Barbara Finlay Continuities/Discontinuities in Vertebrate Brain Evolution and Cognitive Capacities: Implications for Consciousness?
Abstract: Comparing the evolution of consciousness and its contents to the structural evolution of the brain often runs aground on basic misunderstandings about brain scaling. Because the neocortex appears 'oversize'ï¿½ in humans, for example, the presumption that the cortex must be the structure critical to multiple aspects of human cognition and consciousness is ubiquitous. Demonstration that humans have exactly the relative volume of cortex expected for a primate of our brain size demands explicit discussion of when discontinuities in awareness should be proposed when no structural discontinuities exist. When developmental homologies between vertebrate brain parts are established, and the allometries of neurons and networks are well described, true 'discontinuities'ï¿½ in brain structure prove to be very rare. Yet, there are occasional substantial reorganizations of brain connectivity that may shed light on the contents of consciousness. The reorganization of viscerosensory representation in insular cortex in large primates may enable basic changes in the perception and communication of pain and distress, a phenomenon I will term 'the pain of altruism'ï¿½.
Syal, S. and Finlay, B.L. (2011) Thinking outside the cortex: Social motivation in the evolution and development of language. Developmental Science 14: 417-430 DOI: 10.1111/j.1467-7687.2010.00997.x http://people.psych.cornell.edu/~blf2/pdfs/SyalDS11.pdf
Charvet, C.J. and Finlay B.L. (2011) Embracing covariation in brain evolution: Large brains, extended development and flexible primate social systems. In Evolution of the Primate Brain: From Neuron to Behavior, in M.A.Hofman & D. Falk, eds., Progress in Brain Research 195: 71-87. http://bit.ly/FinlayBrainEv
Thank you very much, Prof. Finlay.ReplyDelete
I wonder if some of your points can be teased apart a little bit.
Granted that we have a lot of thoughtless corticocentrism, it seems to me that based on converging brain recording measures, including fMRI but also direct cortical recordings, in humans and other primates, that the cortex and thalamus enable the moment to moment CONTENTS of consciousness, such as reportable perceptual events. These can be assessed in other animals by match-to-sample tasks.
That does NOT mean, obviously, that subcortical and subthalamic regions make no contribution to conscious contents, but only that those contributions are "realized" or "specified" in the thalamocortical core, as argued by a number of neurobiologists. If somebody steps on my toe peripheral neurons in my toe contribute to my consciousness, but that signal is interpreted as conscious pain in thalamus and cortex, but not peripherally, though pain neurons pick up that signal quite early. Identifying a stimulus as pain may happen peripherally, but conscious appreciation of that event as pain may happen in the thalamocortical system. An early PET study by Rosen, Frith et al suggests that kind of interpretation.
That would suggest continuities rather than discontinuities, with the border of conscious perception moved quite a bit earlier than is often assumed, at least to early mammals or ancestral reptiles. I hear this from Gerald Edelman among others.
Since the enlarged neocortex and thalamus appears in early mammals and maybe ancestral reptiles, it would seem that perceptual consciousness, for example, predates primates and perhaps predates highly social vertebrates.
That line of evidence might mean that the growth of cortex enables complex and flexible social cognition in primates, rather than vice versa.
With the expansion of the frontal lobes we get language and what Gerald Edelman calls "higher order consciousness." But consciousness "as such" might be quite a bit earlier.
Panksepp and others certainly make a strong case for the PAG, but they do not (to the best of my knowledge) make a case that sub-thalamic structures support conscious contents in humans. Infant-mother bonding in humans certainly activates insula, medial cortical, orbitofrontal, and similar regions. Insula is a good candidate for conscious interoceptive emotional feelings. I'm not sure if that case can be made for deeper brainstem areas, AT LEAST in humans.
To say that information is processed or represented in some neuronal structure is not to say that it is necessarily conscious, of course. The quick and dirty test is whether it's accurately reportable.
Finally, if I can pick one small nit --- altruism is a wonderful feature of our brains, of course, but the same cognitive capacities would also seem to underlie the opposite kind of emotions: Namely cruelty or Schadenfreude. Children are often very un-self-conscious about displaying those feelings. Cruelty based on accurate theory of mind cognition about other minds would seem to be a pretty awful but still real feature of human cognition.
I'd be grateful for your thoughts.
Thanks for your response! I agree fairly thoroughly with the whole first section, concerning phylogenetic stability. I am much convinced by Merker's argument about the roots of consciousness of the perceptual kind being rooted in the requirements of movement, building a world-self model. I think the evidence for the location generating the model being di- and mesencephalic is becoming fairly strong. But, in concord with your comment, I told Steven before the talk that I was talking about the contents of consciousness, not its presence. In the case of amplification of viscerosensory representation in the cortex, I'm imagining that this change would allow this information to be better located (by the experiencing individual) in the body, related in more detail to the environment, described verbally in humans, taken into account in planning and so forth, instead of primary pain and upset which might be experienced if the VM-insula pathway were not available.Delete
I agree entirely with your remark on cruelty -- the talk I gave pasted together the cortical comparative neuroanatomy and the pain argument. My longer pain version has a slide called "Faustian bargains" which might have been produced by this same system. Listed there are the deliberate intention (and ability) to produce pain; malingering and possible disorders of the pain-seeking response; and a similar pattern of evolution in domesticated animals because we could help them. Have you seen Victor Nell's article, "Cruelty's rewards: The gratifications of perpetrators and spectators" BBS 2006? It's one of my favorites. I haven't thought much as yet about how to functionally integrate the two as yet.
Finlay highlights that the differences between human brains and other mammals are relatively small. Given these similarities, to me it sense to assume that other animals have a consicousness that is also relatively similar to ours until proven otherwise.ReplyDelete
correction: *it sense* --> *it makes sense*Delete
It is true that Pr. Finlay showed that many properties of the human brain are not a discontinuity as they are predictable (e.g. the relative size of brain regions is predictable since it increases linearily as the brain size increases... and she gave other examples of predictable properties). However, she did not argued that human consciousness is similar to animal consciousness. Intead, she insisted that pain enables to exhibit advantageous actions in relation to a wider and more complex set of social goals and stimuli (e.g. helping others and seeking help from others). Most importantly, this use of pain is not totally predictable, that is, the diversity and complexity of social goals and stimuli do not increase linearily as a function of other predictable variables (e.g. brain size). Thus, Pr. Finlay concluded that the social functions of pain in humans could account for human singularity. Even though other animals use pain for social purposes, this use is far less sophisticated than that of humans.Delete
Exactly. To argue that consciousness has continuity is not to argue that that its domain, or the differentiation within domains are the same. I often think rather simplistically of major brain divisions as performing a general sort of operation, the isocortex a Hebbian correlator generating statistical relationships and structures; the cerebellum error-driven and so on. Just as those operations span entirely different domains of experience in a trout or a giraffe, so will consciousness be operating over different domains.Delete
The main message I took from Dr. Finlay's talk is that humans are wimps! I wonder if complaining also served some type of evolutionary advantage...ReplyDelete
Surely it does!Delete
As a highly social species, all our behaviors evolved to cope with this socially constrained and complex environment and all our behaviors are at some point adaptive and socially inluenced (socioculural approach)included complaining. Why do you think complaining is associated whith some specific "vocalizations" (if I can say so!) and facial expression? because it has to be communicated to other individuals. Seeking help is really adaptive at the individual level. By seeking help you can aquire resources for survival when your life is threatened and your condition doesn't allow you to do so. Pain recognition is also part of empathy which is itself highly adaptive for social species as ours.
"Complaining" is a dichotomous concept that does not account for the complex way humans use pain in social contexts. I would agree that humans sometimes show signs of distress that are dispropotionate (e.g. someone who would feel mild negative emotions but that would exhibit high signs of distress). Nevertheless, when humans "complain", this is most often accompanied by negative emotions. Thus, humans rarely show pure complaining. For your second sentence, "complaining" has evolutionary advantage for the person who complains since it enables him to receive more help. In some psychopathologies, complaining can show adaptive value to some extent. Specifically, some people seek help to compensate for the fact that they lack emotional and cognitive auto-regulatory capacity.Delete
Yes Félix you're right. More and more evidence tend to demonstrate that psychopathologies may have an evolutionary history and were at some point adaptive in a certain kind of specific environment. Seasonal affective disorder for instance (winter depression) shows interesting evidence that make us think that depressive disorders might have an evolutionary origin and that the evolutionary advantage relies on help received from others.Delete
No, I really don't think I argued anything that would support that humans are wimps; the argument is actually the opposite, that humans are subject to more experienced pain, because to do so may give them the advantage of being helped (and I don't mean treated medically, or having their pain treated, I mean being protected, provisioned, provided basic comforts).Delete
I do find myself very uncomfortable, however, with finding an adaptive account of every possible illness. In evolutionary medicine, there is so much to do in sorting out what is an adaptation, who the adaptation belongs to (for example, a the upper respiratory symptoms of a cold are in support of the cold virus's genome, in that the virus is broadcast and is not damaged by sneezing); and finally, what is simply pathology. I like Matthew Keller's take on this (Resolving the paradox of common, harmful, heritable mental disorders: Which evolutionary genetic models. with Miller, BBS06 and further works).
I liked Barbara talk, but I can't see the connection between his model of 'the pain of altruism' and the consciousness.ReplyDelete
She does not explain the causal role of feelings nor does she explain the neural correlates of feelings. She talks about what functions make human singular.Delete
It's all about communicating the pain. Pain and distress allow humans to seek help from other individuals. I know some people would say that communication doesn't need consciousness to be effective, but in the human context, pain communication cannot occur if at least the helper is not conscious to perceive the other's pain. I think here, pain illustrates nicely how any human behavior is so socially grounded and that all these could not occur without consciousness because it relies on human forms of interindividual communication either through language or other forms of communication involving senses (hearing, seeing, touching), meaning involving consciousness.Delete
There were two different arguments intermixed. I'm using the continuity of structure in vertebrates to build a case for the continuity of basic processes. In the case of pain in humans, I'm arguing for a distinct species difference, causing a change in behavior and the contents of consciousness.Delete
I really enjoyed Dr. Finlay's pain postulate. I'm not fully convinced, however, that other animals fail to display pain in order to elicit adaptive altruism from others. It is probably universally agreed that many mammalian infants display a type of needy behaviour (both in and out of pain).ReplyDelete
I recalled a recent(ish) Nature paper which looked at the ability of mice to convey 'facial pain expression'
If there is an overt display of pain, it is conceivable that this serves some form of communicative purpose, and it is plausible that this serves to elicit some form of response from other members of the same species.
This also makes one think... do other species attempt to 'extract' altruistic acts from others, but we as humans (with our limited capacities to communicate via the language of other animals) are just unable to perceive and/or interpret these social pain cues present in these animals?
You're right; everything has roots. I was suggesting that the source of continuity, certainly common to rodents and primates, was the mother-infant interaction, extended into the lifespan. I was really pleased to see a study just yesterday about the frequency of alloparental care (by both parents, other related individuals, and the whole group, but the target always young) - Isler, K., & van Schaik, C. P. (2012). Allomaternal care, life history and brain size evolution in mammals. Journal of Human Evolution, 63(1), 52-63. doi: 10.1016/j.jhevol.2012.03.009. You'll see a basic level across a lot of mammals, but a big difference in primates. Check it out.Delete
I really appreciated her anatomical work and although i am not a 100% convinced that everything is just more or less inflation in brain size, i think it is actually a good observation to know. One could argue now that given the anatomy is so similar also the functionality must be very similar or cannot be so much different (if you are very materialistic). However, what i find very interesting now to include the following thought to this: given the anatomy is so similar, there is still the possibility that new functions arise which were shaped maybe before by certain evolutionary developments, but took then a new function in the human mind. I am thinking now of Gould & Vrba exaptation or the neuroscience version of it by Dehaene's neuronal recycling hypothesis. So, either you argue for the very similarity between humans and other species and it is nothing more than a gradual development or you include the possibility of exaptation to create genuinely new functions which have striking new qualities than the precursor of it. Both maybe true and also the latter is a evolutionary principle. However, i think the latter is a meaningful view on the development of the human faculty.ReplyDelete
I'm a big fan of the exaptation argument; here I'll push another BBS article, Mike Anderson's "Neural re-use" paper, which I think is terrific. It's a mechanistic level down from the Dehaene one.Delete
The basic theory in brain allometry has always been Jerison's "proper mass" -- if you do a lot of "x' you have a lot of brain doing "x". Thus, people are constantly comparing, say, the amount of visual cortex in a nocturnal and diurnal animal, and attempting to show that the residual variation (the 1% after the 99% covariation is taken out) is related to "niche". Usually people have to massage the hell out of their data to show even tiny effects in this enterprise, and to my mind, this whole enterprise is just blown out of the water by observations like Mike Anderson's meta-analyses showing that primary visual cortex is involved in a whole number of non-visual tasks, and the observation that primary visual cortex comes to be involved in Braille reading in the late blind. By the way, note how this approach persists in fMRI -- a couple voxels more activation in the insular cortex is what causes you to be empathetic? I'd bet my last nickel that if you blew that spot (not the whole insula) out of the brain entirely, you would see no effect whatever on the capacity for empathy.
I think the better way to think about it is to look at the very real, large changes in primary motivational and affective systems, and see how the brain becomes populated with new information thereby.
Thanks. Yes i have also some of Anderson's papers where he used also the term "massive redeployment" which i find more descriptive than Dehaene's term.Delete
Interesting idea with the fmri, i have not thought about it like this. However, there are also observations like the one Cleereman mentioned where the size of v1 is correlated to the subjective experience. Also, motor learning studies show also something similar. But i agree that inferences drawn on imaging studies only is a bit doubtful.
Talking about that: i woild be very grateful if you could give me some more references on the insular to take down Craig's claims. I see his papers cited often, and it would be nice to have some more background on it. That would be great!
I think people have misinterpreted Dr. Finlay's pain hypothesis. The adaptive utility conferred by the alleged evolutionary expansion of the human capacity to experience pain can NOT simply be in our subsequent ability to ask for 'help' when in a state of suffering. Exactly what kinds of pain-relief methods do you think archaic hunter-gatherer societies had access to? Pain is largely untreatable even today, and this is only more true the farther back in history one looks. It is simply the case that there is very little 'help' one could possibly get for pain itself, so one has to look elsewhere for any putative fitness advantage.ReplyDelete
Rather, the survival advantage must come from the strengthening of social and emotional bonds engendered by Public Displays of Affliction, which then improve the group's ability to coordinate their activity when pursuing other survival ends in the future.
By the Wall placebo argument, the simple provision of any kind of help would reduce the motivational, find-help, component of the pain. I'm not imaging archaic hunter-gatherers initially producing any kind of medical help, they would just protect and provision. That would be an enormous advantage, compared to nothing!Delete
However, I think the interaction of the placebo effect and conditioning might likely be the initial cause of a lot of folk medicine across human cultures. For example, individuals with more power are more powerful in producing placebo responses when delivering medicine.
Très intéressant la théorie de Dr Finlay concernant la sensibilité à la douleur chez l'humain.ReplyDelete
Je ne crois cependant pas que seul les humains répondent à la douleur pour des raisons d'altruismes. Certains l'ont dit plus haut, certains animaux dont les primates répondent abondamment à la douleur de leurs pairs.
Est-ce que les gens d'aujourd'hui ont quantitativement plus mal que les générations précédentes ou que nos ancêtres primates? Je ne peux pas répondre à la question... Mais même au sein de notre présente société actuelle, il y a des gens qui sont (très) sensibles et d'autres moins.
Je comprends peut-être mal la définition d'altruisme utilisée dans la présentation, mais pour moi le concept relèverait plutôt d'une sorte de conditionnement...
Quelle est la meilleur façon d'obtenir de l'attention de nos jours?
Notice the citation in one of the above comments about the Isler and von Shaik data about which mammals and birds "alloparent", which they specify as simple protection up to direct provisioning. Primates do noticeably more than the other groups. Notice this is providing help and protection to juveniles in this case. I am sure a similar chart could be made with much reduced incidence, but not no incidence, for mature animals. The idea here is that humans got better at feeling and also expressing pain and distress, recognizing it, and responded with help. Notice, just "help", not medical expertise!Delete
Doctor Finlay’s presentation opens to the possibility of comparatively understanding the co-evolution of sociality and cognitive structures through comparative brain studies. By correlating social behavior with brain structure, and with phylogenic ancestry, we may be able to understand what gives rise to such complex phenomena as empathy and theory of mind. I find it fascinating that we could study the interplay of the enduring social organization of a given species in tandem with their cognitive adaptations to that situation.ReplyDelete
You should check out Jim Goodson's work -- the general characterization is that particular species of birds are made calm by their preferred social situation and anxious by its absence. It becomes easy to see how a genetically "loner" bird might move away from its natal flock, feeling "anxious" in a group; acquire different skills thereby and so on. It seems much easier to me to generate new cognitive skills via sociality than the other way around.Delete
Darwin described dogs as 'highly emotional humans'... they are very explicit with their emotions, pain joy, excitement, expectation etc, Now either they are doing this because of empathy as Barbara argues, or they feel more rather than less. Which one is it?Delete
Dr. Finlay's claim about the pain of altruism might be taken to have clear moral implications in animal ethics. The argument could go somewhat like this: “Dr. Finlay’s work suggests that (1) many animals experience painful sensations much less intensely (and for shorter periods of time) than humans do and that (2) our intuitions about what animals feel in specific situations might be mistaken if they are based on our expectations about what we would feel in similar circumstances. Even if some animals exhibit pain-related behavior in various situations, they might not actually experience painful sensations in many of those. We are thus justified in using animals for experiments or killing them unless we have specific reasons to believe that they experience painful sensations when we do these things.” (I am not endorsing this argument, I just expect that some people would make it.) What do people think?ReplyDelete
That would not only be (1) justifying hurting animals on a *theory* that they feel pain less but (2) *how much* less would justify hurting them?Delete
This is a question about the nature of a sensory experience, not of its intensity. If an animal is in pain, an animal is in pain. Proponents of your argument would be given a hard time with their affirmation that "many animals experience painful sensations much less intensely", because there is explicit recognition in that statement that animals can and do feel pain.Delete
Dr. Finaly explained that pain in humans has an evolutionary advantage through seeking help from others and therefore increasing chances of survival, while the experience of the same level of pain in other animals would not be evolutionarily advantageous. As has been mentioned in the above discussion there is evidence adult animals do communicate pain both facial and vocally. I was curious if there has been any comparison of experience of pain or the communication of pain in animals who live in a social community as opposed to primarily solitary animals?ReplyDelete
Xavier Dery @XavierDeryReplyDelete
I absolutely love Finlay's list of brain characteristics that change between species, reflecting what evolution changes the most. #TuringC
3:03 PM - 5 Jul 12 via Twicca Twitter app
Xavier Dery @XavierDeryReplyDelete
The fight against human exceptionalism goes on thanks to Finlay (and others of course) and consciousness should not be an exception #TuringC
3:48 PM - 5 Jul 12 via Twicca Twitter app
SIGNAL INJURY MORE INTENSELY, YES, BUT WHY FEEL IT?ReplyDelete
Lest we get too carried away with the idea that something has to be felt to be conveyed, remember that injury, detection, signalling and helping are all doings. A robot could learn (or evolve) to signal damage in order to elicit help from other robots. So something is missing here.
(The problem is the same as with the alleged evolutionary advantage of "self-deception" that was discussed in Dr. Finlay's journal, BBS:
Harnad, S. (2010) Deceiving Ourselves About Self-Deception Behavioral and Brain Sciences