Session V: Space, Time and Fear: Survival Decisions along Defensive Circuits

welcome back welcome back are you enjoying the soundtrack aren't you from Star Wars to David Bowie thank you thank you it's been put together by the team all right I I personally have been looking forward to this next session which will be Caltech 5 on your slido uh because I think coming back to Caltech for some of us it's Joy but it's also a bit of

fear isn't it Dave zobo a bit of fear and I don't know if any Caltech grads still have dreams where in your dream you still haven't graduated right it's finals week or there's some problems that I think about at Caltech I was a physics major that when I close my eyes and think about them and I think this one is always this bead on a helix

and right the hamiltonian I have no idea what I just said I've blotted out of my mind but I think that you can think of moments of Caltech where we all had quite a bit of fear however this is this is good news because for the elucidation and possibly the healing our next speaker Dr Dean mobs comes to us from the fear Lab at Caltech it

should have its own music Dean is Professor of cognitive Neuroscience Ellen BC and Davis and Lena Bel Davis leadership chair and director of the Caltech brain Imaging Center he's going to help us understand a little bit more about what happens when we respond to fear so please enjoy space time and fear survival decisions along defensive circuits welcome Dr mobs well uh thank you for that wonderful

introduction there I'm not sure I'm going to follow that um the title of my talk um is space time and fear and I'm going to be not talking about that universe that surrounds us but the universe that exists within our skulls and the first talk a little bit about how we go from our sensory phenotypes to this wonderful imagination system that we have this inner eye

that we have and now this is important and when we understand fear in humans I'm talking a bit about the work that we've done on this sort of spatial Temple distance effects upon danger I know this determines our strategies and we talk about some of the work we've done on brain Imaging I'm going to talk a little bit about then about safety perception now this determines

our strategies and then give some conclusions and at the end with a little bit of time I'll just talk about a couple of slides out some of the more recent work that we've been doing on anxiety and social media Okay so as an effective neuroscientist somebody's influenced by the field of Behavioral ecology and evolutionary biology when I see a face like this I see survival phenotypes

okay I see a set of ears okay that allow us to be able to detect the rustle of a potential predator in a bush or the war of a bear or lion in the distance we have a system where we can smell threats as well although the smell or factory system in humans is relatively poor compared to other species we can still smell uh certain animals

particularly for those who have lived locally you probably smelled skunks a few times finally in terms of the face here we think about ourselves as a visual species okay we have this ability to be able to detect threats the distances we have we have the ability to be able to focus in on threats using our visual systems and if we just focus a little bit in

the beginning here on the evolution of the visual system what we see is that in mollusks and other other primitive species is that these species will sometimes have what we call a pigment spot that's a set of visual cells there like detecting cells that are flat and what these cells can detect are shadows if this pigment spot becomes a cup like this all of a sudden

those light sensitive cells can detect lights coming from the left and coming from the right so now the organism can make a decision to either flee from the left or flee to the right as the eye becomes fluid filled we can use refraction to be able to focus that line onto these light sensitive cells okay the retina cells as we call them to be able to

now to get more of a granular view of that stimulus in the environment now we can begin to detect the identity of that stimulus is it a predator or is it a prey and finally when we jump all the way up to our eyes we have two eyes we get binocular vision we can have depth perception we can focus our eyes okay to be able to

separate threats from non-threats in the environment and the moment that we evolved that perception we evolved the ability to see the future okay so here we can see a bear in the distance and the moment that we see a bear like this in the distance we can begin to plan to avoid that swear okay we can strategize avoidance and what's very interesting is in someone's books

is out of the eye and our sensory systems evolved so did the cognitive machinery this Machinery that's involved in strategic defensive responses survival responses also evolved as well we also know that it's not just about how the eye evolve but where it evolved on our ads in some respects if we look at Grays and animals like horses uh sheep cows we see that their eyes on

the side of their head and this is advantageous for survival because now they have almost a 360 degree view of their world and they can detect threats in the environment versus Predators tend to have their eyes more centralized which tells us a little bit something about what we are but what fascinates me as a psychologist and the cognitive neuroscientist is this point in primary Evolution probably

goes back to Homo erectus or before over a million years now but certainly something that we see in IMO sapiens over the last 300 000 years is that we moved from using those sensory systems to detect things in the environment to this inner eye that we have to be able to simulate and predict threats in the future I want to give you a couple of examples

here what's really fascinating about our imagination um one of my favorite philosophers the Scottish philosopher David Doom wrote about the Golden Mountain and what he proposed was that we can all think about a mountain okay we can all think about gold but in our mind in our imagination we can combine them to create a gold Mountain a gold Mountain does not exist in the real world

okay we can use our imagination to create new things about the world we don't have to have an experience through the world we can create them in our minds language plays a role in the way that we perceive the world brittgenstein proposed what we call vickenstein's triangle where he said that if we see an image of a triangle like this we call it a triangle but

if we take that triangle and we call it an arrow it becomes an arrow if we take that triangle and it becomes a pyramid it becomes a pyramid we have this very plastic ability in our minds to be able to perceive the same thing in different ways but also this inner eye this imagination that we have is also important for what we call mental time travel

those you can sit there and you can think about in the moment that your ear in this lecture theater this to this boring talk and then you're um in the present but you might be thinking about the past okay your memories what you did yesterday but also you might use perspection to think about what you're going to do in the future this is important if we

can think about the future we can think about dangers in the future we can avoid them before we actually encounter them one of the most adaptive strategies that any organism can have but importantly I think this gets us in trouble because if we can think about the future and we can think about the dangers of the future we can become anxious about things that have not

existed yet and maybe even anxious about things that may never happen I think that's why existentialists call us an anxious species in some respects so what's this got to do with fear okay well I've alluded to this in some respects but this has got well it's got to do with human fear is that when we study in fear in humans we need to understand really this

Rich internal environment that we have this inner eye okay and now we use it to strategize and simulate experiences with threats okay and also um we worried a couple of years about a couple of years ago about what we really really need to question when we're asking about fear we need to really understand first of all in terms of fear and anxiety and our defensive responses

we need to understand what are the natural conditions that give rise to these emotions okay what are the temple spatial properties of the environment an animal that has evolved in open planes will need much better depth perception to be able to detect threats at distances an animal that's evolved in forests where the leaves and the grass is in its face it's not going to use its

visual systems as much it's going to use other senses more okay it's going to have different defensive responses we also know that animals that are in environments where it's very difficult to predict Predators well typically are things like shells and spikes okay therefore they don't necessarily always have to make a decision under those conditions their physical phenotypes is adapted for them we also need to understanding

as I mentioned the traits of the threat as well is an ambush threat okay is it a fast attacking threat and once you understand these natural conditions we can begin to try and understand the strategies the behavioral strategies that organism makes to avoid or escape from that threat how does it overcome that evolutionary obstacle and once we understand those behaviors we can begin to apply computational

models to understand what is an Adaptive strategy and what is a non-adaptive strategy we can also look then to see how other survival strategies are involved in these or impact or mediate these different strategies so for example a mother protecting its Offspring an animal that is thirsty or hungry will try and suppress some of these Fair responses okay and we'll change its strategies even in the

face of predation so once we understand these two components we can begin to see what parts of the brain or the newer mechanisms that underlie these different strategies and this is sort of the model that we've proposed that we need to really use that when we're designing the experiments to study fear and anxiety in our brain we don't like I should say we don't like to

use those terms fear and anxiety I'll come to that in a minute so what is fear and anxiety well we take very much a dimensional approach okay um as usual Charles down was the first to mention this where he said fear takes the gradation from their attention to extreme Terror and aura but the way that we tend to define fear today is that the motion results

from a presence of an early imminent threat a tangible threat so if there was a tiger in this room now and it was close to you particularly if it was close to you you would be feeling fear But anxiety is associated with stimuli threat stimuli that abstract or distant in time or space so abstract is about the future something that's going to happen fear is about

what's happening now that's the way we Define it okay so all of a sudden you can see within these definitions there's a spatial temporal component to the way we define fear and anxiety so I'm going to show you guys a video now an example of the sorts of questions that we asked this is a gentleman being attacked by a tiger okay nobody dies in this video

okay you don't see the tiger actually bite him but if there's any children in here they might not want to see this um so um this is a tourist filming at the distance okay a tiger this is what we call the Post encounter there's a threat in the environment here there's a again is a threat in the environment he knows the threats there but he doesn't

know that he's under attack okay is this where we get the anticipation is it going to attack or not this is where the inner eye in some respects is trying to work out what the sweat's going to do and what you'll see now is that the Tiger is attacking this is what we call circus strike attack it jumps up and it ends there okay and if

you want to see more you can go to attackfootage.com Okay so a question we have then in my lab is what's happening in this gentleman's brain here when he knows there's a threat in the environment okay he doesn't know he's under attack yet but he's trying to work out he's trying to strategize it's trying to in some respects have a theory of Mind of what that

um tiger is going to do but in the cases first thing I'm going to show you what we're interested in is what's happening in this individual's brain here as the tiger is getting closer and closer and closer still the same tiger okay it's still dangerous but the way that you react to that tiger be able in the brain systems associated with that are different okay and

the vicarious uh sort of learning from this is that the stick is not a great weapon against the tiger all right I grew up in the 80s as you can probably tell I still get on my air that's from the 80s and um and um I was very much influenced by some of the games back then um and we wanted to create a simple task where

subjects were being pursued by a virtue of predator in a virtual environment so we're very much influenced by the game Pac-Man many of you might remember Pac-Man you may be still in Platt stay still in one player so we created a very simple task here and what happens in this task is that the subject navigates this triangle around this maze trying to escape from this virtual

Predator okay if that subject gets caught by the Predator they'll receive one or three electric shock to the back of their round okay I can hear some of you laugh there but they're not that painful okay they're just like pin Pricks on the back of the hand we want them to be aversive but we don't want them to be too painful because they get these repeated

okay but what we're what we're interested in here is what's happening in the brain as that President gets closer and closer to them okay much thought that tiger example I just showed you now there was a model that came out about a year before we started this study back in 2007. and this model proposed that when threats are distant you activate parts of the prefrontal cortex

the hippocampus which is not unable also parts of the basal lateral amygdala that we know associated with strategizing avoidance of threats but as that threat comes close are you shut down those prefrontal cortex systems okay because they're slow you want to react and the hypothalamus and the midbrain Park reductal gray indicated there by pag are associated with that uh fight flight freezing response if you go

into the brain of a rodent and you stimulate these different Columns of the PHD you can stimulate one column for flight response another column for freezing response and so forth okay but the the basic example is it's involved in reactive fear in reacting to the environment not thinking okay what do we see in this uh quite simple experiment here um sorry you guys can't see the

liner there's a line here that an arrow that points to the um Red Dot there but what it's basically showing is that when that dot is distant there's increased activity here in the ventral medial prefrontal cortex much like that model I suggest I showed a minute ago okay and this is involved in more of that strategic response maybe sometimes even that conscious feeling of threat but

as the threat comes close you see a shutdown of that system in the prefrontal cortex and just there you can see it looks like a pair of lips kissing the aqueduct just here it's a blob and you see this switch to these midbrain Parker Dr Gray areas you don't want to be thinking if the Tigers here if you're thinking when the Tiger's air you get eaten

you want to just react okay so this was the first experiment we did this I did this as part of my PhD we wanted to follow this up then um uh with my postdoc where we want to use more realistic um stimulus so you can guess from this what we did we put people in the MRI scanner and we moved a tarantula closer or further away

from their foot or we made them believe that at least so is the individual like is a schematic is actually a real individual and scanner and what we did is we we could decolot space and time here with this task we would move the tarantula in each of these different open top bins closer or further away from their foot okay this is a Brazilian pink salmon

bird eating tarantula okay they're pretty big you can see that's me picking it up there okay when I told the subjects about this task I um I didn't mention the bird eating bit I thought we might scale them so um what we did then is that we put these in the scanner we recorded their brain activity as a tarantula was closer and close to their foot

okay and what we found is that as we see the um trying to move closer and close to their foot there was increased parametrically increased activity in these regions of the midbrain encompassing the power production grade that fight fight freezing system that reactive system okay that increased again as the Tarantulas place close to their foot again this was passive because they couldn't move I made some

nice laughs down there thank you so um what we uh found then was um that when we move the tarantula away from their foot there was increased activity here in the ventral medial prefrontal region now this was interesting because there was some indication from previous research that this Region's associated with safety signals when you're under threat okay on all of a sudden you see a police

officer for example or you've got a weapon or you feel safe that region seems to come online okay it's indicating to you that you're safe I'm going to come back to this in a minute so again we've shown this switch between these midbrain systems and the medial prefrontal cortex but we wanted now to create a tasks where we could look at decision making to fast or

slow attack interrupts so we went back to the ecology literature and there's this sort of famous uh Paradigm out there called flight initiation distance what is flight initiation distance is the distance at which you flee from an approaching threat it's a measure of threat sensitivity okay so in this example a simple example here that when any animal is in the in nature and it's performing some

survival functions okay it's got two um things to consider okay there's the cost of not fleeing so if the Predators there on the environment it fleas too late it's going to be caught by the predator there's also the cost of fleeing if the organism is performing some other survival Behavior mating drinking eating for example if it flees too early it's giving up okay those other survival

functions that it needs to have okay so there's always this balance between fleeing and not fleeing so this is work by sanchi who's now at NIMH doing the postdoc and what we did is simple tasks like this again people in the MRI scanner we have this platform here like this and what happens is is that there's this triangular and the subject compressible in any time for

this triangle to go back to the safety of the exit now the economic component to this task is that the longer they stay in that position the more money they earn okay so there's a motivation for them to stay there then count a number of different Predators there's two of them um what will happen is the Predator will appearium begin to oscillate towards them and at

a certain point it will attack them okay the moment it attacks they get caught they can't escape so they have to make these flight decisions before the threat attacks so they have to learn the statistics of the environment they have to learn that this blue dot is going to attack somewhere within this gaussian and this slow attacking threat is going to attack somewhere within this scale

symbol they never fully unders or know exactly where it's going to attack they just have some estimates but that's on purpose because we want some individual variation in this as well then is that when you're making the decision to flee from this fast attacking threat okay this is going to activate more of those midbrain Park reductal gray fair circuits okay when you've got longer time to

think about that threat that's going to activate more of what we call the cognitive fear circuits but also these overlap with anxiety circuits in the brain which have become obvious in a minute so what do we find again when they're making a faster decision to escape from that threat midbrain power conduct a great comes the line but also Parts the mid-singulate region which we know is

highly connected to this region of the midbrain areas okay and again as the midbrain regions are involved in Flight decisions this argument that this input coming from the mid-singlet region we can see just here may be associated with adaptive control of that behavior okay it controls when they're going to flee and we run some computational models to support that which I'm not going to talk about

now but when they're making a decision to flee from the slower attacking threat now they've got more time to think okay different region comes online still the same threat still the same amount of shocks they get if they get caught but now they've got more time to think okay medial proof in the cortex hippocampus comes online this may be associated with more of that kind of

strategic escape from that threat epic campus more information processing particularly in the context of they're trying to probably they're probably trying to remember where that threat attacked them before they're trying to remember in a conscious way okay so our argument then was well if anxiety if you need time to become anxious it's a slow process we should only see those anxiety circuits come online when they're

making a slower decision okay and that should correlate with individual variation in what we call trait anxiety it's a questionnaire that measures individual variation in trait anxiousness and that's what we find so what we find is that for the slow attacking threat the more anxious they are the later they will flee from that threat okay oh sorry the earlier they will flee from that threat we

find that for the fast attacking threat track anxiety doesn't correlate it with within at all okay so anxiety does not correlate with fear when we look at the correlation between the neural activity in the brain and trait anxiety individual variation in it we don't see anything for the fast attacking threat but for the slow attacking threat we see the classic anxiety circuitry the hippocampus and the

Venture media Improvement of Cortex along with the insular are increasingly active the more anxious you are and the connectivity or couple in between these two regions is strengthened by the more anxious you are and there's work by Josh Gordon I know this has shown this in rodents as well that this is more that anxiety is associated with the connectivity between these regions okay so um the

sort of last thing I'm going to talk about is safety perception and this is a new study that we're not published yet uh where we looked at what we call adaptive safety coding okay so many of you remember last year at the Oscars that there was this individual um Will Smith and Will Smith um was offended I'm not going to promote his his violence at all

but he was offended what was said to about his wife by this individual Chris Rock so what's going on when he's angry and decides to go onto the stage and slap Chris Rock okay what's going on is first of all is looking at Chris he's upset of course but it's making also a judgment about safety and threat if I go on stage and attack this individual

okay is smaller than me okay so I value him as not being as threat in him and if he does fight back I'm bigger than him and I can handle it okay so there's two things going on there's the characteristics of the threat itself and the metacognitive ability to know if that person fights me I can win the fight okay but you could argue that if

it had been the rock rather than Chris Rock he probably wouldn't have gone and slapped him around the face okay that wouldn't have happened because he all of a sudden he realizes that the threat value and the ability to handle that threat and combat has changed and I love this study that came out or just a survey here you've probably seen it yeah um if you

ask Americans and British the likelihood of winning a fight against different animals you see differences so two percent of British people believe they can win a fight with a grizzly bear six percent of Americans believe they can this doesn't change guerrillo's Lions elephants two percent of British are still pretty high but eight percent of Americans believe they can win a fight with an elephant that's great

so we were inspired by that of course we always look for good ideas and and that's the foundations I think to good science but we did a simple task here what happens here is that you're given a threat stimulus like this where it's an extreme threat seems like a bear or a lion to a bird and a cat and and questions can we win a fight

with each of these different stimuli have these all raided online and so on but you're always paired up with a weapon as well so it could be a fist it could be a stick or it could be a gun or grenade okay so what happens in this task is Give an example there's your your given a picture of the um Lion Air and you said we

win or lose that fight with that lion and then what happens is there's a short break here this is in the scanner again and what happens is is that you're given the best weapon okay so all of a sudden this is no longer really a threat okay or it's less of a threat I'll show you the probabilities in a minute so you're more likely not to

get a shock if these two are paired but you can actually have it where it could be the lion you have the uh you have the fist so you're more likely to get a shark or it could be the grenade goes first or the stick goes first and we have all the different permutations of this we scanned each subject for over two hours each to get

a lot of Trials here so hopefully you guys can see that from there but I'll explain it so what happens if you get the grenade yeah there's a 50 chance of winning a fight with a bear if you get the grenade there's uh nearly a 57 chance of winning the fight uh with the with the lion 85 chance of winning the fight with a bird and

93 chance of winning the fight with the cattle though I'm not sure what kind of people would use a grenade against a cat well not surprisingly what you see down here is the subjective win this is their um ratings of their likelihood of winning the fight and you can see here that when they've got the fist the worst weapon they can have and the bear they

rate their likelihood of winning being much lower than if they're given the grenade and they're fighting the cat okay and you see that this was 100 subjects online where they lost money and this is 30 subjects in the MRI scanner here at Caltech and we replicate these effects but what do we see in the brain this preliminary evidence we're still going through this data but what

um we looked at here was what's the difference if we look at the line I'm going to give you a simple example we've got the lion okay this is the second stimuli and we've got the Lion Air but the difference between these two conditions here is that this one was preceded with a fist a bad weapon this one was preceded with a grenade a good weapon

yeah to beat that animal okay what do you see if it's a fit the line is followed by fist okay you're likely to receive an electric shock then what you see is that the insular midbrain pag regions just here you can see is the aqueduct there come online okay if it's a grenade then you've got the lion okay then you see this ventral medial prefrontal region

I just talked about that's involved in these safety signals comes online now we did a meta-analysis a couple of years ago where we looked at all the studies that looked at safety and what we found is clustering that when subjects are given safety signals this region in the anterior I mean anterior means the front part of the proven the court has come online but threat signals

okay seem to come on more in the posterior the back part of the prefrontal cortex here and again this is that region that we saw for the tarantula as it's moved away in another study we showed that when you're shown a DOT that indicates that you're going you're not going to receive an electric shock this region comes online when it's predictable it's easy to predict a

threat in the environment this region comes on versus less predictable in our margin of safety task is another group from UCLA Naomi eisenberger's group that when we've shown a loved one a picture of a loved one when you're about to see a shock this region comes on Lime as well so this is sort of a new region that we think that's important and trying to understand

where what might go wrong in individuals with anxiety disorders because most of the research so far is focused on which I've not talked about today but also this posterior region but nobody's really studied that region so conclusions fear and anxiety this sort of dynamic process involved in the complex defensive circuits distal distant slow gradual threat is associated with this cognitive fear circuit through this anxiety circuitry

including the Venture media prevent cortex among other regions hippocampus and parts of the lateral amygdala proximal close or fast attacking threats seem to be push the activity in the defensive response to these midbrain regions involved in reactive fight flight freezing systems motor circuits and as I've just shown the anterior part of the prefrontal cortex seems to be associated with these safety signals suggesting that there may

be a new region that we can Target in individuals with anxiety disorders what I've not shown is some of the work that we've shown at this our other brain switches between these different systems and a paper we have under review at the moment shows this seems to be in the hypothalamus so supporting the work by David Anderson here and others showing that the switching between survival

States seems to be in the hypothalamus I want to finish up just um the last couple of minutes here with some of the work that we've been doing on what we call the new ecology the Ecology of social media and this is funded by Bill and Sonia darindo who of um Davido who have um support this research in my lab and we're just starting to get

some data out of this now is Bill's book I recommend reading it if you're interested in the future of society in the relationship between machines and what we know is that with social media that since it began there's been this gradual increase in depression in boys and girls and this seems to correspond with the increased use and instigation of social media okay and we see a

bit of a jump here in particular in the time when we begin to see likes and retweets going on and I have a daughter I of course adore very much and she's going to want to go onto social media in the next three or four years yeah I don't want to call it at all but she's going to be asking to go on it and I

want to figure out ways in which she doesn't go out into this Wild West of social media which is unconstrained okay and that we begin to get policies maybe but also we begin to get training procedures in place to get these children prepared for going into this wild west of online social media again let's go back to this model that I talked about earlier that when

we're trying to understand okay any phenomenon particularly in the field I work in in terms of fear and anxiety we want to understand the natural conditions and we've proposed in a paper that we're currently writing that if we break down social media there's a number of different components to that environment that are different from the way that we communicate face to face when we communicate online

Things become disembodied okay um there's no longer that physical barrier there that physical boundary between me and you talking okay I'm using internal dialogue to communicate with you I have impaired influence because I'm not seeing what your face looks like when I'm communicating with you okay so all of that disembodiment starts this process rolling there's also a lack of accountability okay with the avoidance of legal

and moral Norms okay if we particularly for anonymous okay we can say whatever we want it doesn't matter we can say what we're thinking okay and this results in disinhibition yeah that if there's no consequences to behavior okay if I'm disembodied I'm not face to face with you I could say it whatever I want and you're not going to punch me in the face yeah so

I've lowered self-control more moral outrage or outrage rage in general to what you're saying and if you have this this can start this environment become begin to start these toxic online environments and if everyone feels like us everyone's under the same situation it begins to start this roller coaster this Snowball Effect of these toxic environments so we're working from this sort of this set of boundaries

here to try and understand what is the environment then build up from there about how this affects people's behavior and some data that I literally just got emailed me from my students yesterday was looking at these individual variation in trade anxiety remember we talked about this a few slides ago on the hippocampus prefrontal cortex are associated with this threat sensitivity what we find is individuals who

score why on trait anxiety each daughter is an individual by the way they show a preoccu preoccupation with social media they check their social media more subconsciously what that means is you guys have probably done this you've got your social media and then you put your phone down next thing you know your phone's in your hand and your social media media again you're not sure how

you got there yeah um but also these individuals got eye on track anxiety or more stress when they don't have access to the internet so this drive to be on social media the more anxious you are okay but when you look at mood those individuals who score lawyer on try anxiety say that their mood is decreased they have more negative mood when they've been on social

media so there's this drive to go on social media but you feel worse about it when you've been on it okay it's interesting we're going to replicate this on the much this is on over 100 subjects we're going to run this on the larger sample we're running these experiments in the MRI scans see what happens in your brain when you feel uh anxious um when you're

interacting with others online okay so I want to thank you all um for staying around for this talk and I want to thank all of my colleagues here over the years um Demus has had a good Google deep minor friend long-term friend of mine collapse still a collaborator helped with some of the early stuff on on fear and then my lab here at Caltech particularly song

I talked about song and Bowen's work Sarah's work on the safety and swagian Cat's work on the social media I just presented my former Lab at Columbia who contribute contributes on this work my former PhD supervisor Christopher and Ray Dylan and all of my collaborators over the years thank you thank you so much for that fascinating talk oh my goodness the questions are buzzing so I'm

going to take them one at a time um I think Ryan um has asked we hear about sensory systems that create fear responses what about fear that is self-generated I I imagine threats nightmares PTSD do these involve the same or different brains yeah no I think I see that as um uh um as as internally instigated in some respects that we can imagine threats that we

may encounter but there may not even be a threat we can exaggerate those threats in our mind and it's understudied in terms of how our brain uses imaginations in our in some respects to create these fears that are not real fears in themselves okay and PTSD occurs of course due to some to some um external threat of course but it only occurs in about 30 of

people 20 to 30 people who have experienced a traumatic event experience PTSD what is it about those 70 80 of individuals who don't get PTSD we don't know you know why some people talk about it's the reconsolidation the memory that if you there's one study that if you give people like Tetris straight after a traumatic event and they're not consolidating that memory associated with the threat

that they show a decrease in their PTSD um but it's still ongoing you need to keep the mind busy and distract you um in those situations in PTSD in particular yeah yeah another question was sort of in that field Could This research have any relevance to training for law enforcement or the military were extremely consequential decisions have to be made under duress it's interesting I've got

a friend who's doing work on this in the police force in the Netherlands using a task um where they use VR and uh there's an individual who's either got a cell phone that goes like that or a gun and you have to um shoot them in the VR system and they're using this to train the police force to not make reactive decisions in terms of um

uh you know shooting people if they lift their hand up and it's a cell phone they accidentally shoot them or something um and it's the the reactive system that we have is quick and dirty it's it doesn't think too much but most the time that women are under threat like an officer is under threat and thinks somebody's got them they have to react they don't have

time to think this may come down to some form of recruiting there's some nice workout there on Apache helicopter pilots in the military and what you find is they score very very low um on neuroticism which is a sort of indirect measure of anxiety because you don't want to think if you're having to make those quick decisions you uh you want to make quick decisions but

you don't have to think about them versus me if I was out to make those decisions I'd be like oh do I do I do that or not you know if you do that you you'll get shot or you know the the person who was going to kill someone is gone you have to make quick decisions so you can train people on that but our plastic

is that reactive system we don't know how can you train that reactive we can train your slower cognitive system you know that's what therapy does yeah but the reactive system how do you train someone that's so innate and reactive that's non-thinking we think that it trickles down but you have to go for a lot of training to do that becomes what we call model free there's

so many questions right in in this space so I'll just end with one why is it easier for some individuals and this is to mentally overcome their perceptions of fear than others can you define what is going on in a hero's mind here it's difficult it's the way you appraise the situation there's work on Courage that shows that that Venture that posterior part of the Venture

when you breathe from the cortex I talked about comes online uh when you're controlling a snake coming close or further from you and scanner that was a nice paper out of Israel we couldn't have done that study here by the way we wouldn't we wouldn't get it from the ethics um but um tarantula okay that was in England where they really can win against a grizzly

bear I guess we don't know the answer that's it's a great it's a great question yeah I can speculate but there's not really much research out there on that there is a connection a curiosity about uh it's a former participant of extreme sports I'd like to ask why is thrill seeking so addicting so I guess those are a pleasure connection the near-miss effect is is interesting

in that context where um well I think first of all let me take a step back control plays a big difference if you practice a lot and you feel that you're in control then you down regulate those fear systems maybe that safety signal system we don't know yet becomes more active and um and then at the same time we know that particularly during a lot of

these threats the dopenergic systems come online as well which is rewarding you know there's opioid systems avoiding a threat and learning called a prediction error threat activates the dop energy reward areas so I think there's definitely something a little bit strange about humans that we do that but I think that there's definitely a biological basis to that that seems to be in his opioid and and

dopenergic systems in the brain but you know um I give this example the dip what's the difference between your I'm talking about in your brain the the sensory information that you get the difference between when you're on a roller coaster that simulates a car crash and it's exciting your sensory system is getting the same information that you know there's chaos going on but you feel in

control you feel safe um versus you know if I told you then that of the track at the end is missing and we can't stop it that experience in that moment is exactly the same but the perspective nature of the danger that's coming becomes panic and those systems no longer come online so there is a cognitive function to this and we see that even in things

like the placebo effect they're just perceiving something as a sugarpill but perceiving that as a medication can down regulate your pain systems in your brain so the power of the Mind Over these systems is is is is really amazing one other question in this category yeah coming soon to the fear Lab at Caltech the roller coaster and then it's missing um it was recently reported that

people tend to wildly overestimate their ability to land an airplane in an emergency is there any evolutionary advantage to being so arrogantly overconfident um have you ever heard the Darwin Awards like where like these are the people who receive overconfident the ones who said they could win a fight with a bear um we can learn from their mistakes you know there's a vicarious learner if someone

else has suffered a fate of making that mistake we can learn through stories and it teaches us not to do that so that's the advantage probably not to them but certainly to us so a question that I think everyone has been asked has been liked and everyone is thinking to end on perhaps um uh What attracted you to studying fear and anxiety reactions Dr Robbins well

I think it's interesting story in science that you start doing one thing and then just ideas emerge and then this snowball effects so I'll come up with this idea I'd watch this I'll talk about this so if you get to my website where I watch this saw with me I'm a big zombie movie fan yeah I always have been since I was about 10 I shouldn't

have been watching their movies then but I was and um and the a classic thing they do in horror movies is you've all seen this where the monsters come in and you know the the the victim is trying to get the key in the door yeah and the monster's getting closer you know and then the music and Jaws is classic for this Jaws is that ramping

up a looming yeah that looming sounds and it's getting closer and closer we know looming activates the migliff just looming sounds activate the amygdala um so this is interesting because I had a friend who was studying the placebo effect and I was like yeah but what happens like in these are movies where the threat comes closer or further I'm not interested in the pain bit where

it gets you I'm interested when the threats here versus is anyone's sitting there like no but there's some work there's some theories out there and I'm like oh so I came up with the idea of this simple Pac-Man experiment yeah to test this first of all and and then all these other ideas just rolled off of that and and it just took me down that road

and let it take you where it takes you and it's been wonderful yeah you know I really enjoyed it [Applause] and thank you Paul Lee for mentioning about to have you studying the level of fear of anxiety for Caltech students before a final thank you for that thank you so much thank you quite Unforgettable the cat and the grenade okay we will take a quick break

again we'll see you back right at the at the hour the next hour for our final presentation electrified synthesis of molecules