Scientists Find Rats Aren't Smarter Than Mice, and That's Important 154
HughPickens.com writes: There has long been a clear hierarchy of intelligence in the psychology lab, with monkeys are at the top, then rats, and finally mice at the bottom, "cute and fluffy but not all that bright." For at least a hundred years, researchers have used rats in their psychology experiments, assuming that they were the smarter of the two lab rodents. Now, Rose Eveleth reports at The Atlantic that new research shows this might not be true, suggesting mice can perform decision-making tasks in the lab just as well as rats can. "Anything we could train a rat to do we could train a mouse to do as well," says Tony Zador. This finding is important because using mice in experiments instead of rats could open up all kinds of new research options. For one thing, scientists have been able to manipulate a mouse's genome in really useful ways, silencing certain genes to figure out what role they play. There are mouse models for everything from Alzheimer's to Parkinson's. Being able to put those mice through the paces of a psychology experiment could help researchers connect diseases with the behaviors they impact.
So where did this idea that rats are smarter than mice come from, anyway? Zador says it's a historical bias. "There was 100 years of practice in training rats. And basically when people tried to treat the mice in exactly the way they treated the rats, the rats seemed smarter," says Zador. In other words, "over the course of 100 years people had figured out how to train rats, and that mice aren't rats." You might think that mice and rats would be basically the same when it comes to these kinds of things, but Zador points out that mice and rats diverged somewhere between 12 and 24 million years ago. For comparison, humans and chimpanzees split somewhere between 5 and 7 million years ago. So it's no surprise that mice behave differently than rats, and that the difference impacts their training in the lab. "The mouse is uniquely placed at the interface between experimental access and behavioral complexity, making it an ideal model for the study of adaptive decision-making. Successful behavioral paradigms, however, rely on targeting designs to the idiosyncrasies of the mouse from the outset, rather than simply assuming that mice are little rats."
So where did this idea that rats are smarter than mice come from, anyway? Zador says it's a historical bias. "There was 100 years of practice in training rats. And basically when people tried to treat the mice in exactly the way they treated the rats, the rats seemed smarter," says Zador. In other words, "over the course of 100 years people had figured out how to train rats, and that mice aren't rats." You might think that mice and rats would be basically the same when it comes to these kinds of things, but Zador points out that mice and rats diverged somewhere between 12 and 24 million years ago. For comparison, humans and chimpanzees split somewhere between 5 and 7 million years ago. So it's no surprise that mice behave differently than rats, and that the difference impacts their training in the lab. "The mouse is uniquely placed at the interface between experimental access and behavioral complexity, making it an ideal model for the study of adaptive decision-making. Successful behavioral paradigms, however, rely on targeting designs to the idiosyncrasies of the mouse from the outset, rather than simply assuming that mice are little rats."
Intelligence isn't that important (Score:2)
Here's my argument: experiments that depend on measuring problem solving and it's interaction with the brain have never really been better from smarter creatures. What's most useful is behavioral consistency. Between members of the species, and with one individual's performance. The more predictable the baseline is, the more useful results you can extract from fewer tests against your control group.
Sure some thins are too complicated to hope to model so simplistically, like cultural learning, empathy,
Re:Intelligence isn't that important (Score:5, Funny)
experiments that depend on measuring problem solving and it's interaction with the brain have never really been better from smarter creatures
Citation needed. We gave our dog an intelligence test - put a treat under a paper cup and see if he's smart enough to move the cup and get the treat. Dog looked at me waiting for a signal, as soon as I said "OK" he knocked the cup over with his paw and grabbed the treat. Tried the test with our goldfish; he just flopped around on the floor.
Re:Intelligence isn't that important (Score:4, Funny)
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experiments that depend on measuring problem solving and it's interaction with the brain have never really been better from smarter creatures
Citation needed. We gave our dog an intelligence test - put a treat under a paper cup and see if he's smart enough to move the cup and get the treat. Dog looked at me waiting for a signal, as soon as I said "OK" he knocked the cup over with his paw and grabbed the treat. Tried the test with our goldfish; he just flopped around on the floor.
Try it with your octopus.
Re:Intelligence isn't that important (Score:4, Funny)
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humans and chimpanzees split somewhere (Score:2)
Whoa whoa whoa... We know that for sure now? With real quantifiable evidence, that I can see without a paywall? I musta slept through that part of the newcast... Somebody clue me in...
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Absolutely. You can tell because the chimps have a lot more body hair and don't make themselves miserable working 8+ hours a day at a job they hate.
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Whoa whoa whoa... We know that for sure now? With real quantifiable evidence, that I can see without a paywall? I musta slept through that part of the newcast... Somebody clue me in...
The chimps have already figured out how to get past the paywall.
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Yes, it is true and verifiable, no matter how much the chimps try and deny they are in any way related to humans.
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Pretty sure that humans and chimpanzees never split. We share a pretty recent common ancestor, but that's it.
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The point is that humans and chimps share a common ancestor. Neither species split off from the other.
This is pretty basis stuff - have to wonder how you missed this in your education.
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The point is that humans and chimps share a common ancestor. Neither species split off from the other.
well, they're separated and seeing other people.
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Far more recent than that. Has slashdot been overrun by Ken Hovind disciples?
I thought lawyers were the preferred replacement (Score:5, Funny)
Because there are some things rats just wont do.
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But then it's much harder to extrapolate the results to humans.
mod karma to 11 (Score:2)
very funny
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List of Animals by number of Neurons (Score:5, Interesting)
http://en.wikipedia.org/wiki/L... [wikipedia.org]
The rat has an estimated 200E6 Neurons and 4.48E11 synapses, and the mouse has 71E6 neurons and ~1E11 synapses.
There is at least some correlation between intelligence and the number of neurons. A cursory search found this: -- Fact or Fiction: When It Comes to Intelligence, Does Brain Size Matte? http://www.scientificamerican.... [scientificamerican.com]
It would be interesting to find more definitive articles that support or contrast this.
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It's more than just a matter of brain size, it's also the ratio of brain size to body size. A bigger body requires a bigger brain just to coordinate.
From your numbers, rats have about 3x as many neurons and 4x as many synapses as mice -- yet they're usually bigger than 3x or 4x times the size.
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Re:List of Animals by number of Neurons (Score:5, Informative)
Does body mass tend to scale linearly with brain mass?
No, it does not [wikipedia.org]. Humans have a brain:body ratio of about 1:40. Small ants are 1:7. The highest among mammals is a shrew at about 1:10. Small birds are about 1:14. Elephants are 1:560. Hippos are 1:2500.
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I don't have a brain! :(
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Brain and body size. Why? (Score:4, Interesting)
Yeah, I've never understood why that should be. It's not like a larger body has more degrees of freedom to coordinate, and I'm pretty sure the motor control nerves also serve as signal amplifiers, so you don't need more brain cells to drive a larger muscle. The only thing I can think of that might scale with size is the number of sensory nerves in the skin - which would suggest that the portion of the brain associated with processing the input should scale with the square of linear size (or alternately with the 2/3 power of mass).
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I'm pretty sure the motor control nerves also serve as signal amplifiers, so you don't need more brain cells to drive a larger muscle.
Not necessarily. I can easily imagine larger creatures needing finer motor control compared to their size (note that large humans are often described as "clumsy" and small humans as "graceful"). In a similar vein, I know one proposed theory about why humans are so much weaker than chimpanzees is because we dedicate way more brainpower to fine motor control (one source: http://www.smithsonianmag.com/... [smithsonianmag.com]).
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Given the number of small clumsy people and large graceful ones I've seen, I think that's more of a media meme and/or perceptual preconception than an actual trend...
That's an interesting article though, I hadn't thought of the fine muscle control aspect. I suppose neurons do pretty much fire in an all-or-nothing fashion, so it makes sense that if you want a more graduated response you need more nerves to be able to trigger smaller clusters of muscle fiber. A corollary to their theory about apes strength
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Interesting. But from what I can find (http://en.wikipedia.org/wiki/Motor_unit_recruitment#Rate_coding_of_muscle_force) that only allows for a 2- to 4-fold variation in force - not quite all-or-nothing, but severely limited.
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It's more than just a matter of brain size, it's also the ratio of brain size to body size. A bigger body requires a bigger brain just to coordinate.
Tell that to the Brontosa...er Apatosarus (poor creature. It went extinct twice!). Anyways, brain the size of a meatball - body the size of an articulated bus.
Divergence (Score:4, Insightful)
It'd be nice if my field's conclusions could be this broad...
Between this range and the fact that every reproduction is a "divergence", and so the baseline here seems to be divergence from one arbitrary cluster of characteristics given a latin name, and another arbitrary cluster of characteristics given a different latin name...
What does this even mean?
Yes, I know. I'll be shortly told I'm too dumb to understand, instead of an explanation. Fair enough, stipulated. Now go ahead and inform me of stuff.
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Fair enough, but as was already noted, speciation is not definitively determinable by ability to reproduce.
It's a pretty core problem with the term, scientifically, actually.
So, I was taking "divergence" in a broader sense, which also doesn't seem to work for the statement.
Still, I see nowhere that I insulted anyone. I addressed a particular sentence, which has multiple levels of lack of clarity. That's all.
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where you insulted people was -
"It'd be nice if my field's conclusions could be this broad..."
or in a more general form "it would be nice to be able to get away with [X] in my group, like how that group does" a sort of phrase which is usually used by people in one group to imply that the other group is inferior on account of doing X, in this case having more broad conclusions.
Divergence has a specific meaning in biology, just like it does in vector maths, you do not need to clarify in a discussion of vector
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Okay, but the category you cannot rewrite is also just as arbitrary, and pulled out of a hat.
You complying with them is, to all appearances, simply dogma and a mandate never to correct
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...mice and rats diverged somewhere between 12 and 24 million years ago.
What does this even mean?
Part of the problem is that we want clear and distinctive buckets (labels) to put things into: this a rat, this is a mouse, ... Evolution, slow, gradual changes over time, doesn't work that neatly. 12 to 24 million years ago there was some animal with some its descendants became today's rats and some other of its descendants became mice. That animal could interbreed with others of its kind. At some point its descendants branch that eventually became rats and its descendants branch that eventually mice
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So, you seem to be agreeing with me more than disagreeing. The categories are not clear and distinctive, which I went ahead and called "arbitrary", because that's what they are.
So back to the quoted sentence...
"...mice and rats diverged somewhere between 12 and 24 million years ago."
I still have no idea what actual information this is supposed to convey. Or is it more of a "rah rah, evolution!" reaction thing?
Pavlovian conditioning hasn't worked on me for a long time. Maybe that's my problem.
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I still have no idea what actual information this is supposed to convey. Or is it more of a "rah rah, evolution!" reaction thing?
You need something to compare it to; it's right in the article: "For comparison, humans and chimpanzees split somewhere between 5 and 7 million years ago"
So mice and rats diverged somewhere between 12 and 24 million years ago, while the range is 5 to 7M for humans and chimps. Humans and Chimps are very different and we'd certainly not try to treat chimpanzees as 'small humans' in a lab setting. Yet we tried to do so with mice, treating them as small rats.
Just a linear comparison would tell you that rats
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Yes... maybe my viewpoint of directed evolution makes me more attuned to certain aspects of such a statement.
I certainly agree that evolutionary processes are generally speaking most directly responsible for biological differentiation, but I'm unwilling to make the inference from that of "often, therefore always" and statements like the one quoted seem to border on pseudoscience in how broad, unspecific, and untestable they are. I personally think that science is best served by making scientific statements
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Yes... maybe my viewpoint of directed evolution makes me more attuned to certain aspects of such a statement.
That's... certainly a thing you can say.
Less charitably, I might say "Your preexisting faith in the supernatural hinders your ability to comprehend the natural."
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You might say that, and the only thing remaining would be to back it.
Let's start with me simply noting that I comprehend the natural quite well, eh, I'll go ahead and say better than you, and leaving you to show otherwise. That will require some actual content or an actual argument.
You see, I'm not one of those pushing the "religion versus science" false dichotomy who hope to damage religion and only end up damaging science. A frequent occurrence of people overextending their arguments with bias-driven ps
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I would like to see *some* evidence that "directed evolution" occurs without human intervention. Mind you, we don't usually try to create new species. At one time we couldn't, these days we occasionally do. (For an exception, Corn [Maize] is a different species from Teotsine, but I'm not sure you could say people created it rather than merely preserved it.)
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So, you agree in principle with directed evolution, in that you directly say man is one cause of it?
I imagine there's one, and only one, source of design you categorically reject. I wonder what that would be...
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Do you imagine that you provided evidence?
Admittedly, once evidence was provided, I would attempt to judge it's quality before accepting it, but I didn't see that you even offered any.
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Neat Bare Assertion fallacy.
I trust your evidence for this will be forthcoming. Bonus points for other possible design influences, such as extraterrestrial life, and by what criteria you are dismissing one with a certainty you can't apply to the other.
Oh, who am I kidding. You're devoid of honest thought. Evolution can go ahead and eliminate you.
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Well don't overstate my position. I mean, I do heed Darwin's concise summary of his Origin of the Species and the social turmoil implications of it, in 1859:
"When you see your likeness, you are pleased. But when you see your images which came into being before you, and which neither die nor become manifest, how much you will have to bear!"
Oh wait.
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I don't understand. Both directed evolution and ID are plausible positions. After you claim they are not, even when you invoke the conclusions of lawyers whose scientific credentials are assured by wearing a black robe and sitting on an impressive raised platform, it will remain exactly as plausible as it in fact is.
Complexity is evidence. You'll claim it is not, that will be your interpretation of the evidence and not in any way affect the reality it is evidence. That such complexity could -also- be ex
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Directed evolution can't be ruled out. We can't easily tell a random process from a process some entity wanted to look random. There's no evidence for it, but it fits nicely with some people's religious beliefs. Intelligent Design makes sense only as a variation on directed evolution. (I do know one scientist who does believe personally in directed evolution, for religious reasons.)
So, most of us don't have a problem with you sitting in your room and believing in directed evolution. Some of us have
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Of course, I don't care in the least what you or the entirety of Slashdot have "a problem with", as is appropriate, because it simply could not in any way factually matter.
That said, though, again, this is an issue of interpretation. Insofar as a given IC structure does not currently have, within the scope of science, a d
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This has nothing to do with what Occam's Razor says.
It continues to astonish me how consistently erroneous the understanding of this is on Slashdot, and how suddenly this mass-misperception of this statement of my fellow theist Occam has propagated.
I can only conjecture this is due to the mass-misdirection efforts of Dawkins et al.
Occam's Razor says nothing about probability. Occam's Razor says nothing about the validity of inferences from given observable phenomena. Occam's Razor says, and -only- says, t
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"I exist, so I must exist for a reason!"
"If you didn't exist, didn't have the brain power to think, etc, you wouldn't be in a position to ask the question. Ergo, all you're proving is you're conscious."
"Ah, but consciousness is proof!"
"Proof that you have consciousness. Just like any other being that had or will have consciousness."
Not sure if you are unaware, equivocating, or simply intellectually dishonest, but none of t
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Wow, what an amazing limitation on your thought processes. Applying that must keep you at approximately the intellectual range of someone severely mentally handicapped. Fortunately, it's complete nonsense, according to science and... well, everything. A chain of inference from
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It's not so much the generation time, as that rodents generally have a faster mutation rate than primates. Generation time is also significant, though as it allows less-viable variations to be more quickly weeded out.
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I think we've all been there.
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It's not an arbitrary point of "divergence", it's a retrospective one. You can't know that these two individuals who are siblings are members of a different species until considerably later you observe that their descendants can no longer interbreed (or never choose to do so). Picking those two individuals as the fork isn't arbitrary, but it's also impossible to do at the time, you can only do it by looking at their descendants.
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I think evolutionarily speaking "divergence" means the point at which members of the respective subgroups (mostly) stopped interbreeding, and it is a very fuzzy line. I mean dogs and wolves diverged many millenia ago, but they still *can* interbreed, they just mostly don't. Foxes on the other hand diverged far longer ago than that, and are no longer capable of interbreeding.
Measuring the distance in years seems somewhat ridiculous though, generations would be far more telling. I can think of only two reas
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Also the fossil record shows elapsed time but not number of generations.
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Good point.
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The arbitrariness of species is one of the realizations that lead to Darwin's book. It forms a key part of his argument. Divergence time means "time to last common ancestor". If we take these arbitrary groupings, and say these are mice, and these are rats, then we can take a rat and a mouse and use genetic tests to guess how long it has been since they shared an ancestor.
What we'll probably find, even though our initial grouping was arbitrary, that for the most part a given mouse and a given rat's common
Pinky and the Brain (Score:2)
I always new that show was real.
sure mice are smart (Score:2)
Maybe not intelligence but... (Score:1)
As someone who's had both rats and mice as pets, rats are much more comfortable being handled and are somewhat affectionate. Mice tend to be jumpy and skittish and don't seem to bond to people so much. Lab mice are very retarded and slow (for very good reasons) compared to wild caught mice or their offspring.
Mice might be as smart, but rats are much more fun to work with.
Clearly.. (Score:2)
That seems odd (Score:3)
It doesn't seem like it makes much sense to believe that rats and mice are different enough for one species to be measurably smarter than the other, but not to also believe that they're different enough to have different behavior patterns and responses to various stimuli.
heh. Rats, you've been outsourced! (Score:2)
we can pay a mouse 1/3 fewer pellets, pack them into 1/5 the space, and still be just as abusive!
Rats vs Snakes (Score:3, Interesting)
The rats on the other hand immediately detected the snake as a threat. They hid behind things, keeping themselves obscured from direct line of sight of the snakes.
I have also had both rats and mice as pets. The rat I could teach to come to me when I whistled, the mice not so much... though maybe that was because I never tried to really train the mice. But I'm not convinced.
So where do the scientists fit in? (Score:2)
"There has long been a clear hierarchy of intelligence in the psychology lab, with monkeys are at the top, then rats, and finally mice at the bottom, "cute and fluffy but not all that bright."
So where do the scientists fit in? Somewhere in the middle? Just above rats? Hmm...
Smarter or not, I choose rats. (Score:2)
Having worked in labs with both mice and rats, I'll take a nice Sprague-Dawley any day. They're like little dogs: they hang out, they like to be petted, they're clean and smell nice.
On the other hand, as soon as you lift the lid off the mouse cage, one of those little buggers levitates three feet in the air and rockets off in a random direction, probably sinking their teeth into someone's earlobe. No thanks.
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Sure you're not confusing them with squirrels?
HHG (Score:2)
Slartibartfast: [talking about the Earth] Best laid plans of mice.
Arthur: And men.
Slartibartfast: What?
Arthur: Best laid plans of mice and men.
Slartibartfast: Oh. No, I don't think men had much to do with it.
Rats just figured ... (Score:2)
"Hey you humans. There's a mouse over there. He's really smart. Why don't you fuck with him for a change?" Its the same logic I use when the wife asks me to do something around the house. Mess up a couple of times and she stops asking.
Clear hierarchy? (Score:2)
I don't think any proper scientists has thought in terms of a hierarchy of intelligence since we discovered that quantifying intelligence was harder than we thought (about a century ago).
But I could certainly see journalists thinking in those terms.
Blow that Sax, Socrates! (Score:2)
Song (Score:2)
OK, who thought of this song first upon reading the summary?
http://en.wikipedia.org/wiki/A... [wikipedia.org]
(I have no idea which of the versions listed I've heard.. maybe the Muppet show.. but it's one of those songs where I definitely haven't seen the _original_, or at least not in its entirety, but still know the song.)
YEAH it's important!! (Score:2)
It totally screws up the Secret of Nymh. :_(
Buuuut... They were genetically enhanced rats, so it still works.
It's ok everybody CRISIS AVERTED!!
How do you identify a New Yorker? (Score:1)
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I was once in a position to observe a larger and more significant population of mice. While a population of 10 wasn't large enough to observe the appearance of a "prodigy", a population of roughly 100 was.
Re:Correct Hierarchy (Score:4, Insightful)
You forgot
0. Whiny depressed robot with a brain the size of a planet.
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-3. Guide Mark II
-2. Earth (a planet (or two))
-1. Marvin (robot with a brain the size of a planet.)
0. Deep Thought
1. Mice
2. Dolphins
3. Humans
4. God, (before the puff of logic.)
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If you RTFA, they are getting their consent:
If they didn't want to participate in the testing, they were free to do so by not sticking their noses in the start port.
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If they didn't want to participate in the testing, they were free to do so by not sticking their noses in the start port.
Not strictly true. See, the trick is to just not put a water bottle into the cage and make water the reward.
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They still recieved water without doing the test, just not as much. By your logic, if someon offers pizza to help them move, they're forcing me to help them.
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What did one lab rat say to the other? I've got my scientist so well trained that every time I push the buzzer, he brings me a snack
I'm pretty sure that any parents with young children know how this works. :-)
Re: So don't use mice or rats for experiments. (Score:4, Interesting)
What did one lab rat say to the other?
I've got my scientist so well trained that every time I push the buzzer, he brings me a snack
There is actually some truth to this. I have had both rats and mice as pets. They may be equally smart, but they interact with humans very differently. A rat that is handled regularly can become very tame. My rat would curl in my lap to sleep. If hand raised rat escapes from its cage, it will seek out humans, and beg for both food and companionship. I have never seen that behavior in mice. They don't like to be picked up or handled, and they don't bond with humans.
It is similar to the difference between dogs and cats. They are about average in intelligence, but dogs are far easier to train, because they care about pleasing humans, and cats don't.
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The paper actually doesn't even make the claim that rats and mice are equivalently intelligent, just that they were able to train mice to do the same things that they could train rats to do.
Their data show: 1) it took twice as long for the mice to learn as it did for the rats, 2) mice benefited from an additional basic learning stage that the rats did fine without, and 3) mice were more variable in their learning speed, while rats were more consistent.
However, they were working with tasks that had been desi
Re: So don't use mice or rats for experiments. (Score:5, Funny)
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If you're posting here, dare I hope that Slashdot comments will get better in quality?
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No, there's a movie about it: the smart rats all escaped to some farm. They're fine.
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Are you smart enough to see the difference between intentionally and knowingly harming things and unknowingly doing so when going about your life? Are you consistent enough to see that we actually acknowledge this difference in our own legal system?
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do you lead a pesticide-free existence? .....
said by the biggest pesticide on earth.
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s/pesticide/pest
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Interesting. I've had the opposite result with mice. I can get the young ones easy, but the old wily ones I got to trick some how. The last infestation I had to deal with was 11 mice. The very last mouse I killed was this big fat misshapen guy who ran slowly and in a straight line. No dodging, no attempt to hide. I literally dropped a trap right in front of him and he walked into it.
My interpretation is that that mouse family was taking care of their disabled relative.
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