The only thing I've ever been in contact with according to your context has been "the effect of amygdala defect on sensing fear emotion". Unfortunately, my quick search in Google Scholar didn't provide a congenital case for this subject. Perhaps you can perform a more thorough search.

See the work of Michael Davis at Emory Universoty

Michael Davis has never published anything along those lines.

Perhaps a broader more theoretical question should be asked: How does the brain recognize certain things (like cat odor or the sight of a snake) as being fearful without any training? Is this a 'labeled line' phenomenon in which a specialized receptor (e.g., in olfactory nerve) connects to specific circuits that mediate fear? OK, but how then to explain our ability to fear / loathe (or be attracted to) certain things in the visual domain?

I forget who did those studies, they were after world war II.... Look at cats and rats/mice raised together.

http://25.media.tumblr.com/tumblr_luu0tnolef1qgukumo1_400.jpg

The real question is, what is innate?

That's not an empirical question.

Not congenital, but potentially relevant:

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0023277

What clear evidence exists for "innate" species-specific responses for visual stimuli in vertebrates; mammals? (outside of the spider/snake preparedness studies in monkeys, for which I believe there are alternative interpretations).

Which brain structures would mediate such responses. Superior colliculus is a contender, based on studies of receptive-field properties, it doesn't seem to have what it takes.

First of all, I would like to say "greetings" to my fellow Americans in the National Security Administration. Thanks for joining us.

The clearest evidence I could cite off the top of my head is sexual orientation. Heterosexual men use female images (real and otherwise) for arousal, homosexual men use male images. Who taught us to prefer one visual configuration vs. another? I would argue that somehow the brain automatically or instinctively appraises those particular visual configurations in a sex-specific and (usually) adaptive manner.

Or think of the near-ubiquity of certain reptilian images in mythology and horror movies. I'm thinking of the alien in Alien, with its mouthful of teeth, or the snake in the garden of eden, or King George slaying the dragon, etc. The prototype seems to be a reptilian like head with lots of teeth, and that perhaps moves in a slithering manner.

The toxoplasma gondii studies would point to the amygdala (what else?!) as the site of this hypothesized template, since the infection of that parasite preferentially targets the rostromedial temporal lobe, and animals with that infection lose their fear of natural predators.

Greetings!

Although relevant evidence, ideally I'd like to see studies with stimulus-naive animals showing preferences. Otherwise the situation still seems confounded to me.

Although we're not explicitly taught to prefer some images over others, in many ways we might be "taught" by observing other people's reactions or by being exposed to certain images of "attractive people" in certain contexts where they are valued. Or we might not be taught socially, but by direct experience and inference from observing that people who look certain ways might have other characteristics as well (e.g. youth, strength, health, confidence).

Or with respect to the near-ubiquity of reptillian images, that could also be interpreted in terms of individual/cultural learning, or just a reliable inference that big teeth have potentially unpleasant affordances.

Amygdala seems like it would be a key place to look for templates (particularly olfactory). But I still wonder the extent to which genes are able to innately specify responses to particular visual stimuli.

Exactly -- that's the issue. How could genes specify responses to particular visual stimuli. And its a tough one to answer. But there are other examples that animals come into this world with a "readiness" to respond to particular stimuli. I'm thinking of an experiment done with artificial bird beaks painted with a particular dot on the undersurface... chicks seemed to instinctively peck at this dot, which encourages regurgitation of food by the parent. Or the ability of supernormal stimuli (such as extra large crests on male birds) to be unusually effective at attracting mates. Seems like those visual preferences must have some sort of "genetic" component.

But to return to my first example -- sexual orientation. If learning and/or implicit inference plays a role, how then do you explain homosexuality? Why would someone in this culture (or any culture) be apt to display behaviors and visual preferences exactly opposite to those s/he's been "taught"? Moreover, if we form our preferences by observing that people with certain physical characteristics are also young, strong, etc., where does this preference for youth, strength, etc. come from? The answer would seem to promote an infinite regression unless you posit some sort of adapted psychological mechanism that instills a preference for those things without learning.

I could see genes pulling off sensitivity to a color stimulus as in the red-dot-beak example. With regards to preferring large crests, I wonder whether its merely a matter of the inherent impressiveness of a large thing being present at approximately eye-level, resulting in increased arousal responses of all kinds. I'm not so sure about things like .7 hip-to-waist ratios.

Homosexuality is difficult to explain with learning/implicit inference, but I can think of a few different means by which it could be learned. It doesn't seem like Bem's theory was ever debunked, but that it was found to be insufficient for explaining all of human sexuality, which is a lot to ask of a single model. There's also Pfaus' idea that "the first cut is the deepest," where whatever gets there first, strongest, sets up the first attractor networks to colonize that young/plastic brain. And there may also be flipped olfactory biases, which may have extensive innate bases with the some 400 genes for odor components, which can be expressed to varying degrees to increase/decrease sensitivity. And as Kohl suggests, this could be a primary reinforcer that provides salience to visual cues through conditioning. So it seems like many pathways could lead to similar orienting endpoints without relying on biases for highly specific/complex visual stimuli, for which it is still unclear to me what sort of mechanisms could work to implement the biases.

I'm not averse to psychological adaptations, but I tend to have a default assumption of higher specificity/complexity being less likely. Fitness cues could be learned through cultural evolution (which is fast and flexible) and group selection (which I believe to be more powerful (particularly in humans) than commonly assumed), or through the simple inference that more health/vigor is more better (which doesn't really need to be taught except through experiencing the limitations of being an embodied agent). So in many cases it seems that the regress could bottom out with inferences regarding the affordances of different kinds of embodiments.

Interesting stuff, Adam. I'm not aware of Pfaus's model. What is it?

I tend to largely agree with you; I find it difficult to imagine how biology could induce the development of a visual template, but at a loss as to what the mechanism could be, either for innate fears or innate attractions.

Pfaus' provides a good summary of his work in his recent Archives review:

http://www.ncbi.nlm.nih.gov/pubmed/22402996

(Although I said that Kohl thought olfaction is the key primary reinforcer utilized by evolution, he specifically singles out pheromones; if I were him, I'd hedge my bets (particularly considering the vestigial status of the vomeronasal organ in apes…) and broaden the model to include all olfactory stimuli, including sex-specific chemical cocktails, such as aromatic/volatile peptides.)

Well you know that I've been around the block a few times with Jim Kohl on sexnet, and I remain very skeptical about the plausibility of that scenario: olfactory conditioning during infancy leading to selective visual preferences for certain parts of the body; I'm curious what you've thought about those go-'rounds.

I'm also skeptical of the "evolvability" of that mechanism due to its highly fallible nature. Moreover, as I asked on s.n., could the CS be a non-erogenous part of the body? If not, why not?

Mice lacking the neurod2 gene seem to be less fearful - http://www.pnas.org/content/102/41/14877.full

Cool. Thanks Kyle!

I'm agnostic about Kohl's model. I could see odorants acting as a US, perhaps through a GnRH pathway, but like you, I'm not convinced that they are necessary for the development of sexual preferences. Although I'm open to them playing an important role, I don't know whether or not this is the case.

It seems like non-erogenous body parts could become sexual CS, as in the case of foot paraphilias, but in general this would be less likely.

To take breasts as an example, I can think of many non-olfactory-based learning explanations for why they come to be preferred relative to other body parts.

There's nursing, which could implement an imprinting-like mechanism. But the learning could also take place post-infancy.

There's the fact that they're sexually dimorphic in a way that allows for rapid discrimination of potential competitors from potential mating partners, which is salient.

There's their characteristics as semi-pendulous high-sensitivity organs, which may cause women to cary themselves a certain way and relate to themselves in a way where they unconsciously (and sometimes consciously) broadcast (obviously to different degrees in different circumstances, depending on motivation) the importance of those particular body parts.

There's the fact that they are actually erogenous zones, which means that their sensitivity should be discovered by general purpose learners as they interact with the intent of generating maximum arousal in each other, which is itself arousing, and motivation for repeat-performances.

There's the fact that women with larger breasts may have higher estrogen/progesterone, and perhaps greater arousability, particularly around ovulation. This would both feed into the above dynamics where breasts become symbolic of sex, as well as sexualize the women with larger breasts, which would feed into the above stated dynamics even more, which will cause even greater sexualization, etc. These women might breed more with fitter men, resulting in fitter offspring, and hence should change gene frequencies on the population level in a way that would lead to further sexual dimorphism.

So even without smell, all of these things should be reliably learnable on the individual level, as well as by society, eventually achieving totem-like status as symbolic for sex itself. Other parts of the body would be less likely to have these properties.

Although exceptions are potentially telling, such as with foot paraphilias. On the one hand, feet are particularly odiferous, which could be viewed as support for the centrality of smell in sexual learning. On the other non-olfactory hand/foot, there's the theory of cross-wirings between feet and genitalia on the sensorimotor strip, and the theory of young children having relatively high exposure to feet by being at ground-level. Or, we could speculate that feet are treated similarly to erogenous zones in certain ways, since they are often covered up and are given a special hygienic status that would prime our body integrity/contamination schemas that may overlap with sex-related networks. Lots of speculations come to mind, but what's interesting about foot-preferences and other paraphilias is that they seem to point to "basic" learning processes as sufficient and potentially necessary mediators for the development of preferences.

Kyle Wilson's comment parallels research that I have been working on which indicates that Neurod6 and another similar factor, Bhlhe22 are both critical to development of the Basolateral nuclei of the amygdala and innate fear. C-fos is also positively identified with normal development of innate fear mechanisms. You may want to search Newton S. Canteras for his work on identification and manipulation of animal behavior in response to natural predators. Many early developmental connections to the amygdala have been identified originating in the primary sensory areas, especially the olfactory tubercle, and the forebrain as well which are associated with innate fear or aversive responses. Disrupting the factors that guide these connections could and occasionally have been shown to diminish the unconditioned response to these stimuli. In organisms where this occurs through spontaneous mutation, though, the organisms would not seem very likely to survive to be discovered or produce progeny.

I'm curious why individuals with such mutations are unlikely to be discovered or be fertile. Is this because you would expect the mutations to be so much more basic as to disrupt other basic wiring in the brain?

Actually, the supposition is that an animal without innate fear is less likely to survive to reach sexual maturity, as it would not exhibit aversive behavior in situations where danger is faced. This is only a guess on my part.

I remember an experiment where a mouse was put in cage with a cat. The cat hit the mouse couple times then ate him. However, when they tried the same experiment with a mouse injected with testosterone (or equivalent), the mouse did not fear the cat. The cat was terrified at that point. Hope this would help!

We are investigating the neural basis of innate fear behavior. As a innate fear stimulus, we use the odor (urine sample) of carnivores. We are convinced that these stimuli really innately induce fear because the animals (rats, mice) never had same experience with it (in contrast to the absense of thigmotactic cues, bright light, etc., which is also often used). In our experiments, we very often find individual animals having no innate fear response. This can be by chance but could also be due to a genetic mutation/variation. We never investigated this. However, Rainer Landgraf (MPI Psychiatry, Munich), as well as others, selectively bred animals which are extremely low or high fearful in his fear test. His group already identified several genes leading to no/low or high fear/anxiety.

Look, Bradley, newborns and adults have startle reflex, i.e. they tremble when they perceive an intensive stimulus. So, a person deaf from her birth will never fear intensive sounds.

Richard G Coss did some interesting work on anti snake behavior in California ground squirrels. In looking at six genetically distinct subpopulations, some of which had lived in rattlesnake country for millennia, he found that even lab reared squirrels from snake country knew what to do when confronted with a snake, while naive squirrels who came from snake free areas were completely clueless and would have met with a bad end had the snakes not been suitably contained during the experimental exposures.

In snake country, the squirrels had to defend their nests. They would vocalize, flag their tails back and forth and kick sand at snakes. Naive squirrels would wander right up to a snake even after the snake has tried to strike. Squirrels that know snakes will recognize the threat, but if they do not know snakes, they do not know to be on guard. A relevant stimulus is necessary for this kind of study. Good luck! It is an interesting topic.

@ Elizabeth - Cool answer! Now, if they could only find the genes that distinguish those groups on the basis of their behavior ... or perhaps they have?