and when we included perceptual speed in the equation, when we looked at that
variable, it accounted for almost all the relationship between age and memory.
Only a little bit was left over. So it reduced it, but reduced it a lot
more than this intrinsic value of health. So congnitive, primitive cognitive
variables like perceptual speed, or even working memory can account for a large
amount of this age, memory relationship. I call them cognitive fundamentals, like
perceptual speed. But health itself accounted for a very
small amount of that relationship. So cognitive variables can attenuate
significantly the age memory relationship but health cannot.
There are also extrinsic variables, things, things that we develop through
experience like for example, we were born in a very different time, we're very
different care for young children. Very different educational experiences of
a 60-year-old versus a 20-year-old. They just came up at a different time and
that's called, a birth cohort. The birth cohort had shared these kinds
of experiences when growing up, which are very different from the kinds of
experiences that are shared By younger people or maybe it's culture the OLI that
you read about aging and memory talked about the fact that culture the
difference in Eastern and Western people is Eastern people have a tremendous
respect for older adults and Western people sort of don't.
And maybe that those differences create stereotypes of what memory is going to be
like when you grow older. And they show that in Chinese older
adults the differences were much, much smaller than you see with western adults.
That's a culture phenomenon, or it could be simply Laboratory Task Experience.
When you think about it, college students a typical young group have a lot of
experience with taking tasks and coming into a task and taking tasks.
But older adults haven't done that since they were in college, or if they went to
college or in high school. So, maybe it's the differences in the
anxiety that's produced by having laboratory task experience.
Maybe the age difference would be small if I looked at more every day tasks, for
example. So, the educational experiences can be
something that's very different, and that produces the memory differences and other
kinds of environmental differences. So, there are lots of things that'll do
to experience [UNKNOWN] that might account for it.
Let's look at a couple of those. First birth cohort, the best way to look
see if birth cohort is a problem is do longitudal studies.
When you compare the same people as they grow older, so we have the same birth
cohort, that's not confounded with age. And we look at these longitudinal data
versus the cross sectional that we do when we compare 20 year olds to 70 year
olds. The most famous longitudinal study, or
one of the famous ones, Is the Baltimore Longitudinal Study which is actually
conducted by the National Institute on Aging in their own laboratories in
Baltimore. And when you look at their study, this is
the fo, for example, the cross-sectional data between 40 and 50 year olds and 55
and 65 year olds. You see that if I look at this is errors
on a memory task, so it's errors on the ability to recall nouns and noun pairs
that have been presented. So I might present dog, tree, and when
you see dog later you have to say the word tree, so that's a paired associated
task, and here we are looking at errors on that task.
And you can see, that as you grow older you make more errors.
If I compare cross-sectionally, 40 to 50-year-olds, and 55 to 65-year-olds, I
get these increasing errors due to age. Well, is it due to age?
Now, let's look at the same comparisons, 40-year-olds to 50 55-65 in the same
people. So here we have 4 different groups.
Now we are going to just have two groups. I mean look at the data lounge of two
lee, rather that cross-sectionally. What I find is pretty much the same
thing? So, with lounge two studies, and with
cross sectional studies, we find the same things it can't be birth cohort.
The core difference is simply not there in the longitudinal comparisons.
Recently a study was published from, by Ronnlund, Nyberg, Backman and Nilsson in
Sweden and they did the Betula Swedish study.
Longitudinal study and they found, pretty much, the same thing.
If you look at the ages between 50 and 60, you find that semantic memory,
vocabulary, increases. They actually use several different
semantic memory tests. And episodic memory, the black dots and
lines, decrease and only at age 65 and 70 do you start seeing declines in both.
But somatic memory is significantly better than episodic memory, all
throughout the task. So in, in early to late adulthood, 60, 55
to 65 Increases semantic memory, decreases episodic memory.
In late adulthood, you see decreases in both longitudinal studies show, pretty
much, the same thing you find in cross sectional settings.
Also, I mention that maybe it's the experience with laberatory tests, Do we
find age differences in everyday tasks? And the answer is, yes.
We can look at memory for faces, all these studies have been done, memory for
performing acts. When did you perform something?
Memory for maps, memory for conversations that you've had, memory for TV program
content, memory for news, from newscasts. Memory for appointments and memory for
prose, in all of these you find age differences.
So an everyday task as well as laboratory tasks we find the age differences in
episodic memory. Now the final conclusion that I want to
talk about is that age differences on memory or specially susceptible to false
memories or memory illusions that we talked about when we discussed memory.
I want to read you a quote from Mark Twain's autobiography.
He says, I have grown old and my memory is not as active as it used to be.
When I was younger I could remember anything, whether it happened or not.
But my faculties are decaying now and soon I shall be that I can not remember
any but the latter. It is sad to go to pieces like this but
we all have to do it. In other words, he's saying you'll
remember things that didn't happen as he grows old and that's exactly what we
find. Do you remember the, the false memory
study that we actually did in class, where I presented a list of words, nap,
bed, pillow, dream, pajamas and snore. I had you recall them, but you can also
do a recognition test where I give a list of words and you have to check the words
that you saw on the earlier list. And what we found was that more often
than not People will remember the words that they saw, that's called veriticle
recall, real recall, words that were presented.
But they also remember the word sleep, even though it was not presented.
We did a study comparing young and old adults with this, and we found typical
finding with [UNKNOWN] memory, the list of words that were presented earlier.
The young recalled more of the words that were presented than the old did.
But if you look at false recall, that remembering of the item which was not
presented, old people had more false recall than did young people.
So, greater amount of false recall in older adults, and a smaller amount of
true recall, veridical recall, in older adults.
So older adults are especially susceptible to false memories.
So let's go over now the conclusions that we've reached from looking at the aging
and memory literature, after my 30 years of research and the research of many
others. First, age affects only some memory
systems, episodic memory and working memory.
Second, individual differences increase with age, they don't decrease.
We become more different, not more alike. Age differences in memory can be reduced
by other non-cognitive factors, but not eliminated by them.
In fact, most non-cognitive factors have a small effect on the age memory
relationship. And finally, older adults are especially
susceptible to false memory or memory illusions.
Thank you.