July 21, 2015
Clever crows
This is a pretty remarkable achievement, not just for the crow, but also for the researcher figuring out how to elicit such clever behavior. [1]
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[1] Perhaps the iconic "clever girl" line from Jurassic Park was not, in fact, that fanciful. If some birds are so clever, and since birds are just the branch of dinosaurs that happened to survive, it seems entirely reasonable that some dinosaurs were also quite clever.
posted July 21, 2015 09:21 AM in Obsession with birds | permalink | Comments (0)
July 04, 2013
If birds are this smart, how smart were dinosaurs?
I continue to be fascinated and astounded by how intelligent birds are. A new paper in PLOS ONE [1,2,3] by Auersperg, Kacelnik and von Bayern (at Vienna, Oxford and the Max-Planck-Institute for Ornithology, respectively) uses Goffin’s Cockatoos to demonstrate that these birds are capable of learning and performing a complex sequence of tasks in order to get a treat. Here's the authors describing the setup:
Here we exposed Goffins to a novel five-step means-means-end task based on a sequence of multiple locking devices blocking one another. After acquisition, we exposed the cockatoos to modifications of the task such as reordering of the lock order, removal of one or more locks, or alterations of the functionality of one or more locks. Our aim was to investigate innovative problem solving under controlled conditions, to explore the mechanism of learning, and to advance towards identifying what it is that animals learn when they master a complex new sequential task.
The sequence was sufficiently long that the authors argue the goal the cockatoos were seeking must have been an abstract goal. The implication is that the cockatoos are capable of a kind of abstract, goal-oriented planning and problem solving that is similar to what humans routinely exhibit. Here's what the problem solving looks like:
The authors' conclusions put things nicely into context, and demonstrate the appropriate restraint with claims about what is going on inside the cockatoos' heads (something we humans could do better at in interpreting each others' behaviors):
The main challenge of cognitive research is to map the processes by which animals gather and use information to come up with innovative solutions to novel problems, and this is not achieved by invoking mentalistic concepts as explanations for complex behaviour. Dissecting the subjects’ performance to expose their path towards the solution and their response to task modifications can be productive; even extraordinary demonstrations of innovative capacity are not proof of the involvement of high-level mental faculties, and conversely, high levels of cognition could be involved in seemingly simple tasks. The findings from the transfer tests allow us to evaluate some of the cognition behind the Goffins’ behaviour. Although the exact processes still remain only partially understood, our results largely support the supposition that subjects learn by combining intense exploratory behavior, learning from consequences, and some sense of goal directedness.
So it seems that the more we learn about birds, the more remarkably intelligent some species appear to be. Which begs a question: if some bird species are so smart, how smart were dinosaurs? Unfortunately, we don't have much of an idea because we don't know how much bird brains have diverged from their ancestral non-avian dinosaur form. But, I'm going to go out on a limb here, and suggest that they may have been just as clever as modern birds.
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[1] Auersperg, Kacelnik and von Bayern, Explorative Learning and Functional Inferences on a Five-Step Means-Means-End Problem in Goffin’s Cockatoos (Cacatua goffini) PLOS ONE 8(7): e68979 (2013).
[2] Some time ago, PLOS ONE announced that they were changing their name from "PLoS ONE" to "PLOS ONE". But confusingly, on their own website, they give the citation to new papers as "PLoS ONE". I still see people use both, and I have a slight aesthetic preference for "PLoS" over "PLOS" (a preference perhaps rooted in the universal understanding that ALL CAPS is like yelling on the Interwebs, and every school child knows that yelling for no reason is rude).
[3] As it turns out these same authors have some other interesting results with Goffin's Cockatoos, including tool making and use. io9 has a nice summary, plus a remarkable video of the tool-making in action.
posted July 4, 2013 08:07 PM in Obsession with birds | permalink | Comments (2)
August 20, 2008
Welcome to the club, Magpie (Pica pica)
The past 20 years have already been a humbling experience for people sympathetic to the idea that humans are unique among animals. For many years, it was thought that tool use was an exclusive trait of humans, but then the evidence rolled in that other primates routinely use tools. The real shocker, of course, is that some birds also use tools [1]. And so it also went for cultural knowledge , long-term planning behavior, creativity, and dreaming. All of these behaviors are seen not just in other mammals, but in some species of birds. All this evidence makes it increasingly difficult to argue that there is much fundamentally special about Homo sapiens, except perhaps the coincidence of all of these behaviors in a single species.
To this list of human-like behaviors that birds exhibit, it seems we can now add self-recognition, at least for the European Magpie (Pica pica) [2]. This idea is usually illustrated by the so-called mirror test [3]: some kind of mark is placed on an animal in a spot they cannot normally see (on their chin, forehead, etc.), and a mirror is then placed so that they can see the mark on themselves. The usual interpretation of the resulting behavior is that if the animal recognizes themselves in the mirror, they will scratch directly at the foreign mark that they cannot normally see [4]. This kind of mirror use is seen in all the great apes (humans older than 18 months, bonobos, chimpanzees, organutans and gorillas), dolphins, killer whales and elephants.
Of course, we still have no explanation of what allows such mirror-recognition to happen. Is it the size of the brain alone? (Probably not, but size is likely important in some ways.) Is there some special structure in the brain that mediates it? (Maybe. It would be interesting to stick some of these animals into a CT scanner while they're doing this test to see if there are homologous regions of the brain that light up.) Etc. One thing that's interesting about this new discovery of self-recognition in Magpies is that these birds are in the corvid family, which includes other clever birds like crows. This group of birds are fairly large, and thus have relatively large brains, so it may be that whatever neurological structures facilitate self-recognition, they require relatively large masses of neurons. From a more general perspective though, it's exciting that all of these "complex" behaviors appear in birds. Because their brains are structured quite differently from mammal brains, it suggests that there's not one single way to create "intelligent" brains. If it turns out that there are many many ways to create complex behavior, then perhaps one day we'll figure out what the essential structures and dynamics are, and be able to build one from scratch.
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[1] This is pretty clearly a case of convergent evolution, since surely not all of the interceding species between birds and mammals were also tool users.
[2] H. Prior, A. Schwarz and O. Güntürkün, "Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self Recognition." PLoS Biology 6, e202 (2008).
[3] The mirror test has, in fact, been heavily criticized for its indirectness and its bias toward human-style self-recognition. Of course, as anyone who's encountered the mind-numbing stupidity of corporate customer service, it can be extremely difficult to judge from behavior alone whether an animal is actually a thinking being. Examples abound of humans fooling ourselves and each other on this issue. If you ever want to experience this difficulty first-hand, try discussing with someone else whether your subjective experience of the world is similar or different from theirs.
[4] The control for this kind of experiment is to use two different color marks, one that is flesh- (or feather-)colored and one that is not.
posted August 20, 2008 07:56 AM in Obsession with birds | permalink | Comments (0)
June 30, 2008
More familiar than we thought
The nearly 10,000 living species of birds are amazingly diverse, and yet we often think of them as being fundamentally different from the more familiar 4000-odd mammalian species. For instance, bird brains are organized very differently from mammals -- birds lack the neocortex that we humans exhibit so prominently, among other things. The tacit presumption derived from this structural difference has long been that birds should not exhibit some of the neurological behaviors that mammals exhibit. And yet, evidence continues to emerge demonstrating that birds are at least functionally very much like mammals, exhibiting tools use, cultural knowledge , long-term planning behavior, and creativity among other things.
A recent study in the Proceedings of the National Academy of Science (USA) adds another trait: sleeping [1,2], at least among song birds. By hooking up some zebra finches to the machinery usually used to measure the brain activity of sleeping mammals, Philip Low and his colleagues discovered that song-bird brains exhibit the same kind of sleeping-brain activity (slow waves, REM, etc.) normally seen in mammals. The authors avoid the simplistic explanation that the cause of this similarity is due to a shared ancestry, i.e., mammalian-style sleep evolved in the common ancestor of birds and mammals, which would be about 340 million years ago (with the origin of the Amniote class of animals). This hypothesis would imply (1) that all birds should sleep this way (but the current evidence suggests that it's only song-birds that do so), and (2) that other amniotes like lizards would have mammalian-like sleep patterns (which they apparently do not).
So, the similarity must therefore be an example of convergent evolution, i.e., birds and mammals evolved this kind of sleep behavior independently. The authors suggest that this convergence is because there are functionally equivalent regions of mammal and bird brains (a familiar idea for long-time readers of this blog) [3] and that these necessitate the same kind of sleep behavior. That is, song birds and mammals sleep the same way for the same reason. But, without understanding what mammalian-like sleep behavior is actually for, this could be mere speculation, even though it seems like it's on the right track. Given the other similarities of complex behavior seen in birds and mammals, it's possible that this kind of sleep behavior is fundamental to complex learning behaviors, although there could be other explanations too (e.g., see [3] below). At the very least, this similarity of behavior in evolutionarily very distant species gives us a new handle into understanding why we, and other species, sleep the way we do.
Update 30 June 2008: The New York Times also has an article in its science section about this phenomenon.
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[1] "Mammalian-like features of sleep structure in zebra finches." P. S. Low, S. S. Shank, T. J. Sejnowski and D. Margoliash. PNAS 105, 9081-9086 (2008).
A suite of complex electroencephalographic patterns of sleep occurs in mammals. In sleeping zebra finches, we observed slow wave sleep (SWS), rapid eye movement (REM) sleep, an intermediate sleep (IS) stage commonly occurring in, but not limited to, transitions between other stages, and high amplitude transients reminiscent of K-complexes. SWS density decreased whereas REM density increased throughout the night, with late-night characterized by substantially more REM than SWS, and relatively long bouts of REM. Birds share many features of sleep in common with mammals, but this collective suite of characteristics had not been known in any one species outside of mammals. We hypothesize that shared, ancestral characteristics of sleep in amniotes evolved under selective pressures common to songbirds and mammals, resulting in convergent characteristics of sleep.
[2] New Scientist has a popular science piece about the PNAS article.
[3] Mammals and birds have another important convergent similarity: they are both warm-blooded, but their common ancestor was cold-blooded. Thus, warm-bloodedness had to evolve independently for birds and for mammals, a phenomenon known as polyphyly. One interesting hypothesis is that warm-bloodedness and mammalian-like sleep patterns are linked somehow; if so, then presumably sleeping has something fundamental to do with metabolism, rather than learning as is more popularly thought. Of course, the fact that the similarity in sleeping seems to be constrained to song-birds rather than all birds poses some problems for the metabolism idea.
posted June 30, 2008 08:52 AM in Obsession with birds | permalink | Comments (2)
May 17, 2008
A vending machine for crows
I can't say that I was all that impressed with Joshua Klein's TED talk itself, but the idea of being able to use crows' intelligence and tenacity to produce interesting new behavior is a neat one. For instance, I kind of liked the vision of a murder of crows cleaning up the streets in exchange for peanuts... Plus, the footage he shows of clever crow behavior is worth watching the rest of the talk.
posted May 17, 2008 10:11 PM in Obsession with birds | permalink | Comments (0)
August 25, 2007
Clever, clever bird
Those clever clever crows. Not only can they use pieces of wire as tools to get food they want, but they can use pieces of wire to get other pieces of wire to get food they want! And what is this behavior called? Meta-tool use, obviously.
This fact makes me more convinced than ever that after we humans wipe ourselves out, crows are going to take over as the dominant species on the planet... forget Planet of the Apes, it's going to be Planet of the Crows. (via NewScientist)
A. H. Taylor, G. R. Hunt, J. C. Holzhaider and R. D. Gray, Spontaneous Metatool Use by New Caledonian Crows, Current Biology in press (2007).
p.s. In other news, I quite like the two recent studies that appeared in Science last week showing that researchers can induce out-of-body experiences in normal people using a trick of virtual reality (via Nature News and NYTimes. The scientific conclusion is that these experiences are some kind of hallucination of the mind, brought on by a confusing set of sensory inputs or a misprocessing of existing inputs (or both), and not evidence of a soul or anything supernatural. They have yet to explain why this kind of confusion often happens during brain death, but we'll have to wait for a fortuitous stroke or tumor to figure that out.
posted August 25, 2007 02:53 PM in Obsession with birds | permalink | Comments (0)
March 12, 2007
Avian apprenticeships
Add to the list of amazingly human-like behaviors that various birds exhibit the act of apprenticeship. New research shows that unrelated manakins engage in cooperative courtship displays where the beta male doesn't get any action as a result, but learns the tricks of a good courtship display so that he can become a successful alpha somewhere else. So, in addition to the many other reasons why cooperation might emerge (many of which have game-theoretic explanations), we can now add training for future dominance. Fascinating. From DuVal's conclusions:
Lance-tailed manakin courtship displays are long and complex, and interactions with experienced males may be a critical component of learning display behavior. In accord with this hypothesis, beta males are generally younger than their alpha partners. Consistent performance of courtship displays with a successful alpha partner may allow betas to develop effect and appropriate displays that enhance their subsequent success as alphas. In systems such as this, in which factors other than kinship select for complicated cooperative behavior, long-term strategies to maximize future fitness may depend on social affiliations that reinforce the evolution of complex social structure.
E. H. DuVal, Adaptive Advantages of Cooperative Courtship for Subordinate Male Lance-Tailed Manakins. The American Naturalist 169, 423-432 (2007).
(Tip to Ars Technica.)
posted March 12, 2007 01:22 AM in Obsession with birds | permalink | Comments (0)
February 24, 2007
Time traveling birds
If anyone still needed to be convinced that birds are strange, strange creatures - creatures bizarrely capable of much of what we consider to be inherently human behavior - they need only grok the recent collapse of the Bischof-Kohler hypothesis [1] (tip to New Scientist). Of course, if you're like me, you hadn't heard of the B-K hypothesis previously, and its collapse would have gone completely unnoticed except for my ongoing fascination with bird brains. In a brief letter to Nature, four experimental psychologists describe a simple experiment with western scrub-jays (Aphelocoma californica). The experiment [2] regulated the amount of food available to the jays in the evening and the mornings; on one morning, the jays would be given no food, but on the previous evening they were given more food than they needed. The jays spontaneously and consistently cached some of that extra food for the following morning, when they would be hungry and without food. The researchers say,
These results challenge the Bischof-Kohler hypothesis by demonstrating that caching on one day was controlled by the next day's motivational state and available resources.
So, we can now add time travel to the growing list of human-like behaviors that birds seem to exhibit (others include rudimentary language, basic knowledge of the integers, creativity, tool use, object permanence, cause-and-effect, and that most human of behaviors, deception). I also find it interesting that birds typically only exhibit one or a few of these abilities, suggesting not only that they are located or controlled by different parts of their brains, but also that they are not all essential to survival. It certainly wouldn't surprise me if these behaviors turned out to be a lot more common in the animal world than we give them credit.
Update, April 3, 2007: Carl Zimmer writes in the New York Times Science section about different kinds of time-traveling behavior in several species (including rats, monkeys and humans), and writes at length about the scrub jay's abilities. He also blogs about his article and links to some of the recent science on the topic. End Update
Raby, Alexis, Dickinson and Clayton, "Planning for the future by western scrub-jays." Nature 445 919-921 (2007).
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[1] The Bischof-Kohler hypothesis says, in short, that the ability to (mentally) travel in time is uniquely human. It's clear that humans can do this because we talk about it all the time - we can call up vivid, episodic memories of past experiences or make complex plans for future contingencies in a way not reminiscent of operant conditioning. Since animals can't talk to us directly, we can only hope for indirect evidence that animals can (mentall) time travel. There's some evidence that primates can time travel (for instance), but since they're our cousins anyway, perhaps that's not too surprising. Given the complexity of their behavior, I imagine that elephants would also pass the time-travel test.
[2] I find it amusing that the researchers called their experiment "planning for breakfast," but maybe that's because normally scientific prose is so filled with jargon that a completely sensicle and common name for a scientific term seems like a bolt out of the blue.
posted February 24, 2007 08:37 AM in Obsession with birds | permalink | Comments (0)
January 27, 2007
Fish are the new birds?
Given my apparent fascination with bird brains, and their evident ability to functionally imitate mammalian brains, imagine my surprise to discover that fish (specifically the males of a species of cichlid called A. burtoni) employ similar logical inference techniques to birds and mammals. The experimental setup allowed a bystander cichlid to observe fights between five others, through which a social hierarchy of A > B > C > D > E was constructed. In subsequent pairings between the bystander and the members of the hierarchy, the bystander preferred pairing with the losers in the hierarchy, i.e., near E and D. The idea is that the bystander is hedging his bet on where he stands in the hierarchy by preferring to fight losers over winners.
One interesting implication of this study is that logical inference - in this case something called "transitive inference", which allows the user to use chains of relationships to infer additional relationships that shortcut the chain, e.g., A > B and B > C implies A > C - maybe have evolved extremely early in the history of life; alternatively, it could be that the ability to do logical inference is something that brains can acquire relatively quickly when natural selection favors it slightly. In the case of the cichlids, it may be that the development of transitive inference evolved in tandem with their becoming highly territorial.
I wonder what other cerebral capabilities fish and birds have in common...
L. Grosenick, T. S. Clement and R. D. Fernald, "Fish can infer social rank by observation alone." Nature 445, 429 (2007).
posted January 27, 2007 12:43 PM in Obsession with birds | permalink | Comments (2)
January 16, 2007
Big brains and bird brains
How did I become so fascinated by bird brains?
Last week, NewScientist posted an interesting article describing several recent studies on birds and brains. The hypothesis that both studies consider is whether larger brains offer a particular evolutionary advantage for birds.
In the first, Susanne Shultz and her colleagues in the UK considered whether large-brained birds are better able to adapt to the changing environmental conditions induced by human farming activities than their small-brained cousins. It turns out that it's not just having a big brain that helps birds here. Instead, it's having a big cerebrum - that part of the brain that is overly developed in we humans.
Although their study is purely empirical, there are some interesting theoretical questions here. For instance, past studies on the decline of farmland birds succeeded only in pointing out that so-called "generalists" fared better than "specialists." This distinction is one I've encountered before in the ecology literature, but it's never very well defined. Is it possible to come up with, perhaps from first principles, a reasonable quantity that captures the notion that species vary in how specific their needs for survival are? Humans, for instance, would seem to be generalists, but are we more or less general than ravens? Until we have such a quantity, the question of, for instance, whether humans or cockroaches are more general, doesn't make any sense. But, such details haven't stopped some scientists in the past, and it doesn't stop Shultz et al. from suggesting that bigger cerebrums correlate with more generalist behavior, and that explains why these bird species are able to adapt to changing conditions.
In summary, our results suggest that the farmland birds whose populations have suffered most under agricultural intensification are those with more specialized resource and habitat use and lesser cognitive abilities.
The work of Sol et al. (the second article) seems to support this idea, however. They consider whether larger bird-brains correlated with a higher degree of success in the colonization of new areas. The impressive thing about this work is the extent to which the authors try to control for other factors that might misleadingly give the appearance of a correlation between brain size and success. (This kind of careful statistical analysis makes their conclusion - that big brains help - all the more persuasive.)
Our findings support the hypothesis that large or elaborated brains function, and hence may have evolved, to deal with changes in the environment... [The many hypotheses to the origin of large brains] are essentially based on the same principle, that enlarged brains enhance the cognitive skills necessary to respond to changes in the environment...
The fact that their results suggest such a connection seems to contradict the idea that in order to be successful, an invading species must fit into a previously unexploited niche or out compete previously established species. That is, here, successful species adapt to their new environment by figuring out ways to get food, avoid becoming food, and reproducing. I'm not sure this kind of argument applies beyond higher vertabrates, though. What's missing, it seems, is some kind of theoretical explanation that connects brain size with adaptability. Of course, such a theory would itself depend on knowing what exactly brains do and why making certain parts of them (i.e., the cerebrum) bigger seem to improve one's ability to do certain things.
Shultz et al. "Brain size and resource specialization predict long-term population trends in British birds." Proc. Royal Society B 272, p2305-2311 (2005).
Sol et al. "Big brains, enhanced cognition, and response of birds to novel environments." Proc. National Academy of Science USA 102 (15), p5460 (2005).
posted January 16, 2007 01:29 PM in Obsession with birds | permalink | Comments (0)
January 02, 2007
One brain, two brains, Red brain, blue brains.
Brains, brains, brains.
How do they do that thing that they do?
One of my first posts here, almost two years ago, was a musing on the structure and function of brains, and how, although bird brains and primate brains are structured quite differently, they seem to perform many of the same "high cognitive" tasks that we associate with intelligence. Carrion crows that use tools, and magpies with a sense of permanence (my niece just recently learned this fact, and is infinitely amused by it). From my musing in early 2005:
So how is it that birds, without a neocortex, can be so intelligent? Apparently, they have evolved an set of neurological clusters that are functionally equivalent to the mammal's neocortex, and this allows them to learn and predict complex phenomena. The equivalence is an important point in support of the belief that intelligence is independent of the substrate on which it is based; here, we mean specifically the types of supporting structures, but this independence is a founding principle of the dream of artificial intelligence (which is itself a bit of a misnomer). If there is more than one way that brains can create intelligent behavior, it is reasonable to wonder if there is more than one kind of substance from which to build those intelligent structures, e.g., transitors and other silicon parts.
Parrots, those inimitable imitators, are linguistic acrobats, but are they actually intelligent? There is, apparently, evidence that they are. Starting in 1977, Irene Pepperberg (Dept. Psychology, Brandeis University) began training an African Grey parrot named Alex in the English language [1]. Amazingly, Alex has apparently mastered a vocabulary of about a hundred words, understands concepts like color and size, can convey his desires, and can count. (Pepperton has a short promotional video (3MB) that demonstrates some of these abilities, although her work has been criticized as nothing but glorified operant conditioning by Noam Chomsky. Of course, one could probably also argue that what humans do is actually nothing more than the same.)
How long will it be, I wonder, before they stick Alex in an MRI machine to see what his brain is doing? Can we tell a difference, neurologically, between operant conditioning and true understanding? Can an inter-species comparative neuroscience resolve questions about how the brain does what it does? For instance, do Alex's cortical clusters specialize in tasks in the same way that regions of the mammalian brain are specialized? I wonder, too, what the genetics of such a comparative neuroscience would say - are there genes and genetic regularoty structures that are conserved between both (intelligent) bird and (intelligent) mammal species? Many, many interesting questions here...
[1] Sadly, I must admit, what brought Alex to my attention, was not his amazingly human-like linguistic abilities. Rather, it was an article in the BBC about another African Grey named N'kisi, who has been used to try to demonstrate telepathy in animals. N'kisi, trained by an artist Aimée Morgana, has a larger vocabulary than Alex, and also seems to have a (wry) sense of humor.
In the BBC article, there's a cryptic reference to an experiment that apparently demonstrates N'kisi's talent with language. But, a little digging reveals that this experiment was actually intended to show that N'kisi has a telepathic connection with Morgana. And this is what got the BBC to do an article about the intelligence of parrots, even though the article makes no overt mention of the pseudo-scientific nature of the experiment.
posted January 2, 2007 09:48 AM in Obsession with birds | permalink | Comments (0)
April 30, 2005
Dawkins and Darwin and Zebra Finches
As if it weren't already painfully obvious from my previous posts, let me make it more obvious now:
Salon.com has an excellent and entertaining interview with the indomitable Richard Dawkins. I've contemplated picking up several of his books (e.g., The Selfish Gene, and The Blind Watchmaker), but have not ever quite gotten around to it. Dawkins speaks a little about his new book, sure to inflame more hatred among religious bigots, and the trend of human society toward enlightenment. (Which I'm not so confident about, these days. Dawkins does make the point that it's largely the U.S. that's having trouble keeping both feet on the road to enlightenment.)
In a similar vein, science write Carl Zimmer (NYTimes, etc.) keeps a well-written blog called The Loom in which he discusses the ongoing battle between the forces of rationality and the forces of ignorance. A particularly excellent piece of his writing concerns the question of gaps in the fossil record and how the immune system provides a wealth of evidence for evolution. Late last year, this research article appeared in the Proceedings of the National Academy of Science, which is the article which Zimmer discusses.
Finally, in my continuing facination with the things that bird brains do, scientists at MIT recently discovered that a small piece of the bird brain (in this case, the very agreeable zebra finch) helps young songbirds learn their species' songs by regularly jolting their understanding of the song pattern so as to keep it from settling down to quickly (for the physicists, this sounds oddly like simulated annealing, does it not?). That is, the jolts keep the young bird brain creative and trying new ways to imitate the elders. This reminds me of a paper I wrote for my statistical mechanics course at Haverford in which I learned that spin-glass models of recurrent neural networks with Hebbian learning require some base level of noise in order to function properly (and not settle into a glassy state with fixed domain boundaries). Perhaps the reason we have greater difficulty learning new things as we get older is because the level of mental noise decreases with time?
posted April 30, 2005 04:15 AM in Obsession with birds | permalink | Comments (0)
February 03, 2005
Our ignorance of intelligence
A recent article in the New York Times, which is itself a review of a review article that recently appeared in Nature Neuroscience Reviews by the oddly named Avian Brain Nomenclature Consortium, about the incredible intelligence of certain bird species has prompted me to dump some thoughts about the abstract quality of intelligence, and more importantly, where it comes from. Having also recently finished reading On Intelligence by Jeff Hawkins (yes, that one), I've returned to my once and future fascination with that ephemeral and elusive quality that is "intelligence". We'll return to that shortly, but first let's hear some amazing things, from the NYTimes article, about what smart birds can do.
"Magpies, at an earlier age than any other creature tested, develop an understanding of the fact that when an object disappears behind a curtain, it has not vanished.
At a university campus in Japan, carrion crows line up patiently at the curb waiting for a traffic light to turn red. When cars stop, they hop into the crosswalk, place walnuts from nearby trees onto the road and hop back to the curb. After the light changes and cars run over the nuts, the crows wait until it is safe and hop back out for the food.
Pigeons can memorize up to 725 different visual patterns, and are capable of what looks like deception. Pigeons will pretend to have found a food source, lead other birds to it and then sneak back to the true source.
Parrots, some researchers report, can converse with humans, invent syntax and teach other parrots what they know. Researchers have claimed that Alex, an African gray, can grasp important aspects of number, color concepts, the difference between presence and absence, and physical properties of objects like their shapes and materials. He can sound out letters the same way a child does."
Amazing. What is even more surprising is that the structure of the avian brain is not like the mammalian brain at all. In mammals (and especially so in humans), the so-called lower regions of the brain have been enveloped by a thin sheet of cortical cells called the neo-cortex. This sheet is the base of human intelligence and is incredibly plastic. Further, it's assumed most of the control for many basic functions like breathing and hunger. The neocortex's pre-eminence is what allows people to consciously starve themselves to death. Arguably, it's the seat of free will (which I will blog about on a later date).
So how is it that birds, without a neocortex, can be so intelligent? Apparently, they have evolved an set of neurological clusters that are functionally equivalent to the mammal's neocortex, and this allow them to learn and predict complex phenomena. The equivalence is an important point in support of the belief that intelligence is independent of the substrate on which it is based; here, we mean specifically the types of supporting structures, but this independence is a founding principle of the dream of artificial intelligence (which is itself a bit of a misnomer). If there is more than one way that brains can create intelligent behavior, it is reasonable to wonder if there is more than one kind of substance from which to build those intelligent structures, e.g., transitors and other silicon parts.
It is this idea of independence that lies at the heart of Hawkins' "On Intelligence", in which he discusses his dream of eventually understanding the algorithm that runs on top of the neurological structures in the neocortex. Once we understand that algorithm, he dreams that humans will coexist with and cultivate a new species of intelligent machines that never get cranky, never have to sleep and can take care of mundanities like driving humans around, and crunching through data. Certainly a seductive and utopian future, quite unlike the uninterestingly, technophobic, distopian futures that Hollywood dreams up (at some point, I'll blog about popular culture's obsession with technophobia and its connection with the ancient fear of the unknown).
But can we reasonably expect that the engine of science, which has certainly made some astonishing advances in recent years, will eventually unravel the secret of intelligence? Occasionally, my less scientifically-minded friends have asked me to make my prediction on this topic (see previous reference to the fear-of-the-unknown). My response is, and will continue to be, that "intelligence" is, first of all, a completely ill-defined term as whenever we make machines do something surprisingly clever, critics just change the definition of intelligence. But excepting that slipperiness, I do not think we will realize Hawkins' dream of intelligent machines within my lifetime, and perhaps not within my children's either. What the human brain does is phenomenally complicated, and we are just now beginning to understand its most basic functions, let alone understand how they interact or even how they adapt over time. Combined with the complicated relationship between genetics and brain-structure (another interesting question: how does the genome store the algorithms that allow the brain to learn?), it seems like the quest of understanding human intelligence will keep many scientists employed for many many years. That all being said, I would love to be proved wrong.
Computer: tea; Earl Grey; hot.
Update 3 October 2012: In the news today is a new study at PNAS on precisely this topic, by Dugas-Ford, Rowell, and Ragsdale, "Cell-type homologies and the origins of the neocortex." The authors use a clever molecular marker approach to show that the cells that become the neocortex in mammals form different, but identifiable structures in birds and lizards, with all three neural structures performing similar neurological functions. That is, they found convergent evolution in the functional behavior of different neurological architectures in these three groups of species. What seems so exciting about this discovery is that having multiple solutions to the same basic problem should help us identify the underlying symmetries that form the basis for intelligent behavior.
posted February 3, 2005 02:17 AM in Obsession with birds | permalink | Comments (0)