[HN Gopher] The Roots of Fear: Understanding the Amygdala
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The Roots of Fear: Understanding the Amygdala
Author : birriel
Score : 137 points
Date : 2024-11-04 15:29 UTC (1 days ago)
(HTM) web link (www.ucdavis.edu)
(TXT) w3m dump (www.ucdavis.edu)
| amelius wrote:
| > The researchers took samples from brains of humans and rhesus
| macaque monkeys, separated individual cells and sequenced their
| RNA. This shows which genes are active (being expressed) in a
| particular cell and allows researchers to sort them into groups
| based on gene expression.
|
| How do you extract RNA from monkeys without activating the RNA
| that expresses fear?
| verisimi wrote:
| > How do you extract RNA from monkeys without activating the
| RNA that expresses fear?
|
| You stroke the back of the monkey's hand and give it banana
| treats.
| rawgabbit wrote:
| RNA is the messenger from the nucleus that tells the ribosome
| what to make.
|
| The DNA sequences that create the RNA are called genes. It was
| only learned the last few decades that genes can be turned
| off/on. This is how a single embryo cell can produce all the
| different cells in our body. Unfortunately they chose the word
| expressed for this concept.
|
| What they are saying is they want to study the amygdala aka the
| primitive pre-evolutionary part of our brain we share with
| other creatures. It is said the primitive brain controls
| breathing, heart rate,fear and anger. It is also said emotions
| like fear or anger is our brain's faulty perception of our
| body's response to all the adrenaline the amygdala is
| initiates.
|
| They know the amygdala has different types of cells. To learn
| why certain cells malfunction, and cause depression and other
| disorders, they are studying DNA sequences.
| immibis wrote:
| The RNA doesn't express fear - it expresses that this is a type
| of cell that goes in a certain place in the neural circuit that
| expresses fear.
| wayoverthecloud wrote:
| I think there are two types of fear mostly, the innate survival
| animalistic fear and the self-perpetuating fear caused due to
| misunderstanding. The animalistic fear is present in all and it's
| not possible to get rid of. When you see a snake or a tiger in
| front of you, that fear is natural. The response is to jump or
| run and is so spontaneous, you can't really control it. It's
| necessary for survival. But I think we are interested in the
| other fear, the one that is bound to attachment. You see a tiger,
| you panic, turns out to be a cat, you laugh it off, go away, that
| fear is not an issue. But if you go about your day thinking, what
| if that was a tiger? What if I get jumped by tiger this time?
| Then, you are creating the fear. The fear has no basis, except
| for it was implanted to you awhile ago. And now you are attaching
| yourself to it. You are extending it which is the actual problem.
| Most of us have fears that go back to childhood. If you think
| back far enough(like the tiger example), question yourself why
| you are afraid, you know the answers.
|
| One more example, I used to be afraid of getting heart-attacks in
| the past. Even gas passing would make me panic. Have I ever had a
| heart-attack before? No. How am I so damn sure that I have a
| heart-attack if I don't even know what it's supposed to feel
| like? Heart-attack is a bad thing and it shouldn't be happening
| to me. How is every acid reflux a heart-attack to me now. I have
| created my own bubble of fear. When though? I sure as hell didn't
| know what heartattack is when I was born. So it happened when I
| was able to comprehend what a heart-attack is right? For me, it's
| due to people around me passing, it's due to reading on Internet
| about young celebrities dying to strokes, watching movies, etc.
| It got implanted in me. I don't know a heartattack I just have an
| idea of it which is not the same thing. Not even remotely
| related.
|
| Fear arises due to misunderstanding. If you trace it far back
| enough, fear was implanted mostly in the childhood.
| lloeki wrote:
| > What if [...]?
|
| Sounds more like anxiety than fear.
|
| While fear is happening in the present, anxiety is anchored in
| the future.
| zusammen wrote:
| Anxiety is near future and usually has a specific set of
| possible causes. Dread is more of a far-future, diffuse
| flavor.
| cen4 wrote:
| Its both nature/genes and nurture/environment.
|
| Nature is what you get when you go and buy a new laptop.
| Nurture is what you get after it fills up with shit over the
| years. So you got to be careful about what you install and
| allow in.
|
| Inputs from the Environment the brain is constantly receiving
| changes genes, brain structures and brain chemistry over time.
| You can then pass those changes to the next gen. Media
| ("media"ting Information entering the brain), plays a big role
| in what inputs the brain is getting. Its all around you and
| constantly feeding your brain signals you might not even be
| conscious off. Media also exploits people's Negativity Bias
| which compounds the issue.
|
| So pay attention to what you pay attention too. Divide all the
| info entering into - entertainment, short term value, long term
| value. Filter out everything else.
| jakubtomanik wrote:
| One is a feeling the other is an emotion. It still amazes me
| why, as a society, we keep treating them as the same.
| numewhodis wrote:
| Mostly because it's a multi-dimensional spectrum and because
| exceptions extend the rule and society deals with most
| exceptions via some form of adjustment 'therapy' and that
| requires a framework that the bulk of the people learns to be
| convincing enough so that the exposure effect
| supports/complements the (re-)adjustment.
| numewhodis wrote:
| You can unlearn animalistic fears. And animals, insects (& some
| people to whom it applies) will respond accordingly.
|
| Fear due to misunderstanding is also a bit off because lots of
| happily 'stupid' people aren't afraid, despite self-awareness
| of their misunderstanding.
|
| Fear of heights: Gone after paragliding.
|
| Fear of spiders: Reprogrammed via exposure.
|
| Fear of big & dangerous looking animals: Overcame it by
| training a dog properly - or rather: by training myself to
| train a dog. Posture, tone of voice, controlled awareness
| translate directly via pheromones, audio-visual and 'bio-
| electric' *presence*. And don't be vague, boss. Be precise,
| patient and, again, present.
|
| Fear can be intuition: your cells have memories of their own
| and your DNA goes way back much further than we care to think
| of. Something that will cause lots of fun & pain when LLMs
| start to fuck with us out of curiosity (scripted or not).
| bowsamic wrote:
| You paint the "what if?" fear as if it's completely useless,
| but I think it's important to consider these things and there's
| a reason we consider the alternatives. I don't think that's
| something we should try to get rid of
| tartoran wrote:
| > The animalistic fear is present in all and it's not possible
| to get rid of
|
| It is possible to get rid of this fear with controlled
| exposure.
| Vecr wrote:
| https://gwern.net/backstop#hui-nengs-flag -- Evolution as
| Backstop for Reinforcement Learning -- Hui Neng's Flag -- the
| mathematics of positive and negative reinforcement
|
| https://gwern.net/fiction/batman -- The Gift of the Amygdali --
| Sci-Fi, anxiety, pain
| anodyne33 wrote:
| tl:dr - brains are weird man
|
| There's a tremendous episode of Radiolab called Fault Line that
| talks about the effect of a total resection of the Amygdala. It
| worked out very poorly. I heard it weeks before I was scheduled
| for a right temporal lobe resection, including Amygdala and it
| scared the bejeesus out of me. A quick call to my neurosurgeon's
| coordinator assuaged my fears.
|
| The bilateral resection caused Kluver-Busey syndrome in the
| patient that Fault Line discusses.
| spoonfeeder006 wrote:
| > The researchers took samples from brains of humans and rhesus
| macaque monkeys, separated individual cells and sequenced their
| RNA. This shows which genes are active (being expressed) in a
| particular cell and allows researchers to sort them into groups
| based on gene expression.
|
| Thats (potentially) a lot of neurons to sift through isn't it? I
| wonder what their process was, or how many neurons they can sift
| through. Too bad the paywall (yay for greedy journal institutions
| profiting off the labor of scientists)
| immibis wrote:
| They most likely took a big batch of cells and used some
| chemical methods to separate them into groups, then blended up
| each group and analyzed it.
| richrichie wrote:
| Fear is fundamentally a hardware attribute and not a software
| issue (ie not trainable).
|
| Not showing fear does not mean there is no fear. People train
| hard not to show it. But it is there. Amygdala disfunction people
| are different. That free solo climber is an example. He feels
| nothing.
| 082349872349872 wrote:
| > _not trainable_
|
| Counterexample: crowd-control horses.
|
| [EDIT: we can quibble about terminology; I think it's fair to
| say that while apprehension may always remain, fear, and
| certainly panic, can be trained away]
| guerrilla wrote:
| This is completely wrong, counter to all contemporary
| scientific theories on the subject. Exposure therapy works
| exceptionally well and we know how it works: through
| desensitization. We can measure this in multiple different ways
| including blood-serum levels of various substances, fMRI, HRV,
| etc. The physical evidence for that and how it works is
| staggering.
| fatnoah wrote:
| A recent experience I had came while walking in a forest with
| friends about an hour from Seattle. While walking, we heard an
| animal sound of some kind that cause an immediate "hairs on the
| back of my neck standing" up reaction along with what felt like
| an adrenaline rush (time slowing, narrowing of focus, etc). All
| of this happened immediately, and it took a few moments for my
| conscious mind to catch up. My friend and I looked at each
| other and walked briskly away from the sound. It wasn't until
| we encountered another hiker that we found out a mother bear
| and cubs had been spotted in that area.
|
| This was unlike any other fear of animals, jump scares, or even
| near-miss types of experiences I've had in the past. It was a
| very primal and immediate reaction to a sound I've never heard
| before.
| tartoran wrote:
| > Fear is fundamentally a hardware attribute and not a software
| issue (ie not trainable).
|
| The fun thing is that this hardware we have can be rewired so
| it could be trainable in many instances. Maybe in all of them
| if we only knew how.
| WhitneyLand wrote:
| https://en.wikipedia.org/wiki/S.M._(patient)
| trhway wrote:
| To me very illustrative are the scans here - looks like Honnold's
| visual cortex (lighted up path at/from the back of the head)
| doesn't have [that good] connection to amygdala and thus no fear
| response:
|
| https://nautil.us/the-strange-brain-of-the-worlds-greatest-s...
| aYsY4dDQ2NrcNzA wrote:
| Little-known fact: amygdalae come in pairs. You have two of them.
| endoblast wrote:
| Yes. My knowledge of neuroscience is derived mainly from
| articles like this and popular science books where many things
| are left vague.
|
| If someone has a hippocampus or amygdala damaged or removed
| it's rarely specified whether its the left one, the right one,
| or both. Presumably it matters!
|
| Both the above structures seem mysterious but I understand they
| both evolved from older cortex which sort of curled up over
| evolutionary time. 3-layer cortex rather than the 6-layer of
| the neocortex. I'd be glad to be corrected here.
|
| The amygdala is associated with fear but it's concerned with
| desire too. Unwanted desires can be just as inconvenient as
| unwanted fears.
|
| A classic source of confusion for me is the ubiquitous phrase
| 'brain circuits'. Is this a metaphor drawn from electronics, or
| what? 'Circuit' implies a loop but I assume they're just
| pathways.
| nuancebydefault wrote:
| In origin circ is a loop, but I'm quite sure brain circuits
| is an allusion on electronic circuits[] , which have pathways
| but not necessarily loops.
|
| [] https://www.britannica.com/technology/electric-circuit
| erie wrote:
| I think I got help from studding the experience of the 'anatomy
| of fear' in 'The Emperor Jones', a 1920 play by American
| dramatist Eugene O'Neill. It helped me understand how irrational
| fear would gradually get into me. I was stranded in desert area
| known for hyenas. Walking with a heavy backpack for 7 hours in
| complete darkness to reach the camp, I started 'seeing' things in
| the dark. I started singing first, then praying, couldn't find
| stones to throw at dark spot I though were water ponds formed
| during the heavy rain, I had a break down. Then I saw the lights
| of the camp that showed me how I deviated from the path to it by
| a far margin. But something pleasant happened afterwards, I felt
| I conquered fear and my tolerance for unpleasant things got a big
| boost.
| cnity wrote:
| This is an awesome illustration of character development by
| trial, a thing lost in our modern culture. Thanks for the
| anecdote!
| rbanffy wrote:
| Every time the amygdalae come up, I always point out it affects
| almost all tings human:
| https://academic.oup.com/scan/article/13/1/43/4596542
| HPsquared wrote:
| Reminds me of this classic (funnily enough under the same
| domain) which the Independent linked under an article called
| "Disabling parts of the brain with magnets can weaken faith in
| God and change attitudes to immigrants, study finds":
|
| https://academic.oup.com/scan/article/11/3/387/2375059
| immibis wrote:
| IIRC some study also found that right-wing people have
| noticeably larger amygdalae.
| detourdog wrote:
| Probably from exercising it with anxiety.
|
| I could see how a certain amount of anxiety can develop
| high achievers and too much could develop problems with
| analysis.
| numewhodis wrote:
| > Probably from exercising it with anxiety.
|
| Or empathy with an imaginary self & kin.
| detourdog wrote:
| Doesn't that express as anxiety when the imaginary self,
| kin and reality don't aligh.
| numewhodis wrote:
| Is a lie really a lie when you mean/believe it at the
| time?
|
| Empathy trains the amygdala. So anything that causes
| anxiety in an empathy-trained amygdala 'originates'
| somewhere else, probably via modulation in parts of the
| CNS that deal with the specific stimulus that causes the
| impulse of fear which manifests via stress hormones and
| responses of heart, lung, neurotransmitter producing
| organs that cause muscle tension, (loss or gain of)
| clarity and sharpness of vision and so on.
|
| So your brain perceives something. Or your body does. The
| effect is near instant. What do studies say about small
| and big amygdala people and speed of stress response in
| CNS? I'd have to check ...
| detourdog wrote:
| I never mentioned lying. I believe the anxiety is from
| the confusion. I can understand how empathy can drive
| anxiety.
|
| I have doubts that a person with imaginary self is
| capable of understanding another being well enough to be
| empathetic. I could perceive that the empathy the anxious
| one is declaring is a rationalization to enlist others in
| the promotion of the imaginary self.
|
| Warning my only training in this area is life experience.
| numewhodis wrote:
| The imaginary self is the lie. And so is the perceived
| kinship. Empathy is liminal or a contract with
| conditions. "It's not the dogs fault" doesn't matter when
| he tries to rip off the finger-tip of a stranger who
| smelled like bad intentions. That's why people put dogs
| on leashes and or train them.
|
| You are surrounded by people with imaginary selves,
| usually no more than one or two selves, so it's not
| really pathological and no cause for worry. And we all
| enlist others in the promotion of the in-group, which is
| an agreed upon imaginary construct we call collective.
|
| And you are correct: most of 'them' have no empathy, most
| of them don't understand other beings well enough to be
| empathetic. Think productive people and hustlers and low
| earners who watch more TV than they learn after work.
|
| But anyone understands their perceived kin. Even if the
| kinship breaks. Which brings me to
|
| THE dominating and least perceived anxiety: will they
| betray me?
|
| My partners, my colleagues, my wife, my customers, my
| boss, my government, the person I'm having a random
| conversation with, the producer of drug xyz, that
| salesman, my ISP, that news anchor and all of the
| individuals involved in those teams that make up
| departments and whole corporations and institutions. Will
| someone fuck up? All of that causes a build up of stress
| and, once the individual threshold is reached, anxiety.
|
| But the average threshold is hard to reach because of
| defense mechanisms and compensations. Thus the amygdala
| gets trained and well nourished while the modulators loop
| through rollercoaster after rollercoaster.
| detourdog wrote:
| I can see the false self as a lie but I can also see it
| as misperception of other's intentions.
|
| Developing response from stimulus in one environment and
| blindly applying it in other circumstances I see as
| dysfunction.
| lainga wrote:
| What a fucking website this is! Farewell, cruel dang!
| detourdog wrote:
| I don't understand how faith in g-d could have a universal
| root.
|
| I do think faith could have many roots just like hatred.
| criddell wrote:
| Maybe I misread it, but I don't think it says there's a
| universal root.
| detourdog wrote:
| They seem to claim a universal fix/cure.
|
| I didn't read the link Text I was going by the comment
| that faith in g-d is effected by magnets. I don't believe
| faith is universally derived.
| oigursh wrote:
| During burn out, I had utterly debilitating and constant anxiety.
| My brain was just a dial-tone and I could barely move or think.
|
| Absolutely useless adaptation/response. Just made things worse.
|
| An SNRI completely suppressed it.
| detourdog wrote:
| I'm emerging from a multi decade relationship where my
| partner's anxiety was so extreme it got into my subconscious.
|
| Once I dropped concerns for their anxiety over the course of a
| year I discovered my original personality. I felt this
| personality was slowly degrading as I tried to relieve my
| partner's anxiety.
|
| I feel young again.
| tartoran wrote:
| Empathy has second order side effects I guess. It's still
| better to be able to empathize than not. As a highly
| empathetic person myself, I had no choice but to dial it down
| as I got older. My first instinct at someones' misfortune is
| of course still one of empathy, but then I ask myself if
| there's anything I could do to help, if this person deserves
| it, though it could be an animal in pain. At this point, no
| matter what the answer is, the empathy signal is no longer
| useful, I turn it down all the way, think of something else,
| etc.
| FailMore wrote:
| Dreams and fear have an odd and slightly unintuitive
| relationship. When we are anxious and awake the amygdala is
| active and norepinephrine (the "fight or flight"
| neurotransmitter) is high.
|
| During REM sleep, surprisingly the amygdala is inactive and
| norepinephrine is 85% lower than base waking levels (not high
| anxious levels). So the brain is in a super relaxed state!
|
| I wrote a paper on the implications for dream content and
| interpretation (I'm a psychotherapist in training).
|
| If you're interested you can find the paper here:
|
| https://osf.io/preprints/psyarxiv/k6trz
|
| And it was discussed on HN here:
|
| https://news.ycombinator.com/item?id=19143590
| OhHiMarkos wrote:
| I remember something similar being mentioned in a podcast by
| Huberman, that dreams serve to get used to stuff that we fear,
| in a nutshell. Maybe not directly stuff that we fear, but maybe
| stuff that makes us uncomfortable? Dreams are a way to teach us
| stuff that seem essential to us but we found them uncomfortable
| to face.
|
| Interesting research topic by the way. I will take a look at
| your paper.
| kridsdale3 wrote:
| Like an endogenous version of Ketamine + Exposure Therapy for
| PTSD
| burnte wrote:
| The single most impactful book on my mental health was Daniel
| Goleman's Emotional Intelligence. The Amygdala chapters were
| truly life altering for me in helping me overcome a lot of
| childhood trauma. You learn how that little bit works, and how to
| reprogram it, and it's incredibly powerful. Not easy, but very
| powerful.
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