Crawling Into Consciousness

By Sean Carroll | March 23, 2011 10:22 am

We’re not very good at defining what “consciousness” is, although we think we know it when we see it. One promising avenue of attack on the problem is to consider how consciousness may have developed over the course of the evolution of life. There’s a great blog post about this by Malcolm MacIver over on our sibling blog Science Not Fiction. He is thinking about an obviously-important event in the history of life — the moment when aquatic organisms first flapped up onto land and starting breathing air, if we may greatly simplify a complicated process — and asking about its consequences for consciousness.

The idea is one of those deceptively simple ones that makes you wonder why you didn’t think of it all along. The point is: attenuation lengths. In water, you just can’t see very far; your vision becomes blurry after a matter of meters. Consequently, you don’t have much time — maybe seconds — to react to the world around you, whether what you see is prey, a danger, or a potential love interest. So the evolutionary pressure is to “make up your mind” extremely quickly, essentially right away.

Now imagine you crawl up into the air. Suddenly, you can see for kilometers! Now a different mode of action becomes useful: thinking about hypothetical alternatives. Under water, too much Hamlet-like equivocation would have made you someone’s dinner before long; now, you can ask yourself whether it would be better to duck under a rock, scurry up a tree, or finally take a stand against that big bully.

The ability to contemplate competing alternatives before making a decision is a crucial part of what we call consciousness. It’s related to another idea I believe I first got from Steven Pinker’s The Language Instinct, although I don’t remember the precise passage: the claim that what really separates the conscious from the non-conscious is the ability to use grammar. In particular, the subjunctive mood, in which we talk about hypothetical futures. (“If I were to go and bring you back some tasty fish, would you let me live?”) Lots of animals can communicate using something like “language,” but the ability to make agreements based on contrary-to-fact scenarios is what separates the shouters from the negotiators. And of course, the ability to contemplate hypothetical scenarios is an important prior step to being able to communicate about them.

Be sure to read the comments, where man good questions are asked (“What about octopuses?” “Aren’t there senses other than vision?”) and also answered. Malcolm also provocatively tries to imagine what it would mean if we vastly improved our sensory capabilities, which of course technology is doing for us all the time. What’s next after consciousness?

  • Dan

    I thought I thought I was, therefore I might have been?

  • Mike

    Not to belabor past discussions, but if:

    1. Consciousness is a wholly evolutionary and physical process, and

    2. Moral conclusions are wholly the result of consciousness, then

    3. Moral conclusions are a wholly physical process, that are

    4. Susceptible, at least in principle, to scientific analysis and explanation.

    Not exactly “ought from is”, but a necessary first step, no? And, at least to me, it doesn’t seem like such a huge philosophical reach to someday be able to scientifically determine that certain moral conclusions more closely conform to natural laws, and thus, are more correct . . .

  • Guilherme Caruso

    So, based on that premisse – that the ability to see farther relates to consciousness – one could wonder if human consciousness arose from looking at the stars…

  • Carlos

    @Mike: (I’m not sure you were joking or not, so forgive me if you were joking. I just want to try and avoid a misinterpretation) Your argument is actually correct. But it doesn’t say what your smiley seems to imply. Your argument simply says that morality can be analyzed. And that’s true. What the argument doesn’t say anything about is whether holding one moral notion or another is “right”.

    “Rightness”, as Carroll tirelessly points out, is an “ought” notion. Susceptibility to analysis is an “is” notion.

  • Mike

    4. @ Carlos:

    The smiley was gone in the last posted version. Sorry for the confusion.

    I agree that my chain of logic doesn’t lead directly to answering whether one moral notion is more right than another. That’s what the final, less than rigorous, paragraph was trying to get at.

    I’ve read through the comments to the link Sean posted and part of the discussion deals with the issue of moral conclusions arising from consciousness — and more interestingly, the possibility/probability of better moral conclusions and behaviors arsing from augmented and expanded consciousness. This wouldn’t be possible, would it, unless moral “rightness” was the outcome of wholly physically processes? At least that’s my read on the author’s theory.

    I think your last sentence assumes the conclusion you want to reach.

    I respectfully disagree.

  • Rohan


    “2. Moral conclusions are wholly the result of consciousness”

    Are they? I thought the thing was that sometimes moral judgements were gut reactions possibly dependent on the environment and not necessarily deeply thought-out ideas. I guess it may depend on the definition of consciousness, which should probably come before #1.

  • martin smith

    There must be the possibility that mental speed adjusts to (inverse) attentuation lengths: Fish simply live with a proportionately faster mental clock and there is no qualitative difference between subsea and surface thought processes.

  • Mike

    6. @ Rohan,

    In my view “consciousness” encompasses “gut reactions possibly dependent on the environment and not necessarily deeply thought-out ideas”, because it consists of everything our brains (think) we know, however arising and from whatever source.

  • David George

    #2, 5, 8 Mike — Exactly right.

    I believe there is a “right” to be found in evolution, and that is in the sense of harmony, which we may not “consciously” ponder but which we naturally sense. (And I believe that harmony is a physically real phenomenon, as is chaos, in physically real systems.)

  • Mike

    9 @ David George,

    That’s an interesting view. I’m not sure whether “harmony” is the proper concept, but absent the “experiment” of enhancing human consciousness on a large scale and seeing what ensues over time, or running an increasing number of arbitrarily accurate simulations of the human brain in action and developing some kind of measure of “moral” outcomes, both of which, it’s safe to assume, are some time off, I don’t think we’ll ever know. And, even then, if patterns emerge that lend credence to the view that “ought” can be derived from “is”, it won’t “prove” that it’s correct. It will only be some evidence that our theories are probably pointed in the right direction.

  • Sphere Coupler

    We are already involved in ” What’s next after consciousness?”.

    The answer is meta-consciousness, and the form it has taken is the Internet and the Blogosphere is a component of the whole.
    Religious gathering is also a form of meta-consciousness, though the prescribed subject matter is narrow.
    I kinda hope we are still far away from this completed concept because I would rather function as an individual…but then their is twitter and face-book, where almost all is laid out to see.

    And then their is the cell phone, I see a lot of students and you could almost swear the phone is glued to their heads or hands(texting).
    Communication has evolved the ability to couple modes of information transfer and accumulation,
    Now back in the day, this was accomplished through the church or sale barns/markets or many other isolated events such as group hunting etc.
    Today the processing is faster,compounded and some times more efficient.

    It’s safe to say that the critical mass of humanity for Moore’s law has been reached and continues.In other words the greater the mass of humanity=the greater advancement in technologies.
    Just as 911 allowed us to receive a glimpse of what our world was like with fewer people burning carbon, no fly zone and people hunkered down in their domiciles (less traffic). We had for a brief three days bluer skies and fresher air and this can be accomplished again with determination for a cleaner, more local, and responsible generating sources.

    Just as 911 allowed us to experience a piece of the past…
    Think what it would be like if all those new forms of communication were inactive for a period of one month.
    *I picture zombie-like people roaming the streets looking for a long defunct pay phone booth.*


    People would be forced to only communicate in person or perhaps a land-line.

    Maybe the next step in evolution is directed communication between individuals without the need of an external apparatus.

    Now, since it seems winter has returned, I’ll snuggle up to a hot *cup o Joe* and follow the links provided, probably to find that much of what I said has already been covered.

  • David George

    #10 Mike,

    I use the word “harmony” because it has both physical and social applications. The root of the word has the sense of “fitting together”. If existing systems create new systems by sensing – and reacting to – relative harmonic or chaotic internal and external conditions, then systems grow according to harmonic signals. Whether this conceptual view can be quantified I don’t know. But I don’t believe knowledge is simple quantification and prediction. It is also interpretation, and the understanding is in the interpretation, not the quantification or prediction.

    How to approach the question of “ought”, as being derived from “is”, may be a little too advanced for me. If we see what “is”, and we see that the universe operates by a harmonic principle, then it seems more or less self-evident that we should try to operate by that same principle. That does not mean we can predict harmony, nor does it mean that harmony is evident in every situation. The more complex systems become, the more complex their internal and external harmonies become, and the more possibilities for chaos. Now this is getting too complex for me. A simple rule would be “Seek Harmony” — it’s kind of a variant of the Golden Rule.

    Say, for example, we naturally maintain our balance (according to the workings of our eyes, inner ear, etc.) relative to the ground. Then at some point we find ourselves continually losing our balance and falling over. Is it a moral question, whether we “ought” to see a doctor? Broadening that to social organizations, if they naturally maintain some degree of social “balance” — say, full employment, or constant money value — then if they find themselves out of “balance”, is it a moral question whether they “ought” to do something? If they don’t, then they will endure chaos, and who knows what will be born? (If some sociopathic system, say “democratic capitalism”, operates by artificially induced chaos, how does it grow? Maybe like a cancer?)

  • MT-LA

    @David George: I get what you’re trying to say with the harmony thing. I don’t agree, but I get it.
    But this is the second post in as many articles that you’ve mentioned this term “democratic capitalism”, and qualified it as sociopathic. You seem to be throwing this out as bait, so I’ll bite: what is democratic capitalism, and please tell me why I should fear it/hate it/have it surgically removed.

  • spyder

    Reading both posts and comment threads, i still am feeling that the question is not fully resolved. Whales, dolphins, and other ocean life, not only echolocate, but have quite excellent hearing, vastly better than humans. We developed technology to converse orally/auditorily over distances of several meters, and over kilometers with instruments. Whales spend most of their lives communicating to one another over incredible vast distances without technological help. Whales also have quite excellent eye sight, as do dolphins. Paleontologists, while holding the view that these species evolved back into the water after mammals came ashore, still can’t quite identify the various connections to prove the case. Perhaps reptiles would be a better measure of this new theoretical kant. Snakes sense movement with their belly nerves, crocodiles with sharper senses of ripples in the water and keen vision. So many species, so many paths of evolution.

  • sievemaria lucianus


    Observations and communications through nature and especially in the arts and sciences – can have a almost mystical depth – detached vision or unprejudiced vision where objects loose their names but receive their existence and value exclusively from a certain accord of the soul, the eye and hand of someone born to perceive them.

  • David George

    #13 MT-LA —

    “Democratic capitalism” is not my term; the first time I heard it was from George W. Bush, the former presider-in-chief, who stressed (following a recent “economic pratfall”, you may remember it) that financial reform is fine as long as it does not threaten “democratic capitalism”. So I guess that would be the system where money is loaned into existence out of thin air and provided to the sociopaths, who then waste it and come back for more, while passing the bill onto the people who generally aren’t sociopaths — the poor. There is more to it than that, of course. “Democracy” is a convenient cover story for government by the sociopaths, who own the government. I must say they have pretty well figured out how to fool enough people enough of the time to thrive over a few thousand years of generally continuous warfare and chaos. I’m not sure whether fear or hatred will help you, and I don’t think there is much possibility of surgical removal at this point, since the system has reached the limit of its host — Earth — and is now pretty much terminal. As for therapy, this too shall pass, as the man says. And since living creatures always want to grow, new systems will undoubtedly be born.

  • Low Math, Meekly Interacting

    I’m not sure vastly increasing our sensory capabilities does much for consciousness, because we’re not able to vastly increase our mental processing capability. The result appears to be sensory overload and, if anything, attenuated consciousness. Our information collecting and transmitting technologies are following Moore’s law, but our brains most certainly aren’t. It’s like asking what will happen to the ability of fish to absorb oxygen from water if we deliver it directly to the gills with a garden hose turned on at full blast.

  • Cody

    I’d propose that consciousness is nothing more than the ability to ‘observe’ computation, as well as interfere with it–one more sensory input to the brain. A general simulator, a memory, some inputs, some outputs… probably simpler than we appear. Does anyone proposed this elsewhere?

  • Nex

    This makes no sense whatsoever.

    First of all you will actually see farther in clean water then in the jungle or forest.

    Second, there is no evidence to support the assertion that increased depth of vision gives land animals more time to avoid predators.

    Third, if it was about depth of vision birds would be most self-conscious by far.

    Fourth, such speculations are completely worthless – there is no way to clearly define what is meant by consciousness and therefore no way to test the hypotheses.

    What we cannot speak about we must pass over in silence.

  • James Moening

    Many good questions.

  • Jim Cross

    Agree this makes no sense.

    For one thing, it seems to conflate consciousness and vision and forgets that vision is just one of the senses. This is a common problem since humans are such visually oriented creatures that most of our terms for consciousness seem to have a visual element – “see a solution”, “look at options”, “envision alternatives”, etc. Yet there is no reason that consciousness and vision are necessarily related. Dolphins, whales, and bats are much more auditory creatures and it is highly likely that at least the first two have consciousness unless we are restricting the word “consciousness” to apply only to humans.

    If we narrow consciousness to humans, we need to look to language and its evolution. That sense of “I” is primarily a language construct that has embedded itself in neurology.

  • AnotherSean

    Consciousness- thinking about it makes me feel like a fish out of water!

  • Blunt Instrument

    I agree with Jim and others. It is a very “human-centered” view of consciousness because it it specific to our primary sense, vision. It would be ridiculous to think that aquatic predators would not have the ability to “sense” prey at reasonably large distances. Otherwise, they would starve for lack of food.

  • Cody

    Nex, those are all good points, but I disagree that we must (or should) “pass over in silence” just because we don’t know much about it or have no agreed formal definitions. Contrarily it is rough discussions which often lead to more serious investigation. We’ll probably have to propose a lot of definitions of consciousness, and refine/redefine them over time as our understanding develops—but it won’t develop if we don’t discuss it. Also, birds are among the more intelligent creatures, probably the class of animals with the most intelligent species (besides mammalia of course).

    Jim, you make good points, though on a grainier scale, in general we see brains increasing in complexity from fish to amphibians to reptiles and then to mammals and birds, right? Your examples of consciousness in primarily auditory animals are still all mammals, so their higher cognitive functions ultimately originated in land-based ancestors. (Figure once nature has a certain sort of brain template, many specific environmental factors (other than sight) would all shape the brain into something much more sophisticated.)

    An example I like to use of very primitive conscious control (arguably), is the way dogs (while panting to cool down) will hold their breath to investigate a sound.

    Also, we shouldn’t treat this hypothesis as claiming a rigid perfectly correlated causal relationship, but more providing one (of many) environmental selection pressure.

    In college I read once that it had been hypothesized that the evolution of vision was responsible for the Cambrian explosion… looking it up suggests it remains a hypothesis, but is widely rejected. They don’t seem to mention that the evolution of eyes must have driven (indeed, invented) sexual selection pressures, at least as far as form versus mate selection is concerned. (Without eyes there’d be no pressures to evolve camouflage, imitation camouflage, beautiful plumage, etc..)

  • Ryan

    I think the productive thing here is first to get a reasonable, agreed upon definition of consciousness. Setting aside for a moment the problem of qualia, what consciousness and self entails is actually remarkably well agreed upon.

    As a first principle, we must recognize that our subjective experience is wholly created by the brain – we are not privy to the direct sensory inputs. The world you experience is a very, very effective simulation, constructed from multiple streams of information. It is important to note that “effective” is meant in an evolutionary context, not that the simulation necessarily corresponds well to reality. (This actually is helpful to remember when thinking about information theory generally, and the holographic principle specifically – A classical computer could construct a simulation with as many spatial dimensions as needed, and as long as it made good predictions, the underlying structure truth is irrelevant to evolutionary success.)

    Consciousness is a feature that comes out of detailed world models that can make predictions. Obviously to think about the future requires a great deal of inductive reasoning, and any model sufficient for making complex plans will necessarily include an “avatar” in the simulation space. This “self symbol” is of such prime importance among other ideas that it is virtually constantly updated, with the temporarily associated symbols and structures forming the basis of your current subjective experience. This intimate relationship with abstract, infinitely extensible symbols is why people like V.S. Ramachandran tend to believe that the development of language is crucial for the function of higher consciousness.

    So, increased vision is certainly not a requisite for consciousness (just ask the octopodes), but I think it’s not unreasonable to say that general resolution and processing of sensory data is a path to creating sufficiently complex internal models to support planning. Getting to land incentivizes a higher degree of visual acuity and therefore probably sped the evolution of (human-level) consciousness.

  • Jonathan Lubin

    Sean, be careful. As I understand it, contrary-to-fact conditionals are omnipresent in the Indo-European languages, but people speaking non-IE have great trouble with them. I’ll be happy to be corrected by a linguist familiar with non-IEs.

  • John R Ramsden

    On a related note, hopefully not off topic, I’m sure dreams originated in a primitive form of visual memory, or “action replay mechanism”, to remind early land-venturing ampihibians of the route to retrace their steps back to water.

    Like many adaptions, doubtless dreams have more uses these days, such as organising and filtering memories. But that’s no contradication with them having some other initial purpose.

    If you think about it, when are dreams by far the most prevalent and vivid? Answer – When one has had a skinful, and awakes parched – Ultimately, like hiccups (a reflex originally to draw water across our gills!), it all goes back to water. 😉

  • Alan

    What’s next for consciousness?

    Nonphysical consciousness/awareness, intelligence without the so-called physical.
    There is evidence for it but it is also being seriously investigated as an explanation for near-death experiences using cardiac arrest as a study (physiological, chemical effects can be closely monitored) by an international team of doctors and scientists. Some results of this research may be published either this year or 2012.

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  • self-assembled

    Dolphins and whales evolved their quite capable long-term consciousnesses in the water. Their nearest land-dwelling relatives and early ancestors lacked this capacity.

  • Steve Turrentine

    @26 J. Lubin: There are a great no. of non-IE languages out there but the one I’m most familiar with is Japanese & I can say w/o equivocation that they CAN express contrary-to-fact conditionals in the language, altho their grammatical form is quite different from IE langs. due to their different origins. Altho I don’t know Korean I know people that do & they tell me that it can be translated word for word into Japanese & vice versa so presumably they have the same kinds of conditionals as well. I’m sure there are many other non-IE langs. that have them, too.

  • John R Ramsden

    @self-assembled [#30] Oh yes, I’d forgotten about cetacians. As brain scans have revealed, these species don’t dream (so I’ve read).

    The conventional reason is that with little constraint on brain size there is no need for dreams to shuffle their memories into more limited space, and doubtless that is true today.

    But arguably it is also indirect evidence for my water theory (#27), in that they are never short of water and thus presumably never thirsty. So they never have a need for an ancestral reflex to mentally remind them of the way back to water and then wake them with the vision fresh in their mind.

  • Mike

    28 @ Alan,

    “What’s next for consciousness? Nonphysical consciousness/awareness, intelligence without the so-called physical. There is evidence for it . . .”

    I really doubt this. What exactly is the “evidence” for non-physical consciousness. Sounds impossible.

  • AnotherSean

    Mike: I can’t imagine a non-physical manifestation of consciousness, either. But my guess is that to the extent we make progress in understanding it, the particular physical substrate will become less important. If so, we might end up talking about consciousness in terms of organizational structure and information flow. Now all of these things are embodidied in the physcial, but the underlying principles.. its hard to know what to say about those.

  • Douglas Watts

    This is totally and ridiculously uninformed woo. Visibility underwater in a coral reef is far better than ‘above ground’ in the thick mangrove swamp next to it. And visibility by sound is 100X better underwater. Even that aside, the premise still makes no #$%^ sense. How does ‘being able to see more stuff’ lead inexorably to ‘consciousness’ ? Humans actually have really crappy vision and senses. Our hearing is bad; our sense of smell is non-existent; no sonar; no infrared like snakes; no UV vision like bees; can’t swivel our heads like owls; eyes on the front of our heads; no lateral lines like fish. We’re practically blind, deaf and non-olfactory compared to most other vertebrates. Our nearest ancestors, early primates, lived in thick forest growth, in trees, which are terribly vision limited. All for good reason: concealment from predators, not vision, was our most important ‘earliest’ adaptation as semi-bipeds.

  • Alan

    33+34. Mike and AnotherSean

    Over 10 years ago I got to know a remarkable group of professional scientists who investigated a group of four people, in whose presence some quite stunning phenomena took place. They were investigated by many scientists at settings in the UK, Europe and the US (by some scientists from NASA). This was the conclusion of three of the (very senior) investigators who studied these phenomena over three years:

    “This report is the outcome of a three-year investigation of a Group claiming to receive both messages and materialised or physical objects from a number of collaborative spirit communicators. It has been conducted principally by three senior members of the Society for Psychical Research. In the course of over 20 sittings the investigators were unable to detect any direct indication of fraud or deception, and encountered evidence favouring the hypothesis of intelligent forces, whether originating in the human psyche or from discarnate sources, able to influence material objects and to convey associated meaningful messages, both visual and aural.”

    The Scole Report (1999) is 300 pages long and well worth full reading. The above is the abstract. In particular it is worth reading about the quite stunning light phenomena observed by many.

    I would advise to concentrate on the extensive phenomena witnessed not the “setting” in which these phenomena were seen, which rather tends to set a default point of view.

    This kind of evidence for nonphysical consciousness or awareness I would also say opens up the door for many possibilities, perhaps even considerations to do with religion.

    This group, The Human Consciousness Project, are also looking at the possibility of nonphysical consciousness/awareness through near-death experiences. Results not in yet – late 2011 or 2012 I think.

    If you click on Collaborators and Advisors you will see that they are quite senior.

  • Alan


    You say “we might end up talking about consciousness in terms of organizational structure and information flow. Now all of these things are embodied in the physical.”

    This is the accepted default working position. But with these new phenomena, it seems that “organizational structure and information flow” may be embodied somehow in space itself. And surely this is not surprising considering space is the ground of matter, or the fundamental ground of everything – so perhaps non-physical consciousness/awareness can scope around in this stuff? Seems reasonable.
    It says something about the properties of “space” as well.

  • John R Ramsden

    In relation to Douglas Watts’s theme [#35], my only slight reservation at first was that a lungfish flapping about out of water, with its vision adapted for underwater, would probably have had to contend with even more blurred vision and glare than its normal view, even if somewhat murky, underwater.

    And it’s not as if the land environment was benign, with three foot scorpions prowling around, and giant dragonflies darting overhead.

    But I guess it wouldn’t have taken long for early amphibians to evolve eyes capable of focussing both in and out of water, after which the supposed consciousness expansion could get underway. So I don’t think this is anything like a fatal flaw in the theory.

  • Douglas Watts

    John R. Ramsden — “a lungfish flapping about out of water, with its vision adapted for underwater, would probably have had to contend with even more blurred vision and glare than its normal view, even if somewhat murky, underwater.”

    Based on today’s lungfish, vision is a decidedly small part of their sensoral repertoire. I’m questioning the entire premise of why a transformation from a wholly aquatic lifestyle to a terrestrial lifestyle changes much of anything, except for breathing air through the atmosphere, obviously, and growing feet from fins. Eels can breathe through their gills and through their skin, which allows them to survive for hours and days out of water as long as they are moist. This is a very very old adaptation (50-100 my). And eels get really big and long-lived (Check James Prosek’s recent book about New Zealand longfin eels that are almost as big as people). So on this basis should we consider eels among the most ‘conscious’ of all vertebrates?

    Whales started as fish, evolved with us from the earliest known mammals, lived on land for tens of millions of years, and then decided to go back to a completely aquatic life 30 million years ago. They traded fins for feet and then feet for fins. Humans and primates never did that. Once we came out of the water we stayed out. So shouldn’t whales be more ‘conscious’ than us? They’ve done everything, twice !

    I’m just confused about the terms and references used here.

  • Lila Sovietskaya

    My article 16 at responds partially to this.

    I had no consciousness when I wrote it and i stiil do not consciousness. I am deluding myself that I have a consciousness or am I deluding myself that I do not have one?

  • Ted Erikson

    I have applied for a grant on “panpsychism” using my background in thermodynamics and swimming. Panpsychism is an ancient philosophy that implies ALL things are aware and exhibit a hierarchy of “consciousness”.
    Is a bit murky scientific subject, but I “feel” that light can not be perceived without the surface of mass to reflect from, refract with, or diffract, i.e. “needs” mass. Mass “needs” time and bigger is better, hence growth and evolution…T hey are synergetic.
    I have posted the application on a google knol, and also on my website blog. Any input welcomed..

  • rick

    it would seem logical to explore the idea that consciousness is really external and hyper dimensional. it exists prior to being incarnated human or Klingon. your heart has a brain also.

  • Frank Burns

    So much for the idea that dolphins and whales are conscious — they live in the water and therefore have blurry vision. Oh well.


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Cosmic Variance

Random samplings from a universe of ideas.

About Sean Carroll

Sean Carroll is a Senior Research Associate in the Department of Physics at the California Institute of Technology. His research interests include theoretical aspects of cosmology, field theory, and gravitation. His most recent book is The Particle at the End of the Universe, about the Large Hadron Collider and the search for the Higgs boson. Here are some of his favorite blog posts, home page, and email: carroll [at] .


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