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Michael Breakspear “A theory of cognitive function based on corticohippocampal waves”

March 09, 2023
ID
9627

Transcript

  • 00:07And I'd like to make time for organizing
  • 00:10and and the smart ticker and everybody else
  • 00:14who's organized this functional meeting.
  • 00:16And yeah look I don't normally given you
  • 00:19talk because there's just so much work
  • 00:21but I thought the Todd and you guys,
  • 00:24I'm going to write it for from scratch.
  • 00:26It's a long plane ride and there's a
  • 00:29long lonely jet lag nights being awake.
  • 00:32Alright, this is you.
  • 00:33I just finished this book at 3:00
  • 00:35o'clock this morning. Sorry,
  • 00:36it's it's probably going to be terrible.
  • 00:41Turning out good. So
  • 00:44we're going to talk about an experiment.
  • 00:48Since we do do those sometimes still,
  • 00:52then I'm going to talk about some
  • 00:54pretty complicated analysis.
  • 00:55That experiment which could
  • 00:57easily occupy the 30 minutes.
  • 00:59I have to run through all the details
  • 01:02because it's really just using a couple
  • 01:05of snapshots from the results to.
  • 01:10Motivate my theory of the brain how it works,
  • 01:14which is hopefully not that complicated.
  • 01:16There's an Australian so
  • 01:18can't be too complicated.
  • 01:20So I'm gonna start with this experiment.
  • 01:22This is work I did quite a long time ago.
  • 01:25In fact, I worked with semen on this paper.
  • 01:28We have a collaboration,
  • 01:29but this was with Christine
  • 01:31Gower and New Don Ren.
  • 01:33So our interaction with the world
  • 01:35continually informed by memories,
  • 01:37right, which you retrieve
  • 01:39naturally without mental effort.
  • 01:40Sorry, you're going to see me.
  • 01:42If I walk out the door and I
  • 01:44come back in few minutes later,
  • 01:45you go on this final breaks,
  • 01:47alright, he's giving a talk and
  • 01:49we don't really think about this,
  • 01:50it just happens.
  • 01:51So there's some sort of breaks in
  • 01:53the stream of consciousness and then
  • 01:55there's some way of gluing it all
  • 01:57back together a few minutes later.
  • 01:59So imagine you're watching the news.
  • 02:02You go with this advertisement
  • 02:04and you go to the fridge,
  • 02:05get across the border or you get put
  • 02:08in a scanner. And then after the ads.
  • 02:13Comes on the rest of what you were watching.
  • 02:14So in this case, we wouldn't really
  • 02:16have an ad, but there's a news
  • 02:18reader in the in in The Newsroom,
  • 02:20and then there's a break.
  • 02:22And then we put people in the scanner.
  • 02:24And then we watched two types of movies,
  • 02:27either those that were the news item
  • 02:30that really newsreader was reading
  • 02:33out or something completely random.
  • 02:35Another news clip, I should say.
  • 02:37So his new thread is saying, you know,
  • 02:40terrible storms in Brisbane today.
  • 02:42Uh, that kind of ****** the
  • 02:44reporter on the ground.
  • 02:45And this is the continuing condition.
  • 02:48Yeah. Thank you.
  • 02:49I don't know who this guy is,
  • 02:51but he's American comedian.
  • 02:53Thanks, Ted. Yeah, very bad.
  • 02:55Brian here.
  • 02:56Or it goes to this picture of a Pussycat.
  • 02:59Yeah. Firemen were called to,
  • 03:01to to get this cat out of the tree.
  • 03:04This is the sort of it could be.
  • 03:07And and it's all counterbalanced.
  • 03:08So sometimes there's clips
  • 03:10of the continuing 1.
  • 03:12These are results in this paper was
  • 03:15from small number of healthy adults,
  • 03:18but then we put this into a big study
  • 03:22with 186 healthy adults and I'll also
  • 03:24show some people with mild cognitive
  • 03:27impairment and Alzheimer's disease.
  • 03:29So these effects are really strong.
  • 03:31These are statistical maps,
  • 03:33right?
  • 03:33So I'm gonna get with Tim and
  • 03:36say it's not necessarily a lot of
  • 03:38great activity that's changing,
  • 03:40but if you put 186 people into the scanner,
  • 03:43you're going to get even with
  • 03:45weak changes in brain activity,
  • 03:47you're going to get strong
  • 03:49statistical affairs.
  • 03:50So this is like family wise error
  • 03:52corrected at the Vauxhall tenant,
  • 03:54minus four or five or something,
  • 03:57huge effects of watching the clip.
  • 03:59Compared to the rest breaks in these
  • 04:03visual product rattle executive
  • 04:05areas and then if you do the
  • 04:08reverse GLM we see the default mode
  • 04:10and that's not that interesting.
  • 04:12But what's quite interesting to me
  • 04:14is that if you do the the reverse.
  • 04:17So if you just take the film clips
  • 04:19and I'm just showing you this to
  • 04:21convince you that something quite
  • 04:23interesting is happening here
  • 04:24if you look at the naive Cliff,
  • 04:26the Pussycat and the tree compared
  • 04:28to the storm.
  • 04:29Are you do you see this very
  • 04:31localized effect?
  • 04:32This is the only effect in the brain.
  • 04:35Other statistical threshold.
  • 04:36This is like the something like
  • 04:39the parahippocampal place area.
  • 04:42I call this looking for the sock network,
  • 04:44you know, you know,
  • 04:46you're looking at the film tip going.
  • 04:48What's going on here?
  • 04:49I mean, a lot of people have this
  • 04:51response when they're hearing me talk,
  • 04:52actually.
  • 04:55I'm always looking for my sock right?
  • 04:59And then I find it,
  • 05:00and off to work I go 5 minutes later.
  • 05:05Response so.
  • 05:08Yep, sometimes with one shoe.
  • 05:12And this is the reverse contrast
  • 05:14and this really strong effect.
  • 05:16The clips are the same.
  • 05:19People are just flying in the scanner,
  • 05:21but when there are these.
  • 05:23Familiar semantic clues.
  • 05:25It really switches this looking for
  • 05:28the sock network into this big.
  • 05:32I guess you could call it the engram network.
  • 05:34It's like, oh, OK, this makes sense.
  • 05:37I've got an autobiographical
  • 05:39connection with this film clip.
  • 05:42I'm going to. I'm going to understand
  • 05:44the haircut of what's going on here.
  • 05:47And if you do a, the hippocampus is in here.
  • 05:51This is a hippocampus mask,
  • 05:53just to show that there's
  • 05:55effects across the hippocampus,
  • 05:56particularly in the head of hippocampus.
  • 05:59I said this is all interesting,
  • 06:00but not that interesting.
  • 06:02This is kind of what I showed.
  • 06:05If we're looking at the cortex,
  • 06:07these are boxes fly.
  • 06:08We just gotta model up with the GLM with
  • 06:11these two different direct task effects.
  • 06:14But what we did instead at begin with
  • 06:17is we put this into a API equation.
  • 06:20So we said, well,
  • 06:22they're boring, we'll get them,
  • 06:24we won't pay much attention to them.
  • 06:27We're going to have a look at the
  • 06:29activity in the cortex that we can
  • 06:31account for by activity in the hippocampus.
  • 06:34This is the baseline.
  • 06:37Functional connectivity between keep
  • 06:39careful variance and cortical variance,
  • 06:42and these are these two interesting terms.
  • 06:45So how much of what's going on in the
  • 06:48hippocampus during these two tasks
  • 06:50accounts for what's going on in the cortex?
  • 06:53This is Parker physical interaction
  • 06:55or whatever you want to call it.
  • 06:56So does everybody sort of get that?
  • 06:59We take away the task picks, take away,
  • 07:01functional connectivity and we're
  • 07:03looking at these tasks dependent modulations.
  • 07:08So these are quite huge,
  • 07:10but not that huge in some instances.
  • 07:12So this is the baseline coefficient
  • 07:15in the hippocampus.
  • 07:16I've showed the cortical,
  • 07:18these are the eggs.
  • 07:20And so that's the taste of fistic.
  • 07:22And then make a threshold that we get a very,
  • 07:24very, very, very strong pay value.
  • 07:26We can look in the cortex.
  • 07:28So few things with time here.
  • 07:31So first of all,
  • 07:32yes, Tim,
  • 07:33baseline much stronger effect
  • 07:35is much weaker task modulations.
  • 07:38Let's see the top base baseline effects.
  • 07:42But what's interesting here is
  • 07:44every hippocampus has a functional
  • 07:47connection with some part of the cortex,
  • 07:50and most parts the cortex have
  • 07:53various that can be explained by
  • 07:55the variance in the hippocampus
  • 07:57particular to that task effect.
  • 07:59So this is a better way of looking at
  • 08:01brain really this is a whole grain.
  • 08:03Everything's kind of running away
  • 08:05through like your harness talk,
  • 08:06there's big spatial modes.
  • 08:07If we get enough data,
  • 08:09we can sort of start to say that,
  • 08:11OK,
  • 08:12but then we wanted to say what's
  • 08:13the texture of this effect?
  • 08:15So we all know this work by Daniel
  • 08:18on gradients.
  • 08:19This is a purely sort of cortical
  • 08:22decomposition using a nonlinear
  • 08:24dimension reduction technique based on
  • 08:28functional connectivity in the cortex.
  • 08:30More recently, people have
  • 08:31looked at the hippocampus.
  • 08:33You find these same
  • 08:35gradients and hippocampus,
  • 08:36they differ a little bit.
  • 08:38Thanks. And review it too.
  • 08:39I learned about this and all the same.
  • 08:43Nonetheless.
  • 08:46There are functional
  • 08:48gradients in the hippocampus,
  • 08:50more or less posterior to add heria.
  • 08:54Right. So I thought, well let's do this.
  • 08:59The only who is very bright post Doc
  • 09:02Martin team went out of Melbourne,
  • 09:05worked with yeah and Andrew
  • 09:072 colleagues of mine.
  • 09:09This is a complicated technique that says
  • 09:11what's the functional connectivity now?
  • 09:13Not within the cortex,
  • 09:16between the subcortex.
  • 09:18Max, I'm part of the world as the cortex,
  • 09:21so we're doing functional connectivity,
  • 09:23kind of what I showed before
  • 09:25between every hippocampal Vauxhall,
  • 09:26or in this case every subcortical Vauxhall,
  • 09:29every cortical voxel, each.
  • 09:30It's like a you get a Gray,
  • 09:33a vector for every hippocampal Vauxhall,
  • 09:37then the Navy hearing hammer Vauxhall,
  • 09:40we'll have another vector functional
  • 09:42connectivity and you just get a similarity.
  • 09:45Matrix all subcortical boxes and we get
  • 09:50a similarity between adjacent and other
  • 09:52hip camp or other subcortical boxes.
  • 09:55You do the graphic passing.
  • 09:56You just heard about that this
  • 09:58morning and you get these lovely
  • 10:01looking gradients for this gradient
  • 10:03is how quickly is the voxel,
  • 10:05the whole brain functional
  • 10:07connectivity changing so quite slowly,
  • 10:10quite rapidly.
  • 10:10That's all we really need to
  • 10:12know about these.
  • 10:13These are gradients here and Andrew.
  • 10:15Use this part of these gradients
  • 10:18come up with these beautiful multi
  • 10:22style subcortical functional outlets.
  • 10:25So when we were chatting about this,
  • 10:27we decided, OK,
  • 10:29we can do this with the PPI, right?
  • 10:32We can see.
  • 10:36For these baseline and task PPI coefficients,
  • 10:40we'll just do the same thing.
  • 10:41So in other words, for every and we
  • 10:43just got to look at the hippocampus,
  • 10:45every hippocampal Vauxhall better look at
  • 10:48the correlation with all cortical voxels.
  • 10:52And we look at the next voxel
  • 10:54and we'll get 2 vectors and we
  • 10:55look at the similarity for that.
  • 10:57It looks very complicated.
  • 11:00Yeah, and he went back to France.
  • 11:03She let him fill the pot.
  • 11:04And Kodak could tell you it
  • 11:07is actually quite complicated.
  • 11:08They're going out on revisions,
  • 11:11but at the end of the day I'm
  • 11:13going to show you something that
  • 11:14says it's not that complicated
  • 11:16because it turns out quite simple.
  • 11:18So the baseline coefficient,
  • 11:21the naive condition, ohh sorry,
  • 11:23baseline naive continuing.
  • 11:25These are the hippocampal
  • 11:27gradients are both of them.
  • 11:29This is the first and 2nd principal gradient.
  • 11:32There's actually a zero
  • 11:33order which is baseline.
  • 11:34Both of them show this AP
  • 11:37effects one is more or less.
  • 11:39To make people and one is anti symmetrical,
  • 11:42and those of us who have done a lot of PC
  • 11:44I know that most often come in like this.
  • 11:47There's a symmetrical effect in the brain.
  • 11:50One mode grabs the symmetrical effect.
  • 11:53There's some sort of asymmetry
  • 11:55left and right aren't saying the
  • 11:58asymmetrical mode grabs that effect.
  • 12:00These are linearly separable
  • 12:01so we add them up.
  • 12:02And then there's some other
  • 12:04joint modes usually.
  • 12:05So one thing that jumps out of this.
  • 12:10This is a critical control.
  • 12:12We had 33 people with mild AD or MCI.
  • 12:17What jumps out of this?
  • 12:20Not much difference, right?
  • 12:22These these conditions very different.
  • 12:25The GLA's were huge,
  • 12:27the gradients are all pretty similar,
  • 12:29and the gradients are pretty similar
  • 12:31in the clinical cohort, however.
  • 12:33Ohh. And then the other thing
  • 12:35you can do is project these
  • 12:37gradients onto the onto the cortex.
  • 12:40This is where Punk gets drilled down here.
  • 12:43I'm going to talk about this later on,
  • 12:45but this is the camel gradient,
  • 12:47this is the cortical projection of that
  • 12:50anterior posterior Campbell gradient.
  • 12:53So not much changes, but what we looked at.
  • 12:57Then to do some contrast,
  • 12:58we looked at this what I spoke about before,
  • 13:01the magnitude of these gradients.
  • 13:03So if the gradient changes.
  • 13:04Very quickly across a few boxes,
  • 13:06we could have a functional
  • 13:08boundary there because we say on
  • 13:10this side of that rapid gradient,
  • 13:11everything's more or less connected
  • 13:13to the same cortical voxels.
  • 13:15We go down and sort of step
  • 13:17and the pattern of whole grain
  • 13:19connectivity changes very quickly
  • 13:21and then it smooths out again.
  • 13:24So we really focused on the
  • 13:26magnitude of the of the gradient.
  • 13:29This is what the magnitude
  • 13:31of the gradient looks like,
  • 13:32even though the algorithm was applied
  • 13:35to very different sort of data.
  • 13:37This is very similar to what we
  • 13:39got out of the resting state human
  • 13:41Connectome project in the hippocampus.
  • 13:43And you can see this step between
  • 13:46the posterior hippocampus and
  • 13:47the head of the hippocampus.
  • 13:49So this is I should have oriented,
  • 13:51this is one and here a view
  • 13:53of the hippocampus.
  • 13:54This is the power of the hippocampus
  • 13:55is the head of the hippocampus.
  • 13:57You get this sharp.
  • 13:59Gradient,
  • 14:00which is consistent with what a lot
  • 14:02of other people have spoken about,
  • 14:03that there is some degree of
  • 14:06functional segregation here,
  • 14:07but it happens on the background
  • 14:09of continuum. So now we can.
  • 14:12We can do some permutation tests.
  • 14:14We can do some contrasts.
  • 14:15We do see differences here.
  • 14:18This is the healthy cohort,
  • 14:19this is clinical cohort.
  • 14:20This is the contrast between
  • 14:22the continuing and naive.
  • 14:24So even though they're basically the same,
  • 14:28these patterns, these gradients,
  • 14:29the magnitude of them does change
  • 14:32across the task and within the
  • 14:34task and across the conditions,
  • 14:37we also see slight differences.
  • 14:40So this is critical code.
  • 14:42Just hopefully control.
  • 14:43You don't see much in the resting state.
  • 14:46I cause cognitive challenge for the brain.
  • 14:49You put in a task and you do see
  • 14:51a difference in the functional
  • 14:53segregation that you would have is.
  • 14:56And that paper?
  • 14:59Published today,
  • 15:00today in a very famous journal
  • 15:04starting with letter end.
  • 15:07You're in French?
  • 15:11This journal you get the very
  • 15:12best reviewers and the best.
  • 15:17OK.
  • 15:22Now this is where I hope
  • 15:24I have a bit of time left.
  • 15:27This is where I started to sort
  • 15:30of really get into this project.
  • 15:35Alright, so this hippocampal gradients
  • 15:38is the cortical projections.
  • 15:39As I've said, they don't change a lot,
  • 15:42not in the magnitude.
  • 15:43They do change a little bit.
  • 15:45But what's going on here?
  • 15:47I started reading about the hippocampus.
  • 15:50When I got the reviewers were the only
  • 15:52and I got the reviewers the idea was
  • 15:55back in Paris with the startup company
  • 15:57I was in in Chile in a hotel room
  • 16:00with all looking at his Python code.
  • 16:03And yeah, this will be this wonderful
  • 16:05literature on the campus and the gradient.
  • 16:07And it's felt that the panel hip
  • 16:10campus is sort of century motor cortex
  • 16:13sort of world centric and the head
  • 16:16of the hippocampus as you can see
  • 16:18here is connected to functionally.
  • 16:21Related with key regions and the
  • 16:23default plan like curious the angular
  • 16:26gyrus anterior called temporal cortex.
  • 16:29This is our default mode or what
  • 16:32people call the allocentric.
  • 16:34It's pretty cool.
  • 16:35Like it's like a it's like a Google map.
  • 16:39The brain,
  • 16:39A1 dimensional Google map of the brain.
  • 16:41You know I wanna go into deep
  • 16:43like breaks here,
  • 16:44go into the head of hippocampus,
  • 16:45have all my autobiographical memories.
  • 16:48I want to go to entirely with hippocampus.
  • 16:50And then they go ohh look I'm in a
  • 16:53room speaking to a bunch of people right.
  • 16:55So if we in this work by
  • 16:58invariant and others,
  • 17:00this is like a cognitive map not
  • 17:02just a spatial topographic map.
  • 17:04It's a cognitive map that somehow links
  • 17:08things in the world between time and space,
  • 17:10and between what's in the world
  • 17:12and what what is in the mind.
  • 17:15So what's the meaning of what's in the world?
  • 17:19So we can just flip the projection
  • 17:22and this is Saturday,
  • 17:25the sensory motor and it's pretty,
  • 17:28it's a bit messy, it's not beautiful,
  • 17:30but these are sort of driving networks.
  • 17:32So attentional networks, yes.
  • 17:34So this is sort of mapping onto
  • 17:37attending the world and the head of
  • 17:40the hippocampus is mapping on to.
  • 17:42What's going on internally?
  • 17:45And this projection, by the way,
  • 17:47is quite a lot rougher and clinical
  • 17:50in the clinical convoy.
  • 17:52OK, so now we're going to tomorrow this.
  • 17:56And I'm going to use what's called
  • 17:58a neuromas or main fuel model.
  • 18:01They're similar but different.
  • 18:02So instead of modeling all the
  • 18:04neurons or even simplified neurons,
  • 18:07I'm going to lump them together
  • 18:08and use very simple, great model,
  • 18:10as it's called.
  • 18:11It's called the Wilson current model,
  • 18:13one of the first neuromas models.
  • 18:16I had the pleasure to be with me,
  • 18:17both Chris Wilson and Howen.
  • 18:20And all that is really doing is the
  • 18:23right of the red exciter is skills.
  • 18:26Going up and then that kicks in
  • 18:29and excites the local inhibitory
  • 18:32neurons that feedback and inhibit
  • 18:35the excitatory cells.
  • 18:37That's like a credit credit predator
  • 18:40prey and not surprisingly you
  • 18:43get oscillations as the exciter
  • 18:45is new population are excites
  • 18:48the inhibitory population.
  • 18:49It is very weird spike phase
  • 18:52delay between private selves
  • 18:54and the inhibitory cells.
  • 18:56And you can then project these
  • 18:59rights back into the neurons.
  • 19:02And this is what the far
  • 19:04and criminal cells reply.
  • 19:05And this is what we're firing
  • 19:07inhibitory cells like.
  • 19:07And we just heard about ripples and
  • 19:10these are like fast ripples that
  • 19:12sit atop these slow oscillations.
  • 19:14And I think this is quite an important thing.
  • 19:17It's a lot of time when I
  • 19:19present neural mass models,
  • 19:20people think it's very abstract.
  • 19:22It's just the right modulation of
  • 19:24the underlying neurons and you can.
  • 19:26Move between two worlds,
  • 19:28but the bottom has got
  • 19:31thousands of degrees of freedom.
  • 19:33The top has got far fewer.
  • 19:35And you can see this slide phase
  • 19:38lag between the pyramidal cells
  • 19:40and the inhibitory cells and
  • 19:42this is an importance with
  • 19:45neurophysiological recordings.
  • 19:46So now I'm going to put these
  • 19:49into the hippocampus with a very
  • 19:51simple way of coupling just
  • 19:54an exponential kernel of the.
  • 19:56Local neuron neural masses interacting
  • 20:00with their neighbors and it's just
  • 20:04going to show this for one reason.
  • 20:07This is space prime plot time space
  • 20:13space for this particular hippocampal bottle.
  • 20:17And this is what it looks like
  • 20:19if we put the hip camps here,
  • 20:22the posterior and the anterior with
  • 20:25this particular semantic kernel,
  • 20:27it's more or less going into this
  • 20:32seizure like coherent state.
  • 20:34But there's a few of these
  • 20:37interesting little Birdy bits which
  • 20:39are quite interesting to me and if
  • 20:42we just focus on them.
  • 20:44We see what's happening here is
  • 20:46there's a bit of a phase between the
  • 20:49excitatory cells and the inhibitory
  • 20:52population and then it reorders itself.
  • 20:54So it's sort of has a little slip.
  • 20:56This is quite common in these
  • 20:58sort of systems.
  • 20:59I've got this neuron from
  • 21:02my friends type of Carmilla.
  • 21:04I actually reviewed this paper and I thought,
  • 21:06well this is pretty cool.
  • 21:07And then working with Matt recently
  • 21:10has reinvigorated my interest
  • 21:12in computation in the dendrites
  • 21:14if the pyramidal cells,
  • 21:15and this is just as high published it,
  • 21:18come into the distal part of the
  • 21:21den tray by the time they get to
  • 21:23the soma and the inhibitory cells
  • 21:25that are projected down here have
  • 21:27had a chance to catch up and that.
  • 21:30Cancels the phase delay.
  • 21:33Which is this EI balance in the
  • 21:36soma until you get this slip,
  • 21:39and then you get a bit of excitation.
  • 21:41In addition,
  • 21:42mismatch and this readout you're on
  • 21:45will then fire the readout you're on,
  • 21:48Simon,
  • 21:48until there's an imbalance between
  • 21:51the excitation and inhibition.
  • 21:52That's how you get from neural
  • 21:55oscillations to some sort
  • 21:56of computational spiking.
  • 21:57OK, Sir,
  • 21:58a few years ago we showed that you
  • 22:02can do these neural mask models
  • 22:05on structural connectivity,
  • 22:07doesn't really matter whether
  • 22:08it's the human Connectome project,
  • 22:10your local diffusion,
  • 22:12reconstructive structural connectome,
  • 22:14you get these beautiful whole brain
  • 22:17waves and Johanna was speaking about these,
  • 22:20but these are really highly
  • 22:22nonlinearly excited waves,
  • 22:24very metastable and these waves
  • 22:26have been published and observed.
  • 22:29In many different species,
  • 22:32many different recordings and
  • 22:34electrophysiological recordings
  • 22:35during imaging recordings recently
  • 22:38so the not controversial.
  • 22:41OK, so now we're going to get waves in
  • 22:44the hippocampus and then I'm nearly
  • 22:45finished and I'm sorry if I'm over time,
  • 22:47but we just changed the synaptic
  • 22:50kernel and you can actually hopefully
  • 22:52see after a little bit of disorder,
  • 22:55you get these diagonal stripes.
  • 23:00And if we run out of all moving forward,
  • 23:02this is the disorganised part,
  • 23:05that of turbulence going on here.
  • 23:07And then all the modes competing,
  • 23:11they're quite excited.
  • 23:12And eventually you get one dominant mode
  • 23:15and this is propagating posterior anterior.
  • 23:20You might think I'm crazy.
  • 23:22I'm not actually.
  • 23:23I read this paper first.
  • 23:25There's a lot of work coming out
  • 23:27now that these alternations be
  • 23:29hippocampus travelling waves.
  • 23:30So here we are with travelling
  • 23:33waves in the canvas.
  • 23:35And now we're going to look at the
  • 23:37interaction between hippocampal waves
  • 23:39and cortical waves in this example.
  • 23:41I haven't coupled them.
  • 23:43Police are getting you to see
  • 23:45hippocampal waves and the cortex
  • 23:47doing its own crazy thing.
  • 23:49Umm. You get the drift.
  • 23:54This is gonna settle down into the waves.
  • 23:57This is not.
  • 23:58This is just doing its own irregular but
  • 24:02quite interesting self organizing patent.
  • 24:08But then we're not. We're going to take.
  • 24:13These gradients, which I think are phase
  • 24:16gradients because you saw that the
  • 24:19functional connectivity was quite strong.
  • 24:21So I think this anterior posterior
  • 24:24gradient is a phase gradient and
  • 24:26it maps onto a phase gradient in
  • 24:28the cortex and lo and behold,
  • 24:31if we just use this map.
  • 24:36You're not going to be surprised.
  • 24:37Might be surprised. We get.
  • 24:44Traveling waves in the hippocampus are
  • 24:47reorganizing what's going on in the
  • 24:50cortex and imposing a wave pattern.
  • 24:52So now we've got waves going from the
  • 24:54tail to the head of the hippocampus,
  • 24:56driving waves going from the sensory
  • 24:58motor to the default mode of the brain,
  • 25:01that this is actually A1 dimensional brain.
  • 25:03So we'll we'll get there.
  • 25:07You see there's a little bit of disorder
  • 25:09here, so there's a few times slips, not many.
  • 25:11But if I then put a bit more
  • 25:15noise into this projection by
  • 25:17the Alzheimer's disease cohort,
  • 25:19you see already there's a lot more noise,
  • 25:22there's a lot more disturbance for
  • 25:24the company is not much less cleaner.
  • 25:32And. Yes, I had to solve this stick together.
  • 25:37I see this is the hope cardboard,
  • 25:40and this is the clinical cardboard in black,
  • 25:43and the hippocampal waves in red and
  • 25:46the cortical waves, and you see.
  • 25:50Just a little bit more disorder in the
  • 25:54cortex and a lot of disorder in the.
  • 25:58In the disease cortex.
  • 26:03Now just to finish. Umm, what's happening?
  • 26:07Every time it hits and creates one
  • 26:09of these spaceships in the cortex,
  • 26:12remember, it's reading something out,
  • 26:14so there's a lot of false, if you like,
  • 26:17read out in the Outsiders disease.
  • 26:20There's a lot of more specific
  • 26:22readout in the healthy,
  • 26:24in the healthy controls.
  • 26:25So that's my theory of the brain.
  • 26:28But I think it's just like a radar.
  • 26:30So if we're walking around daydreaming,
  • 26:32we've got all our hipcamp,
  • 26:33we've got all our cortical waves
  • 26:35doing their crazy.
  • 26:35Meeting but if we need
  • 26:38to recall recent memory,
  • 26:40then we drive the cortex with these
  • 26:44hippocampal waves and we're basically
  • 26:47using HIP campus to read out recently
  • 26:50stored messages in the cortex and
  • 26:52then read out through these space
  • 26:55slips that then trigger an imbalance
  • 26:58in the EI and a little a few spikes
  • 27:02that then represent that retrieved.
  • 27:06And in our side, this disease,
  • 27:09this smooth patterning is disrupted.
  • 27:12So you're getting a lot of false readouts.
  • 27:14Yeah, that's you.
  • 27:16I see.
  • 27:23Our work is there and Andrew,
  • 27:26everything I showed, all those
  • 27:28simulations have done in this financial
  • 27:30toolbox which my former post operate.
  • 27:33You can download them.
  • 27:34You could repeat everything that I
  • 27:36did in this talking about 10 minutes.
  • 27:39This is my fledgling group in Newcastle.
  • 27:42I'm beautiful and wonderful
  • 27:44country and it next time you're in
  • 27:46Australia you must come and visit.
  • 27:48We can go surfing.
  • 27:49It's going snowboarding.
  • 27:51OK. Thank you.
  • 27:58Randy. Interestingly,
  • 28:01the surfing connection package
  • 28:03looking at flowing waves.
  • 28:05Nice connection there.
  • 28:08There is, actually, because
  • 28:10when you're looking at whites.
  • 28:11It was talking to me, Mac.
  • 28:15No borders, right,
  • 28:16they're looking ahead. No, not me.
  • 28:18I've got about A2 metre window,
  • 28:21but you're looking further ahead now.
  • 28:22Wave good surface and the same thing.
  • 28:25They can read the wave 3040 metres
  • 28:27away because they know the reef.
  • 28:29When the wind is coming,
  • 28:30when ocean waves coming and they interact
  • 28:33with the underlying ocean floor,
  • 28:35it causes disturbances.
  • 28:36And that's where this whole
  • 28:38crazy theory of mind came from
  • 28:41here the campus is getting the
  • 28:43brain to scan from back to front,
  • 28:45from sensory motor to default and back.
  • 28:48And all the little disturbances
  • 28:49that were there from a few minutes
  • 28:51ago caused disruptions in the
  • 28:53I balance and get read back,
  • 28:55back into the back, into the hologram.
  • 28:57So sorry right here.
  • 29:02Wait to be phased?
  • 29:05So that makes it more clear with
  • 29:07the theory is I guess the question
  • 29:09I have is the degree to which the
  • 29:12phenomena you're you're modeling is
  • 29:14self organization versus actually
  • 29:16more directed this comes to mind
  • 29:18is our little man sort of pushing
  • 29:20it tends to do that or does this?
  • 29:24Organization emerge naturally
  • 29:25in this always happening by by
  • 29:27the nature of the anatomy of the
  • 29:29function that are that couple.
  • 29:30Well the key thing is in the hippocampus.
  • 29:33The key ingredient I made out of hippocampus
  • 29:36have a slightly slower time scale,
  • 29:37faster than the head of the hippocampus.
  • 29:40But naturally after some disorganization
  • 29:43self organizes into these coherent waves.
  • 29:46The brain is doing its own thing,
  • 29:48the cortex is doing their own thing
  • 29:50until you turn the coupling on
  • 29:51and they're just like the atrium
  • 29:53driving the ventricle of the heart.
  • 29:55The hippocampus drives the cortical waves,
  • 29:59reorganizes them so that they
  • 30:01flow from sensory motor cortex
  • 30:03through to the default mode.
  • 30:05So it is self organising and you just
  • 30:07need a bit of symmetry breaking and
  • 30:09then you can stand back and it all comes
  • 30:12out without being heavily directed.
  • 30:15And it comes back to like Jim was talking
  • 30:18about the the learning, what he called it.
  • 30:24You're essentially modeling what a
  • 30:26complex system adaptive system do
  • 30:27after go through iterations of has
  • 30:29this capacity to explore repertoire
  • 30:32to use the word dialect and you
  • 30:34by by putting the model in there
  • 30:36as it as it moves through time as
  • 30:38the model grows becomes coupled.
  • 30:40It has this natural capacity to
  • 30:42explore and the exploration of lighter
  • 30:44stand your models is driven by at
  • 30:46least coordinated through the caps.
  • 30:48That's the practical importance.
  • 30:51Turning on the right on, yeah,
  • 30:53there's quite a lot of theory that
  • 30:56recent memories are encoded by latent
  • 30:58excitation in prefrontal cortex.
  • 31:00And when the hippocampus
  • 31:01sends the cortical wave,
  • 31:03just like my surfer on the reef,
  • 31:05it disrupts the wave and
  • 31:07it disrupts the phase.
  • 31:08Relationships would be hidden campus that
  • 31:10causes a disruption in the hippocampus.
  • 31:14Yeah, it's. So it's more about scanning.
  • 31:16It's not, this is not a brain exploring
  • 31:18when the hippocampus gets turned off.
  • 31:20That's the sort of daydreaming mode.
  • 31:22But I will say with Tim's talk
  • 31:25for where is Tim is, yeah, look,
  • 31:27the activity is more or less the same.
  • 31:30It's the various relationships
  • 31:32amongst the Pastor networks that are
  • 31:35doing everything that's different
  • 31:37from daydreaming to cognition.
  • 31:39And I think you were saying the same too,
  • 31:41Todd, the activity atop the resting.
  • 31:43So it's not that different, but yeah,
  • 31:47these patterns are different.
  • 31:49Your honor.
  • 31:52Be nice.
  • 31:56And actually there is a study where there
  • 31:59are doing like temporal interference,
  • 32:02you know with our simulation content frontal,
  • 32:05Netherland, posterior part of the campus.
  • 32:10And they find that modulates like
  • 32:13sending their different waves.
  • 32:16In different parts of this campus
  • 32:19modulation different networks
  • 32:20so and in a way also like slide
  • 32:23change of frequency but if the
  • 32:25they were comes descending like a
  • 32:27traveling with the rain and then
  • 32:29will resonate inside of the brain
  • 32:31stretcher and generated this campus.
  • 32:33I think it's a I I really buy this as a as a.
  • 32:38Then there are other structures also
  • 32:40sending different types of sonars
  • 32:42or radars like you're saying for
  • 32:44what type of wave is being sent?
  • 32:46Maybe there are more strangers sites.
  • 32:50It is the alpha, right?
  • 32:53That's the, that's the,
  • 32:54that's what Hansberger described
  • 32:56and we've worked on that before.
  • 32:57That's a different resonant loop.
  • 32:59The hippocampus is more feeder and
  • 33:01then the ripples are top of that.
  • 33:02Yeah. So yeah,
  • 33:04one physicist to the other, yeah.