Inverts & Pain - The Ultimate Thread

[Cirith Ungol]

There are cases of humans cutting off their limbs when the alternative is death, say when pinned by a rock or something. Just saying :}

Yes there are. But the case you are mentioning is not the same as a tarantula losing a leg. When pinned by a rock you have the choice between dying of starvation or bleeding to death or other. Or you can (if you can manage to actually cut the leg off) chose to live with a false leg... if you make it.

The T still has 7 legs left and does manage just as well with one leg temporarily missing.

 

[SpiderDork]

Pain - "An unpleasant sensation occurring in varying degrees of severity as a consequence of injury, disease, or emotional disorder." (quoted from dictionary.com)

Unpleasant - "not pleasing" (quoted from dictionary.com)

Pleasant (pleasing) - "Giving or affording pleasure or enjoyment; agreeable" (quoted from dictionary.com)

Based upon current scientific studies and evidence, the brain of a tarantula is not capable of producing emotions of pleasure or enjoyment or their opposites. Thus, in the strictest definition of pain, they do not experience pain.

When a human being experiences pain it begins with the stimulation of nerve receptors (unlike our other senses there are no specific nerve receptors for pain) a signal is then sent along a nerve pathway to the spinal cord. Upon reaching the spinal cord two things happen, one: the spinal cord sends a message back to the motor neurons near the site of original stimulation causing a reflex in which the muscles are activated and the site is pulled away from whatever stimuli caused the original stimulation. The reason for this is that signals travel slowly along the nerves (anywhere from two to 200 mph) and a reflex response helps prevent further injury that could possibly occur in the delay that it takes for the impulse to travel to the brain, be interpreted and then a message travel back with the appropriate response. Now, before that message reaches the brain our body has already taken steps to prevent further potential injury all before we have experienced the sensation of pain. And two the spinal cord continues the message along to the brain where it is interpreted as pain.
The gate-control theory is a theory that there are "gates" in the spinal cord that can either block the flow of signals to the brain or allow them to pass and that these gates may also be controlled by the brain. This theory helps explain why some people can suffer traumatic injuries and experience little to no pain. It also explains why rubbing the site of injury or applying ice helps control the pain, by sending competing signals to the brain the gates for pain are closed to allow the passage of the competing signals.
Pain is also very subjective, in a study by Craig and Preaching (1978) a group a volunteers were exposed to a series of electrical shocks and then asked to rate the discomfort experienced, half of the volunteers experienced their shocks in the presence of another person who supposedly received the same shocks and announced a rating of 25% lower than the rating stated by the subject, the other half received their shocks in the presence of another person who did not announce their ratings out loud. The first group, when exposed to information indicating that their partners experienced a lower level of pain, reported significantly less discomfort and actually showed a lower physiological arousal in response to the pain, indicating that pain is strongly affected by social or cognitive factors.
Then there is the interesting phenomenon of phantom pain, pain or discomfort suffered by an amputee in an area of the body that is no longer present. This also provides overwhelming evidence that pain is in the brain, provided with no stimuli the brain is still able to "produce" pain.
The bottom line is that spiders along with countless other species do not appear to have a brain advanced enough to perceive pain. The logical answer would be that spiders have a system in place similar to our reflex response, thus they respond in a manner that is self-preserving but do not experience the unpleasantness of pain that we experience.

 

[Code Monkey]

The gate-control theory is a theory that there are "gates" in the spinal cord that can either block the flow of signals to the brain or allow them to pass and that these gates may also be controlled by the brain.

This relates to invertebrates which have a limited number of possible responses. The flight reflex in the fly I gave above is one such example. In light, any motion stimuli occuring near the fly and the legs extend causing the fly to leap off the surface and flight is initiated long before any signal reaches the fly's brain. However, if the optic centers of the brain say it's dark, a signal from the brain shuts off this reflex by blocking the ganglion connected to the locomotion nerves. By and large, there is a rather limited number of possible outcomes to any particular stimuli based upon the interaction of inhibitory and stimulatory signals coming into the various ganglion in charge of the invert's response.

You can even create very detailed flow charts for even seemingly complex behavior that demonstrates where these branch points are demonstrating no actual complexity of processing. As an example, it might seem to be pretty complex behavior for a wasp that digs a hole in the ground, lays an egg and then stocks the hole with paralysed prey items for the grub, finally filling in the hole and tamping off the dirt. However, all of this is triggered behavior that stems from the original oviposition.

For instance, fill in a bit of the hole after the wasp digs it and leaves to get the first prey item before laying the egg and the wasp will come back, notice your alterations and re-dig to the proper dimensions. Now, artificially shorten the hole after the wasp lays the egg and it never notices. It fills it up with an insufficient amount of food, seals it, and goes on its way even though the larva is doomed to starvation. At the opposite end, you can continually remove the prey from the hole (this works with some dung beetles as well) and the wasp just keeps chucking prey in there never stopping to think about why it's taking so many trips to fill the hole.

Invertebrate behavior and physiology is fascinating, or I wouldn't be in graduate school studying entomology, but it is an error in judgment to attribute sophistication to them that isn't there, and wouldn't do them any good even if it was.

 

[MizM]

...Pain - "An unpleasant sensation occurring in varying degrees of severity as a consequence of injury, disease, or emotional disorder." (quoted from dictionary.com)

Unpleasant - "not pleasing" (quoted from dictionary.com)...

They experience SOMETHING that triggers them to take evasive action from the negative stimuli. It might not be pain in the literal sense, but they feel SOMETHING. We can argue the theoretics all day long, but I prefer to operate on the assumption that their "trigger" is unpleasant to them. Pain is only a term in this case, shortening the phrase "SOMETHING that triggers them to take evasive action from the negative stimuli".

There is no way that we will ever know WHAT it feels like to them, or even if they "feel". All the science in to world won't make it possible for us to attribute anything to Ts that we can't experience ourselves.

 

[Code Monkey]

There is no way that we will ever know WHAT it feels like to them, or even if they "feel". All the science in to world won't make it possible for us to attribute anything to Ts that we can't experience ourselves.

That's simply not true, but if someone is bound and determined to attribute the impossible to tarantulas there's only so much banging our heads against the wall we can do. You can't have things both ways, believing in all the amazing brain mapping we've managed to do in invertebrates and vertebrates, including humans which lets us absolutely confirm hypotheses with your "experience requirement", and turn around and claim we can't know they lack awareness when it suits your emotional needs.

 

[Tony]

just add :wall:

 

[SpiderDork]

Pain is only a term in this case, shortening the phrase "SOMETHING that triggers them to take evasive action from the negative stimuli".

"This forum is for scientific discussions and questions pertaining to Tarantulas"
The previous quote is the explanation provided for the purpose of this forum.

The vocabulary of science (whatever discipline you practice) is filled with words that have very specific meanings. The reason for this is that scientist can communicate with one another with little to no confusion.

If this forum is to live up to its claim then we cannot arbitrarily assign definitions to words as we see fit, it will only lead to confusion and a breakdown in the communication of ideas. This is why I provided the definitions at the beginning of my post, so that there would be no misunderstanding.

The "SOMETHING that triggers them to take evasive action from the negative stimuli" is very similar to the reflex response that I described and Code Monkey elaborated upon. If the "gates" in our spinal cord are closed and prevent the impulse from reaching the brain then we will react defensively without any perception of pain. All evidence reveals that negative stimuli in inverterbrates stops at the reflex point and goes no further.

 

[MizM]

That's simply not true, but if someone is bound and determined to attribute the impossible to tarantulas there's only so much banging our heads against the wall we can do. You can't have things both ways, believing in all the amazing brain mapping we've managed to do in invertebrates and vertebrates, including humans which lets us absolutely confirm hypotheses with your "experience requirement", and turn around and claim we can't know they lack awareness when it suits your emotional needs.

Repsectfully disagree. Even humans feel pain to different degrees, so how can we KNOW what others feel? I had both children without a drop of painkillers, I've got friends who couldn't stand stage 1 labor.

How do we know what a T FEELS when burned by the sun? How can we say the stimuli it receives doesn't "hurt" as such?

I really, truly believe that we simply cannot know EXACTLY what they "feel" and EXACTLY what they "think" (putting on nad protection ). We can only hypothesize until we're blue in the face.

 

[Code Monkey]

I really, truly believe that we simply cannot know EXACTLY what they "feel" and EXACTLY what they "think" (putting on nad protection ). We can only hypothesize until we're blue in the face.

Because we know they don't have anything to feel with - you needn't figure out someway to obliterate your mind by placing it inside a nervous system that lacks any awareness to know what *no awareness* "feels" like: no awareness = no suffering.

I honestly do not understand why this topic comes up, I honestly do not understand why there is debate. If someone insisted that Ts could learn language I hope that no one here would agree. Yet how do we *know* they can't learn language, oh yeah, no anatomical structures for it. How do we know they can't fly, oh yeah, no anatomical structures for it. How do we know they can't shoot lasers out of their spinnerets, oh yeah, no anatomical structures for it.

Yet when it comes to this emotionally laden subject, suddenly there is all this room for debate with people. Suddenly the whole of neurophysiology and behavioral science is inadequate even though its how you accept such basic facts as the limited colour spectrum seen by dogs or cats - it's not like we asked them, we jammed probes in their brains and nerves and measured when they fired and in response to what. And when it comes to inverts, their nerves have been poked and prodded millions of times over - there's nothing there that indicates anything required to suffer, but yet you'll still fall back on your "we can't know" even though we do know for all intents and purposes.

If you think there is even a slight chance your tarantulas have awareness enough to suffer from negative stimuli, then the same goes for the crickets and roaches you feed them, the same goes for the mosquito on your arm you just smashed, and the same goes for the fleas on your dog. And if its the fact that they respond and avoid negative stimuli that opens this doubt for you, then please throw out your bleach and soap, because you can get flagellated bacteria to move towards positive things and away from negative things for them, clearly they might be aware and suffering from our actions as well

 

[danread]

Thats probably the best post i've seen on the topic so far. Well put CM!

 

[MizM]

So you are essentially saying that if you hold a T over a flame and let it burn to death slowly, it wouldn't feel anything that we could tranlate to be discomfort? I really find it hard to believe. I just can't imagine it. There has to be SOMETHING.

 

[cacoseraph]

So you are essentially saying that if you hold a T over a flame and let it burn to death slowly, it wouldn't feel anything that we could tranlate to be discomfort? I really find it hard to believe. I just can't imagine it. There has to be SOMETHING.

you would overload its various sensors and likely trip a strongest escape response... the sucker would squirm until you boil-popped it... but i honestly don't think it's brain would be registering pain.

but the reactions the spider would exhibit would be indistinguishable (more or less) flame cooking a person or monkey or maybe even one of those super basic slime worms

bear in mind, i love animals... i keep bugs cuz it was too like, traumatic for my mammals & other furries to die on me... but i don't think the spiders are sophisticated enough for emotions... just sensor conditions that must be met with macros of response behavior to alter environment or self to satisfy those conditions

 

[Code Monkey]

So you are essentially saying that if you hold a T over a flame and let it burn to death slowly, it wouldn't feel anything that we could tranlate to be discomfort?

This conversation with you is boiling down to arguing semantics about what we mean by discomfort and pain, but what I believe is relevant is what would invoke an ethical response from us, that is something that is emotional discomfort within the tarantula's nervous system, and as for that, there is nothing.

Assuming you had a reason to kill a tarantula, I would no more consider it unethical to burn a tarantula to death slowly than I would to use CO2 to knock it unconscious and administer an overdose of whatever passes for euthanasia fluid for a spider. There simply isn't any "mind" there to mind what's being done.

On the older boards in another of these nigh pointless back and forths I said something akin to:

The question isn't whether or not a tarantula can sense pain, the question is what do they think about it?

And that is the whole point of all this bantering: does a tarantula have a mind to speak of that can suffer, can have real emotional discomfort? Science tells us that although we haven't ferretted out what every single ganglion in invertebrate brains is responsible for that there isn't any sort of interconnected mind present, i.e., it doesn't think in any way that is ethically relevant. Your tarantula isn't suffering when it's chock full of nematodes or bleeding out from an abdominal rupture any more than your computer is when it's got a virus and Norton is going mad with the screen popups telling you of its distress.

 

[defour]

Interesting post. The rest of the thread probably has some good stuff in it, too, but my attention span isn't long enough for all that.

Because we know they don't have anything to feel with - you needn't figure out someway to obliterate your mind by placing it inside a nervous system that lacks any awareness to know what *no awareness* "feels" like: no awareness = no suffering.

I'm not sure if I'm reading this as you intended it, but the idea of knowing what "no awareness" feels like is incoherent. It presupposes conciousness.

how do we *know* they can't learn language, oh yeah, no anatomical structures for it. How do we know they can't fly, oh yeah, no anatomical structures for it. How do we know they can't shoot lasers out of their spinnerets, oh yeah, no anatomical structures for it.

On paper, this is good. When it comes down to nuts and bolts, or tacks and screws, or corks and paddywhacks or whatever the proper hardware is, we know all these things because we have gloriously strong inductive arguments to support them: tarantulas can't learn languages because we've never seen one do it, and things get bootstrapped up a bit at a time until we seem to have nice physiological underpinnings to point to. We've never seen chimps speak, so we assume they can't. With that in mind, we investigate all the details of their anatomy and not surprisingly, come up with evidence to back it up. It works, more or less. I suspect, however, that if crows had not been observed to mimic mechanical noises and human speech, someone would have looked in their mouths and declared 'this apparatus is incapable of producing the Queen's English', in the unlikely event that they would even have considered such a thing.

Yet when it comes to this emotionally laden subject, suddenly there is all this room for debate with people. Suddenly the whole of neurophysiology and behavioral science is inadequate...

I agree completely. This kind of opinion is almost always emotionally driven, except perhaps in epistomological circles (which may not matter to a scientist, since they're often openly hostile to philosophers).

If you think there is even a slight chance your tarantulas have awareness enough to suffer from negative stimuli, then the same goes for the crickets and roaches you feed them, the same goes for the mosquito on your arm you just smashed, and the same goes for the fleas on your dog.

I agree again. The interesting thing about all this is not the question of where you draw the line, but whether or not you can. As a scientist, you have to pick a spot and make your line or you'll get bogged down and never get any work done. Some scientists, if you look over their shoulders while they're engaged in line-drawing and ask them about it, will say that they really don't know what the exact deal with the lines is, but they do it because they have to. Others will growl and hiss and get red in the face and then stomp off to their offices. There are fewer of the latter today than there were a century ago, I think. Ultimately though, it's just a fun game. Science is about results, and as long as they're coming in, questions like this really don't matter. Philosophy may be fun, but you'll never build a decent rocket with it.

Steve

 

[edesign]

So you are essentially saying that if you hold a T over a flame and let it burn to death slowly, it wouldn't feel anything that we could tranlate to be discomfort? I really find it hard to believe. I just can't imagine it. There has to be SOMETHING.

well...just because you can't imagine it does not mean it isn't so. A lot of people can not fathom the idea that after death there is nothing...nonexistence. Try it some time if you haven't, try to imagine yourself not existing...no memories, no thought, no senses...nothing. Can't do it can ya? Doesn't mean it's not a possibility and doesn't stop people in believing there has to be an afterlife because the idea of nonexistence is unfathomable.

There IS something...and that's what some of you who are taking the stance that inverts (t's in this thread) can feel pain are incorrectly processing. Think about your reflexes...when the doctor taps below your kneecap your leg kicks, when someone/thing frightens you unexpectedly you react LONG before your conscious brain has any idea of what is going on, these are examples of what happens with T's and their nervous system. It's merely a signal that tells the T how to react...there is no positive/negative feeling associated with it...it is simply THAT, a signal. Think of them like little computers (i forget who said this first in this thread, i know CM alluded to it), they are basically a software program that has been programmed through eons of evolution.

10 IF hairs sense strong vibration
20 THEN run
30 OR if run is not possible
40 THEN display threat pose
50 WHILE in threat pose
60 IF threat gets close
70 THEN lunge at threat
80 IF threat leaves
90 THEN GO 110
100 ELSE GO TO 50
110 RETURN 0 (return zero meaning end program)

something like that...it could be coded even closer to computer code but i wanted it to be understandable. There is no positive/negative associated with the stimulus...it's simply reacting.

 

[Code Monkey]

I'm not sure if I'm reading this as you intended it, but the idea of knowing what "no awareness" feels like is incoherent. It presupposes conciousness.

That was sort of the point. If you've ever been totally knocked out for surgery you know how much suffering your tarantula is capable of

On paper, this is good. When it comes down to nuts and bolts, or tacks and screws, or corks and paddywhacks or whatever the proper hardware is, we know all these things because we have gloriously strong inductive arguments to support them: tarantulas can't learn languages because we've never seen one do it, and things get bootstrapped up a bit at a time until we seem to have nice physiological underpinnings to point to. We've never seen chimps speak, so we assume they can't. With that in mind, we investigate all the details of their anatomy and not surprisingly, come up with evidence to back it up. It works, more or less. I suspect, however, that if crows had not been observed to mimic mechanical noises and human speech, someone would have looked in their mouths and declared 'this apparatus is incapable of producing the Queen's English', in the unlikely event that they would even have considered such a thing.

The weakness to this semi-counterpoint is that neurophysiology started with inverts and built up from there. We didn't start "taking apart" chimps and prison volunteers and work backwards, we figured out how the nerves work by poking and prodding the inverts. We aren't claiming that the tarantula doesn't feel pain just because we don't find the same thing in them as a human, we claim it because everything in the tarantula, in a sense, is in the human and it's the extra bits that have been empirically demonstrated to be used for the sort of higher mind functions necessary for emotional awareness.

 

[Nia]

It seems fairly obvious to me whether or not any creature, especially Ts since this is the topic, feel pain. You have observed that Ts do have a fight or flight response... Why? If they dont feel pain, then why would they want to fight or run away? Pain, and the fear of pain, is the factor that motivates, not only humans but other creatures as well. Just because we can not see or hear them react in a way that humans or other mammals do does not mean they are not communicating their fear of pain, or when they are in pain. Yes, all creatures have an understanding of pain, though they may experience it in ways that we are unaware of. They have even scientifically proven that plants respond to pain <http://www.department13designs.com/vegan.html>.

At one time (and even now in many third world countries) it was believed that women did not have souls and did not really feel pain... whether or not other creatures feel pain? Isn't that just as silly? IMO

 

[C_Strike]

AS far as i'm concerned, a tarantula as with all forms of life have an iinbuilt self-preservation technique, be that a true neurosystem or what ever. whether it is in comparison to a mammals advanced neuro-network or not, they will feel pain as with a sense of hunger/thirst..etc,etc... i think it is a basic innate responce to pressures of the environment. they obviously have a different resonse to a cricket than a stick (in all my experience), a tarantula might become defensive/aggressive towards the stick btu will generally either munch onthe crik or pretty much ignore it. This difference of response surely dentes that a tarantula can distinguish between certain things which in turn shows this self-awareness/self-preservation. i have a video documentary about Theraphosa b's. It contains footage of a south-American tribe killing and eating 1.
they used a sharp stick to pierce the underbelly of the spide
The spider had a very blatant response to this... its legs wildly twitched and it rapidly, and futily, tried to tag the tribesman. This is a sure response which surely shows that tarantulas are aware of themselves and have,even if very basic, .
ANYthing which will twitch if ya decide to ram a stick through it is showing distress...
We can feel objects with our fingers, on some level this is pain...we are aware of pressure on our fingers, though it isnt considered 'pain' unless it hurts... but it is still the very same kinda of sense
...longwinded i know, but i struggled to explain myself,lol

PS: probably doesnt make a whole lotta sense, i have confused my self several times through writing this

 

[Code Monkey]

Thought experiment time for those that just can't wrap their heads around a simple idea:

Let's say that Bob is a recent paraplegic, paralysed somewhere midchest by a traumatic spinal cord severing. If I jam a nail in Bob's foot does he feel pain?

Anyone say yes? Anyone?

Right, he doesn't feel pain because the parts of his aware nervous system that are responsible for *feeling* pain never get the signal to interpret as pain even though it is being sent. More importantly, even though it doesn't do any good, the ganglion at the base of the spine are sending back "get the hell out of dodge" signals to the legs and if Bob were a tarantula or a cockroach he'd be thrashing all over the place severed spine or not.

Now here's the intellectual leap for people to make: the tarantula has no part of a brain for feeling pain for these signals to get to in the first place. It's that simple.

You can argue emotionally crippled pseudoscience all day long, it won't make a case.

:wall: :wall: :wall:

 

[SpiderDork]

At one time (and even now in many third world countries) it was believed that women did not have souls and did not really feel pain... whether or not other creatures feel pain? Isn't that just as silly? IMO

These beliefs were culturally founded not based upon years of scientific study, thousands of experiments and scientific fact.

Making a comparison between flawed cultural beliefs and scientific theories is meaningless.

We can believe whatever we want, that is one of the wonderful things about the human mind, the only one who can change it is you. But that doesn't mean we are always right. I can believe 100% that I can fly without mechanical assistance, but the moment I make the attempt the laws of physics (gravity in this instance) assert themselves and despite my "beliefs" my flight will come to a sudden and most likely tragic end. Beliefs are great but in the world of science beliefs without facts and evidence are next to meaningless and are unlikely to be taken seriously. This is allegedly a "scientific" forum so don't be too disappointed if your beliefs are not taken seriously or challenged because they lack merit. Remember, it's not personal it's just good science.