I have to say, I'm totally delighted and thrilled,
and as I was saying out there, I'm probably still in a state of shock, so if I sound like I'm in a state of shock,
it's because I am in a state of shock - it's a terrific accolade.
It is the
highest accolade you can get
and I think it's a terrific sign of
the way the world thinks about the work – I think about the work we've been doing and
about British neuroscience,
and I have to thank UCL – UCL has been a terrific place to be,
and has been very good to me and allowed me to do the science
that we're all here celebrating.
We knew from work by Brendan Milner that
damage to this part of the brain that I've studied my for my whole career – the hippocampus and surrounding
areas in humans – led to a profound loss of memory,
a profound amnesia, so had that basic clue.
We had the idea that the hippocampus and perhaps areas that
connected with it, were actually involved in memory. So I thought, okay
we now have techniques, which I was partly involved in
developing, for actually looking at and listening to the activity of single
cells
in an animal such as a rat, as they were doing simple
memory tasks, and that's what I decided to do.
When I went into this part of the brain, I hadn't the slightest idea and no one else had
the slightest idea that it was going to end up
being a spatial memory system,
and that was the great surprise – the great surprise was not that it was a
memory system, but that it
in animals such as rats and mice, it's dedicated to
memories for spatial
events. And when I saw the cells that
were
responding when the animal went to one part of the room not the other part of the room,
and recorded from several of these and found that one would be interested in this
part of the room,
and another in that part of the room, then I a realised that
if you put them altogether, you would have something like a map, and that would be a really
super thing to have, to find your way around, to remember what you had
done in particular places and particular times.
So I remember that that was a point at which I thought, 'hmm,
this could be an important finding'.
So when we first discovered the place cells and realised that different cells
respond to different places, I thought wouldn't it be neat
if they knew about each other and there was some way in which
there was a neural system for communicating from one to the other
and for providing information about the spatial relationships between the cells.
So if I know that I will be here and I know that I want to go over here,
then what I really would like to know is some information about the distance and
direction
which connects these two places. So we supposed
even early on that there would be other spatial signals in this system –
there would be signals which were representing directions in an environment –
how do you go in this direction –
and I don't mean just north and south in terms of geomagnetism, I mean
ways in which you could actually go for example
to that corner of the room.
And you also expect to have some sort of metric –
is there a metric system in the brain, is there some way in which
an animal, the rest of the brain knows that
it is moving at a certain speed in a certain direction and
going therefore, say
for a rat or mouse, say 30 centimetres
per second. And so we suggested that that might be there, and we now know
we have been idle for the last the last 40 years, but
our lab and many other labs around the world have discovered
these other spatial signals, so we know there are cells which respond
if the animal looks in a particular direction and if you take
all those cells and put them together they form a kind of compass,
which says you're now looking, as it were,
in the north part of the room. And then of course there are the cells that were found
by the moses, which
layout this very nice grid pattern across
any environment, so if you or an animal walk around this environment, they don't just respond
in one place, they respond in a whole bunch of places
and these individual places add up to make a very nice
pattern – a hexagonal pattern – which lays out a grid structure across the whole
of the environment. So you can imagine, as you walk along
from this place to another, the first
position it goes 'brrp', and then it goes a little bit silent, and then it goes
'brrp' – those 'brrps' occur at regular intervals,
so that other parts of the brain could say 'ah, you've gone three brrps', 'you've
gone three right steps in a particular direction'.
We know there are other cells, in addition there are cells that measure
how fast the animal is moving,
cells which tell the animal about large landmarks, so we think we have
all of the ingredients, all of the components for
creating this mapping system, and if you put them together,
they enable the animal to do something very unique – they can move around the
environment flexibly.
So you can always go from one place to another by following your route;
you can say, 'I'll go down to the corner, turn right, go four steps,
turn left' and so on. What this system will enable us and animals to do is to
actually
say, 'I want to go to Trafalgar Square –
how do I do it? Well, let me go out the front door
of the building here, go along Euston... oh, the police have blocked off Euston Road.
I know another way', and it will enable you to then go via a totally different route,
one that you hadn't anticipated,
and we know this exists because we've seen it actually
operating in cab drivers, as Eleanor McGuire
at UCL has shown –
when a cab driver is trying to plan a route,
and to find a route to say Soho or down to Trafalgar Square, this part of the brain lights up
and stays active as long as they're planning the route. When they get to
follow a very simple
route, like go along Euston Road, then you don't need this part of the brain.
Simple pathways, routes where you know and have learned them over many years – you don't need this.
You need this part of the brain
to be flexible, to actually do something which is novel,
to do something which is unexpected, so it could be one of the areas in the brain
which actually provides us with a...
...sorry.
And you can build on that, in
humans it's used not only for plotting routes and things like that, it's used for remembering
what you did in particular places, particular times, what you did yesterday
for lunch, and it's also used to plan the future –
'what am I going to do tomorrow?',
and even to make up stories image what you might do in
your imaginary world. So it's the basis
for a very, very powerful cognitive system which enables
many of the important cognitive aspects of our minds to work.
The basic message that I as a scientist and
now as someone who's leading an institute would
try to convey is that I think science
is part of the intellectual life of a country,
it's an important part of its own sake –
just the going out there and trying to understand the world is very, very important
I think
in addition to that it's very important for the economy; I think we need to
have a science-based economy and
the sooner and the quicker we move to that
situation, where we have basic science which then gets translated
from the laboratory into either medical cures or
into industrial products,
is very, very important. I think we're making progress in Britain on developing that
culture,
but I think we could do a lot more, and of course we can always use more money
in science, and I guess that's the sort of message I would like to
propose and that basic curiousity-driven science
is very, very important – it's not only very important, it's crucial –
for all of science, and we should nurture it and we should
try to
encourage it as much as possible, because that it in fact
in the long run where our cures and our
industrial power will come from.