Animals and the amygdala

As part of a cool project in blogging on Google+ ("plogging"), Nature editor Noah Gray writes about a recent experiment that found that specific neurons in the human amygdala respond instantly to images of animals. These responses were stronger and faster than when other neurons responded to those images, and stronger and faster than when the animal-centric neurons responded to other types of images.

The amygdala is well known to be involved in fear modulation and memory, as well as influencing other types of emotional processing. So is it expected that cells in this structure would respond so strongly to the sight of animals? There is a moderate precedent from the non-human primate literature. Studies in macaques have revealed strong firing of amygdalar neurons to faces, so categorical responses aren't unique in the amygdala. This is true in humans as well, but humans also maintain a different dedicated brain region for face processing, perhaps opening up some portions of the amygdala to take on additional, different roles. But why would we need a dedicated system for animal imagery, elevating this particular stimulus to such an important position in our recognition system? Well this is all speculation, but it isn't difficult to state the obvious and stress that animals were critical as prey for our ancient ancestors, as well as potential threats. Thus, early man may have developed a system to speed our reaction times to such an important category as the landscape was visually scanned for information. Placing this system in a brain region critical to emotion processing could have also more-easily mobilized action through a rapid activation of attack or flight responses.

Image: Animal Kingdom Sign, a Creative Commons Attribution Share-Alike (2.0) image from pixeljones's photostream


  1. Screw the science – I want to visit that Animal Kingdom place!!

    What is it? We can only guess. A pet store? A strip club? Some kind of crazy restaurant? We may never know.

    1. It’s a pet store in Chicago.  On Streetview you can see it’s right next to Kurowski’s Sausage Shop, which might come in handy in any number of ways.

    2. It was a pet store here in Chicago, they closed down a few years back. The building is gone now and is a parking lot. 

      1. Wow! Now THAT was a pet store!

        FTA (No Joke): The [store’s] regular house pets were joined by monkeys, tigers, a llama, exotic birds and even a small elephant called Little Audrey. [Owner] Bernie Hoffmann became famous for bringing Little Audrey and other animals on “Super Circus,” which aired in the 1950s.

      2. Yep, it’s the parking lot for Kurowskis. The sausage hasn’t been the same since Animal Kingdom closed. ;)

    3. Notice how the dog is running away from the Animal Kingdom on that sign.  The mystery deepens.

      Nice, Sean Rafferty gets his comment in right before me, leaving me look the fool.

  2. Kitteh!

    Or, as my wife says about almost all talks on evolutionary psychology, “They’re going to find some way to blame this on tigers again.”  (Usually she’s correct, though sometimes they blame lions or snakes as the animal hiding in the bushes that’s going to jump out and kill you if you didn’t see it, leaving the over-twitchy apes that imagine tigers when they’re not actually around alive to be our ancestors.)

  3. Here is a data point. I was having an emotional roller coaster of a week – family fueding, money issues, and general demotivation. Some racing thoughts and even a rare panic attack. Then I went to my local Ag Fair over the weekend and spent about 20 minutes hanging out with a cow, and suddenly, quite suddenly, almost with a whooshing noise accompanying it, I had some proper perspective which I had been lacking as my week degraded. It was remarkable, and cathartic.

    1. It’s remarkable the calming effect that animals can have on human beings. I get the same from my two cats. When I’ve had a really rough day or am struggling with Depression, just being around them calms me down and lifts my mood.

      I love coming home to find them waiting at the door, doing that little paw-stomping dance of happiness that cats do sometimes. That never fails to make me smile.

  4. There are precedents in non-primate animal studies, too (not that primate people ever read those, *sniff*).  I forget the specifics, but something on the order of rat amygdala neurons firing like crazy for snake pictures.

    This result is interesting but not really surprising.  The amygdala is commonly thought to be all about fear/emotion, but it’s really more like a basic attention and behavior organization module for creatures whose brains evolved before the innovation of frontal cortex and other thinky bits.  Any stimulus likely to activate basic prey or predator-evasion behaviors will show up in the amygdala before it’s processed by any cortical neurons that aren’t doing primary sensory work.

  5. But seriously, now I’m wondering if the Toxoplasma gondii works its magic by doing something to the amygdala. The magic it does is make rats and mice less fearful of cats. It has effects on humans as well.

  6. Yes, but is it the thing responsible for why I clap loudly at wild animals when I want them to get away from me?  I was just talking with a friend this afternoon about how I remember seeing an opossum stick its head out from under our house when I was a kid.  I was about 10 feet away, laying on the grass, and did not want it anywhere near me, so I sat up and clapped at it.  We got to talking about why the human response to animals that you want to get away from you is to clap at them…that seems like an odd instinctual response, doesn’t it?

    Now, if only I could train myself to say “Bravo!” as I do it…

  7. I understand food animals but cats, big cats, have been our number one predator for hominids in our evolution – so why the hell do we think they are so beautiful?   I mean I am entranced by them, visiting a sanctuary the cougars WANTED my two year old and I could hear their excited uttering, they kept their eyes on him, and yet this dangerous animal is gorgeous, not repellent at all.   Weird combo of knowing the danger to my child and yet being able to observe the beauty, why is that (is it thrill seeking through visual stimuli)?   We don’t do the same thing (most of us don’t) with snakes and bears or wolves…

  8. sweet. this now helps me avoid the (suicidaly docile) animal most likely to kill me in my daily life: deer. 

    if i go to the zoo and see a giant/dangerous predator, i’m thinking “that’s cool that i get to see this beast up close (also, it’s kind of sad that it’s in captivity, but is it’s life worse than in nature where other predators or lack of resources might… fuck, i’ve ruined the zoo again…)”

    when i’m driving almost 80 miles an hour down the rural highway on my way to work and i see a deer, i’m slamming on my brakes, my heart is pumping, and i’m thinking “oh shit, that stupid fucker is gonna dart in front of my car because it’s startled, then it’s gonna freeze in front of me and we’re both gonna die.”

  9. Thus, early man may have developed a system to speed our reaction times to such an important category as the landscape was visually scanned for information.

  10. I have very sad news… The Animal Kingdom is no more.  It’s been torn down and replaced by a parking lot.  I have gone there many times for parrot treats after feasting at the Polish buffett just up the street,  Czerwone Jabluszko, aka The Red Apple.   

  11. Seems to me this is a good explanation for the visceral reactions some people have to insects, spiders, snakes, etc. I used to think the phobias were connected to the fact that these creatures are so different from primates. But what if we are hard-wired to have an aversion to, for example, snakes? This has fascinating implications for the Christian portrayal of the devil. There are many interesting aspects of Christianity that emerge from or are a reaction to paganism. But what if the creation of the Devil is directly and intimately tied to genetic survival mechanisms? Is this more or less what “The God Gene” is about? I’ll have to read that.

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