mower height up about
three/fourths of an inch. He also trimmed and raked where needed. You got more
ice for Carol’s machine and you bought her an unusual cane from uptown’s Yost
Pharmacy. Carol had two ladies come in today, one a nurse for blood work and
another for physical therapy. She is in good shape but they don’t want her
using a cane until next week because there are more (new) exercises to work on.
– Amorella
1821 hours. It is too late for another nap but I’m tired
anyway. I need to get a new (better) wastebasket for the kitchen the lid doesn’t
stay down on the old one. I’ve been checking online for some ideas. If I go out
to Home Depot and walk the aisle I’ll get in another ten minutes of exercise
anyway. Everyone is having a bowl of mixed fruit for supper. We had take out
from Piada Street Food Italian for lunch. I don’t know what we’ll do tomorrow. Mary
Lou will be here for lunch. Wednesday Kim will be back – time for another
Outback Wednesday lunch special in take out form. I’ll bet I’ll have to go to
the grocery tonight.
Later, orndorff. – Amorella
1944 hours. I was reviewing BBC and found this interesting
article on brain memory.
** **
Science & Environment
Peeking into the brain's filing system
By Jonathan Webb
Science reporter, BBC News
5
July 2015
Storing information so that you can easily find it again is a
challenge. From purposefully messy desks to indexed filing cabinets, we all
have our preferred systems. How does it happen inside our brains?
Somewhere within the dense, damp and intricate 1.5kg of tissue
that we carry in our skulls, all of our experiences are processed, stored, and
- sometimes more readily than others - retrieved again when we need them.
It's what neuroscientists call "episodic memory" and
for years, they have loosely agreed on a model for how it works. Gathering
detailed data to flesh out that model is difficult.
But the picture is beginning to get clearer and more complete.
A key component is the small, looping structure called the
hippocampus, buried quite deep beneath the brain's wrinkled outer layer. It is
only a few centimetres in length but is very well connected to other parts of
the brain.
People with damage to their hippocampus have profound memory
problems and this has made it a major focus of memory research since the 1950s.
Quick learning
It was in the hippocampus, and some of its neighbouring brain
regions, that scientists from the University of Leicester got a glimpse of new memories being
formed, in a study published
this week.
They used a
rare opportunity to record the fizz and crackle of single human brain cells at
work, in epilepsy patients undergoing brain surgery.
Individual neurons that went crazy for particular celebrities,
like Clint Eastwood, could be "trained" to respond to, for example,
the Statue of Liberty as well - as soon as the patients were given a picture of
Clint in front of the statue.
It seemed that single brain cells, in the hippocampus, had been
caught in the act of forming a new association. And they do it very fast.
But that outer wrapping of the brain - the cortex - is also
important. It is much bigger than the hippocampus and does myriad jobs, from
sensing the world to moving our limbs.
When we have a particular experience, like a trip to the beach,
different patches of the cortex are called up to help us process different
elements: recognising a friend, hearing the seagulls, feeling the breeze.
So traces of that experience are rather scattered across the
cortex. To remember it, the brain needs some sort of index to find them all
again.
And that, neuroscientists generally agree, is where the
hippocampus comes in.
"Think of
the [cortex] as a huge library and the hippocampus as its librarian,"
wrote the prominent Hungarian neuroscientist Gyorgy Buszaki in his 2006 book
Rhythms of the Brain.
The elements of our day at the beach might litter the cortex
like specific books along miles of shelving; the hippocampus is able to link
them together and - if all goes well - pull them off the shelf when we want to
reminisce.
Completing patterns
Another brand new study, out this week in the journal
Nature Communications, looks inside the brain using fMRI imaging
to see this filing system in action.
By getting people to learn and remember imaginary scenarios
while inside a brain scanner, Dr Aidan Horner and his colleagues at University
College London collected the first firm evidence for "pattern
completion" in the human hippocampus.
Pattern completion is the mechanism behind a phenomenon we all
recognise, when one particular aspect of a memory - the smell of salt in the
air, perhaps - brings all the other aspects flooding back.
"If you have an event that involves the Eiffel tower, your
friend and, say, a pink balloon… I can show you a picture of the Eiffel tower,
and you remember not only your friend, but also the pink balloon," Dr
Horner told the BBC.
While his volunteers had just this sort of experience inside the
scanner, Dr Horner saw interplay between different parts of the cortex,
associated with different parts of a memory, and the hippocampus.
The brain
activity flowed in a way that showed "pattern completion" was indeed
underway - and the cortex and the hippocampus were working just like the
library and the librarian in Prof Buzsaki's analogy.
"If I cue you with the location, and I get you to
explicitly retrieve the person, what we also see is activation in the region
that's associated with the object for that event," Dr Horner explained.
"So even though it's task-irrelevant, you don't have to retrieve it, it
seems that we still bring that object to mind.
"And the extent to which we see that activation in the
'object' region correlates with the hippocampal response. So that suggests that
it's the hippocampus that's doing the pattern completion, retrieving all these
elements.
"It's able to act as an index, I suppose, by linking these
things together - and doing it very, very quickly, that's the key thing."
If the cortex were left to make its own connections between the
fragments of a memory, he added, it would be far too slow.
"That's
clearly not a system we want, if we're going to remember a specific event that
happens once in a lifetime."
Dr Horner said the findings also dovetail nicely with the
single-neuron, celebrity-spotting results from the Leicester study.
"We can look across the cortex and the hippocampus, and we
can relate it to recollection. But what they can do is say look, these cells
[in the hippocampus] have learned really quickly.
"So that's the sort of underlying neural basis of what
we're looking at, at a slightly broader scale."
Science, it seems, is finally managing to unpick the way our
brains record our lives. It is a remarkable, beautiful, fallible system.
Building some sort of memory storage like this is regarded as
one of the next key challenges for researchers
trying to build intelligent machines.
Our own memories, for all their flaws, are a hard act to follow.
Selected and edited from - http://www.bbcDOTcom/news/science-environment-33380677
** **
1952
hours. I wonder – if it were not for memory where would any of us be?
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