Learning and memory
are bits of writing from many sources such as personal correspondence,
posts to on-line discussion groups, notes, and occasionally even some
All of this is informal in nature, but contains some interesting and/or
muscles from a skull?
[Posted to the
group on MySpace.com]
like this many times: Your brain is a muscle. Use it or lose it.
Yes, but it is
to note that the types of mental exercises that are effective are very
different than those that develop muscles.
you want to build your muscles, you to repetitive movements with heavy
objects. By contrast, the mental exercises that seem to be the most
are ones in which your brain is constantly challenged by *novel*
not rote tasks (in other words, the point "dp" is making above). You
to constantly be engaged and kept on your toes.
of vocabulary words or Latin that you will never use is actually
That knowledge becomes compartmentalized instead of generalized. The
a piece of knowledge is applied, the broader (and more plentiful) the
connections are in the brain... thus, neurodegenerative diseases have
break more connections to have as dramatic an effect on cognition.
You have to
what is meant by "use" in "use it or lose it" before you go on a mental
workout that might just lead to stagnation.
[Posted to the
group on MySpace.com]
A few more
on this topic...
Like I said
the "use it or lose it" aphorism is ambiguous and misleading. Use what?
And use it how?
is much better to describe what to avoid. You wouldn't say someone
a book was mentally inactive, but you might view someone doing the same
repetitive task over and over (admittedly, this could include reading
same formulaic romance novels and Mack Bolan adventures).
address this either way, but no one has mentioned the studies of
vs. impoverished environments regarding this issue. While rats would
be more mentally active if they had some stimulus vs. none at all, it
that the effect of the enrichment wasn't just to promote activity but
activity. Rats moved from one task to another, and the result was that
their brains were rich in synaptic branching. These dense connections
to be what prevented the nuns in the famous (and on-going) study from
By having a
generalized (i.e., cross-connected) brain, individuals with AD are less
likely to present the symptoms until the disease has progressed
The simple reason for this is thought to be that they have multiple
to finding the same information. In other words, they can do the same
in a number of different ways.
this would be to become very good at only a narrow set of behaviors.
brains would have strong connections only in the relatively few
associated with the heavily-practiced tasks. If any of those
is severed, the knowledge and/or abilities conferred are lost.
A parallel to
in the educational community is a reaction to "teaching the test."
testing has proliferated (e.g., SATs, ACTs, state-mandated tests, etc.)
such that the style has been to teach to the test. In other words, the
emphasis has shifted from the content to the format of the test and how
to figure it out.
best approach is to cover the material in such a way that students can
generalize their knowledge. If they encounter something on a
exam that throws them, they would do better to use genuine intelligence
and a broad array of knowledge to figure it out than resorting to
bag of tricks only applicable in a finite set of circumstances.
an archeological expedition sometimes. I run across things all the time
in movies, etc., where I go, "Oh, so that's where that came from."
I know all the words to several verses of "No one will suspect you're
(I don't know if that's the actual name) from "The King & I." I
out only a few months ago that was where it was from. There are still a
couple others that I'm trying to place.
[Posted to the
group on MySpace.com]
I don't know
the line is between addiction and associative learning, but there is
some overlap in a number of areas (for example, relapses are often
by environmental cues drawn from associations made while using the
As far as
association pairings, there's an example that stands out as
unique in associative learning, and that's food aversion learning.
you typically have to have numerous bad experiences with something
you consistently avoid it, you only have to get sick after eating
*once* before you have trouble with even the smell of it for many years
This is a
conveyed learning mechanism that keeps you from eating anything that
body had a bad reaction to before. Interestingly, it doesn't even
what actually made you sick on that fateful pairing. You may very well
have gotten sick from something else entirely (e.g., a stomach flu) and
happened to have thrown up your most recent meal. Guess what? That's
last time you may ever eat that food again.
And it cuts
ways. This also happens to be why those colorful-but-poisonous insects
are so effective in their highly visible carapaces. A bird (or other
only has to eat one member of the species once in its lifetime to
that a nasty association is created in that bird's mind. Thereafter,
rest of the species is protected.
[Posted to the
group on MySpace.com]
visual cortex...to find that they can still process complex visual
There are a
of parallels with memory in this and other things you mentioned. For
in the '20s and '30s, Lashley performed a similar set of experiments
on rats) to find the "engram" that encoded a particular memory. Guess
He failed. Actually, what he found was that the more of the cortex you
remove, the worse the rats got at the task (which in this case was
a maze they had previously learned), but they still seemed to remember
the entire process. Of course, this wasn't a terribly sophisticated
but it did demonstrate a similar phenomenon.
hemispherectomies are performed on humans (almost always on children
several reasons*) which leaves them with far more than the expected 50%
of function by almost any measure. One would think that they should
half their language ability, memories, etc., but apparently this is not
the case even though some deficits present themselves.
above include the fact that this surgery is almost (always?) performed
on patients with intractable and debilitating seizures. The cause of
is often due to a condition known as Rasmussen's encephalitis, which
presents itself in children under the age of 10. Further, children have
a substantially greater chance of cognitive improvement following the
thanks to their greater plasticity.
There's a term
on cerebral hemispherectomies on the science page of my site if you're
interested in reading more about the topic.
>I saw a
some sort of functional imaging of the brain looking at simple shapes
the brain emitted signals/patterns that were in the very shape of the
very likely the case. You have to realize that there are literally maps
of things on our brain. For example, we have a map in our somatotopic
that is arranged just like our bodies (i.e., hands next to arms, arms
to torso, etc.). You also have a similar map on your motor cortex,
it indicates which parts should move, whereas the other map indicates
we feel physical stimuli on our skin. The level of detail in these
can, in the case of rats, for example, go down to the level of their
whiskers. This particular example is a very popular target for a number
of lines of research, in fact.
cortex, rather than perceiving things externally, this area picks up
external world in front of our eyes, so it has a different map
There have been studies focusing on this area in which, for example,
cells across the cortex were labeled according to which cells were
while an animal looked at a fixed image (You can also record the
of the cells with electrodes and get similar data). If the image
to be something like a black and white letter "E," you would find that
the image (being relatively simple) would appear in a similar form on
tried to track down some images to show you, but most of these are in
journals themselves, so I couldn't find any good illustrations of any
the above phenomena. Sorry. If I happen across something, I will try to
remember to post a link. Or if anyone knows of a good picture, please
up my slack.
known at the time...that video clip was probably a hoax
I would have
see the video in question to assess it, but it sounds legitimate. Of
they also might have exaggerated things for effect, so it might have
across as "too good to be true."
see a chair, your neurons are literally firing in the visual cortex a
of the chair.
The reason why
used the "E" example above was because at higher levels of processing,
you would have a lot more things going on. Specifically, you have two
parallel pathways that each process different aspects of an image
its shape, movement, color, etc.). We're still working out the details,
although a lot is known so far. So, yes, at the *primary* level (i.e.,
in the primary visual cortex), you would "see" an image literally on
brain, but things get pretty wild after that.
"one-to-one" question, I think what you're really interested in is not
just vision, but consciousness. There is a much-debated concept usually
referred to as the "Grandmother Cell" that looks at that. The idea is
all processing eventually leads back to an internal representation of a
single idea. So, when you see your grandmother, all the neurons process
information until they reach this single point that represents your
There are ongoing debates about the merits and downfalls of such a
and the matter is apparently far from settled. There's a link to an
article on it below. Note that is was published in 1996, so there are a
few things I know would have been included were it written today, but
the same, I have a feeling it's right up your alley. More than just
about the concept of "grandmother cells," however, I think it's a good
illustration of how difficult it is to get at some of these questions.
on (or by?) grandmother cells
drivers and neuroscience
There was a
of the London cab drivers years ago that found that they had one
of their brains (can't remember which) that was developed to three
the size/density of the average person. The reason they chose London
because it grew up organically without much in the way of civic
Consequently, it's a complete mess, so drivers have to develop loads of
mental maps in order to find the most reasonable routes.
I wanted to
anyone learning about LTP that not everyone is convinced that this is
core mechanism underlying the formation memories. However, you could
the impression that the debate has been settled if you look around the
literature casually. This is largely due to the prominence of Eric
in the public and academic realms. He is so central to the study of the
phenomenon, but he is also highly visible (e.g., Nobel Prize, his own
text, and at least three appearances on Charlie Rose that I'm aware
That presents something of a biased perspective to outsiders when the
is not firmly settled within the field.
in Kandel's camp for a number of reasons that I won't go into here, but
if you are interested in some of the arguments against LTP as the basis
of learning and memory, check out Randy Gallistel's chapter in the book
"Conversations in the Cognitive Neurosciences." It put a few doubts in
my mind. (Note, however, the interview was conducted around 1997, so
his arguments have been addressed experimentally in the interim.)
email with Dani]
suddenly everything happened. So suddenly, I don't even REMEMBER!!
was that, by going unconscious immediately upon impact, whatever was in
your short-term memory was never written to long-term memory. This also
happens when people come out of a faint; they don't remember going into
one, so they try to walk or continue a conversation just as if they
in the middle of something mere moments before.
There was a
case in which the perpetrator claimed to have been knocked unconscious
by an unseen assailant, but was caught in a lie when he (or she?)
details right up to the impact of the bludgeoning. The neurologist
in the matter flat out told the detective, "That's imposable." The
A few yeas
my girlfriend experienced the post-trauma metabolic depression (as
by memory impairment) that is common with concussions. We were in a
car accident and she was knocked unconscious. Fortunately, I'm
and nothing happened to me. I'm not sure if she technically had a
or not (since I don't know the medical criteria/diagnostic definition),
but as is so often the case in events such as this, she had no memory
events leading up to the accident.
on-going memory problems for roughly a month afterward as well. The
severe were, of course, in the days immediately following the wreck.
example, a couple days after the accident, I took her grocery shopping.
Since she was still really sore, I would ask her what she wanted, tell
her to wait with the cart, then go get things and bring them back to
The first time I did that, I came back with a couple gallons of milk
she wasn't where I told her to wait. "Where did you go?" I asked. She
at me like, "I was shopping(?)." I asked her why she moved from where I
left her and she had no memory of the conversation.
symptoms gradually let up, so now she has to make other excuses to
things I've said.
Dani refers to
accident as "rolling back to zero" or something to that effect. It
almost a year after we started going out. Even a year afterward, she
us as missing that year. She always thinks we've only been together for
a year less than we have been in reality.
I don't know
anyone has a clue about the information storage properties of the
Instead, the research into learning and memory are primarily focusing
the creation and maintenance of associations between pieces of
flawed) computer/brain analogy, the short-term memory issue Tim
above might be thought of as an issue of consciousness being our RAM,
in the things that we're aware of that are in our short-term memory. As
much as I love analogies though, we all have to be careful about
by analogy. Just because "A is to B" doesn't mean that just because "C"
is analogous to "A" that "C is to D."
is possible to scan pages and pages of material in a matter of minutes?
I would say
most cases) no. The reason is that a lot of the things our brain does
grounded in existing wiring. Let's take perception to begin with. There
are a lot of optical illusions where you don't know what you're looking
at unless someone points it out or makes you look at things a different
way. The information was always there, but you had to have an "in" to
it. If you happen to be looking at a page full of words, you really
to almost know what the page is trying to say before you attempt to
it. Of course, you're probably trying to read it because it's something
you haven't read before, so you haven't seen it yet for this to work.
Catch 22. As a result, if you gloss over something, you aren't going to
have the mental traction to make any headway through it. You have to
it bit by bit the way tires grip the road in order to move forward.
This is a
on the above, but another example of prior wiring being important is
you have to understand the material to some extent already. I'm sure
seen "The Sixth Sense" already, right? Well, the first time you saw the
movie through, it was a completely different film than the second time.
Without that understanding of the true situation, you don't fully pick
up on all the meaning. If you read too quickly, you don't catch all the
information that establishes the context, so what you're reading is not
necessarily what the piece was about. You may be missing key points.
important constraint is that learning actually takes time. Since
(even in the short term) takes place by physically connecting neurons,
you cannot shorten the process indefinitely. There is some lower limit
ultimately, and approaching that minimized the efficacy of the
going below that means there is no measurable learning at all. I'm
in particular about a process called long-term potentiation or LTP. You
might look that up in Wikipedia if you want some more background.
techniques I'm aware of tend to operate not by reading faster but
through selective omission. For example, you only read nouns and verbs
or maybe you only read the first and last sentence of each paragraph.
not sure if the approach you're looking at works that way or not.
enlighten me when you get a chance.
up my reading time...I feel like I read so slow..I have excellent
of the material.
are related for precisely the reasons I mentioned above. There's more
it than that, of course, but that's part of it. Reading slowly is like
chewing your food instead of swallowing it whole. If you just need a
awareness of something, then skimming it would be fine. If you want to
be aware of every detail and/or want any sort of emotional impact from
it, then you are going to want to read it at the pace that is most
not sounding out the words or anything...the reason I read slow is
when I read I have a voice that comes on in my head...(strangely it is
not my voice..or even my perception of my voice..it had a British
is kind of like the narrator of the National Geographic...I can't turn
I get that more when I write in certain styles than when I read.
This is more a
than a comment on the above, but one approach you might try is to use a
text-to-speech program. You can paste text into it from wherever
web pages, etc.), and it will read to you in a still far-from-perfect
at a human voice. However, the more you use it, the more effective it
because you gradually get used to it. Sure, it doesn't always pronounce
things correctly, but your brain fills in those gaps just like when you
pick up on the nuances of any language (e.g., Spanish, ASL, computer
visual shorthand like that found in movies and commercials, etc.). At
I have a pair of cordless headphones I can connect to my computer, so I
can load a couple chapters from a book and wander around doing
or even in my yard cutting the grass, washing the car, and so on.
in trying out one of these programs, one of the better ones (for free
is the basic version of Natural Voice Reader.
I think we all
a lot more should be there than actually is. I mean, I think back and
to remember, say, who I ate lunch with when I was in college even, and
a lot of the time I can't come up with a lot of people. However, later
on I'll remember something that happened and I'll realize someone else
who was there at the table. You have to come at some memories sideways,
which is why therapy helps with this (But watch out for invented ones
ritual molestations by devil worshipers). Here's an exercise I did
I made a list of all the books I had ever read. I thought I had done
well on the first pass, but I ended up with maybe another 25% or more
the next few days that I had completely forgotten about, then another
over the next few weeks. Since then I've come up with a few more titles
(about one every few months). They were part of my past, but it will
me getting on the subject of one before it dawns on me that I ever read
with you this way?
about this and I can't figure it out.
An example of
I came up with was the fact that I can remember my schedule my freshman
year of college, but I can't even remember some of the classes I took
a couple years ago. The level of detail that stuck with me back then
really, really intense whereas now I hardly recall anything
and chemicals lead to memories?
still far from worked out completely, in theory, it apparently isn't
that difficult. I mean, there are a number of different information
Admittedly, they're usually quite a bit different than the brain, but
even surpass our abilities in terms of speed and accuracy of recall,
to pick one example.
This is a more
question. Check back in a hundred years. Or maybe we'll all be stored
and be on-line by then. In which case, let me say hello to my digital
who will be reading this after my physical death. "Hello,
>If we ever
out how the brain works fully, if it can ever be done, think of the
things that can be done. Like you can be on the internet or something
get massages, have sex, feel things in cyberspace if they knew how to
brain-computer interfacing and/or transhumanism. Those are both terms
essentially the same thing. You can find a lot of speculative pieces
essays, etc.) on transhumanism, but there is also time devoted to the
of brain-computer interfacing at the SfN conference. I haven't looked
the schedule yet this year, but there is usually a symposium with
after speaker presenting research and relevant engineering and/or
into the this area for at least a day, but I think it ran for two days
the last time I was there. If you aren't there to see anything else,
can sit in the auditorium and gorge on the information until your brain
but the blank slate model assumes nothing is wired together. Since that
is not the case, it means the brain comes with wiring that has built-in
(or in-built) meaning.