Dear Students!
Here is
the reading assignment for our next seminar on the 4th of March! Our
speaker will be Tom Schoenemann and he will be talking about the
evolution of brain and language:
P. Thomas Schoenemann (2012) Evolution of brain and language
Don't forget that your blog comments are due by 9am on the day of the seminar!!!
On page 451, I found it interesting that Brodmann area 13 is only ~1.5 times larger than the average ape, while many other areas of the brain responsible for language were at 4-7 times the average. Furthermore, this is the area that is responsible for "assessing emotional aspects of social interactions." Given that many people praise humans for their rational capacity, and many discussions of social cognition, until recently, have favored more intellectualized approaches (see Theory Theory and Simulation Theory vs. Interaction Theory and direct perception), I can't help but find it interesting that the area of the brain responsible for assessing emotional aspects of social interactions is also smaller than the more rational/conceptual parts. Further, given the extreme necessity of emotional processing in social contexts, why might it be that this section of the brain lagged behind? Was it simply that rational capacities happened to be those that enlarged due to random/natural selection, relative to emotional ones, and that the rational capacities were then able to eventually compensate for the lack of emotional processing?
ReplyDeleteAlso, as a side note, since the authors claim that "language adapted to the brain more than the reverse", is it possible to concede that perhaps language is a sort of epi-phenomena/emergent phenomena that appears when increasing complex brains/processing systems arise amongst one another? Thus, it's not so much that they co-evolved, in the same way that two species might co-evolve in an environment, but rather, the development of a complex brain system and the need to communicate to other complex brain systems necessitated language and that the course of evolution past this point is simply constrained by how fast language can adapt? Perhaps the answer is obvious and this is what we've been discussing all along, or maybe I did a poor job conveying my point, but the terms "co-evolve", in the strictest sense, does not seem to capture my idea. Perhaps I'm totally in the wrong, though.
I have two general questions, respectively stemming from the idea of neural reuse and possible teleological explanations of co-evolving features. First, to what extent do mechanisms of neural plasticity and neural reuse either support or trouble the ultimate aim of an evolutionary story, here, from a comparative perspective? For instance, consider the case of sensory substitution devices. The ability for these devices to bring about results in such a short timescale seems to have an implication for the evolution, or at least development, of neural structures at a rapid rate and in response to changes in the perceptual sphere. Such changes seem to raise interesting possibilities in regards to anatomical constraints in the case of language evolution.
ReplyDeleteSecond, one of the questions for the target article concerns the role various systems and subsystems play in the evolution of linguistic capacities. As noted by the author, however, it is often the case that while "[t]hese changes are certainly relevant to language evolution, though knowing whether they evolved specifically FOR language, rather than to support more general cognitive operations involving conceptual understanding, is unknown" (450-1). While I find this question and response unproblematic, I wonder if the interactive, dynamic, and co-evolving status of the various systems at play entails ramifications for the use of a conceptual toolkit developed towards more linear ideals of evolution. Insofar as the organism (and species) is evolving in a dynamic environment, wherein the environment is changing and shaping the evolutionary pressures for the organisms at the same time as the organisms are reshaping the environment and creating different sets of evolutionary pressures, what role do questions of what the organism is best suited for play in this dynamic context? Or, in other words, how does the dynamics of the process being explored in this paper relate to a broader issue concerning the role of teleological (i.e. end or purpose-based) explanations in cognitive science, particularly from an evolutionary and comparative perspective?
This comment has been removed by the author.
ReplyDeleteThe idea that "the coevolution of language and brain can be understood as a complex adaptive system(p.444)" was well-reviewed in this paper. What I found interesting was the effect of neuronal spatial organization. As written in page 453, though both humans and apes have shown asymmetric in the planum temporale, only humans seem to show the differences in neuronal spatial organization. Thus, the important factor on brain function may be more related to neuronal spatial organization than relative sizes.
ReplyDeleteIt was interesting that not only classically well-known Broca and Wernicke area, but also many other brain regions highly involve in language processing. They participate in communication processing having their own specific role for it. They provide useful information on origin of language in the view of brain evolution. Evolution of different particular brain areas has been progressed differently in size. These descriptions are facts proved from scientific observation, so everything is acceptable to me.
ReplyDeleteThe author’s main argument is that language appears to have adapted to the human brain more so than reverse. If I understand correctly, cultural evolution has more influence on biological evolution than vice versa? Cultural evolution isn’t a factor of biological evolution?
This isn’t a question so much as a connection. The section on vocalization seems to corroborate last week’s discussion. They talk about how vocalization is enervated in the brainstem; however, the brainstem nuclei don’t appear to be proportionally bigger in comparison to other close primate relatives. For primates, this impulse to vocalize is mediated by areas of the brain associated with emotion, but for humans, there are strong direct connections to other parts of the brain involved with semantics, grammar, respiratory control and tongue/jaw control. This suggests that we have a broader neural circuit and higher control over the signal, however the area that generates the impulse to vocalize remains quite the same as it was in our earlier evolutionary history.
ReplyDeleteThis seems to corroborate the story that we got last week about marmoset vocalization, specifically in the sense that the impulse to produce vocalizations appears to be a more primordial feature of neurological architecture, and it develops semanticity once the right sort of pathways and circuits of mediation have been developed. What do you guys think?
This comment has been removed by the author.
ReplyDelete"Human social networks appear to be particularly complex,and given that language is an inherently social activity, the selective value of language is likely greatest for humans (p. 446)." I found the positive correlation between brain volume and group size interesting. As man has become more socially dependent on learning, the need to communicate could have increased. Social groups provide a basis to pass on information, especially generationally. Each group would then attain stronger language skills as time passes. Could language have transitioned from the social grooming of our primate relatives to language use? This language use could be both a social in function and more an efficient use of time.
ReplyDeleteThis article provides an interesting perspective to me because I often think more “language adapted to the human brain (cultural evolution)” than “human brain adapted to better subserve language (biological evolution, p.444)”. The article also concluded “language adapted to the brain more than the reverse”. But if biological evolution plays a more important role than culture evolution, what would happen? Would humans’ cognitive abilities be different across speakers of different languages or all the languages have similar degrees of complexity? Another question is that the could we say the biological evolution is more applicable to infants’ or young children's brains because they adapted to learn languages?
ReplyDeleteI apologize for being late. Schoenemann's chapter is broad and inclusive, providing more than just a single experiment or argument. Overall, Schoenemann posits that language has adapted to the brain more so than the brain to language. This is supported in that the brain structures involved in the various processes of language use and production also exist in non-human animals, while our language use is much more complex. One telling indicator, though, is that size of brain in relation to body mass is well correlated with group size per species. This suggests that as our social interactions become more complex, we have more to think about, and increase in brain mass becomes a reproductively adaptive trait. We may also with increased group size have increased defense from external predators, allowing us to focus on internal social interactions of our own species.
ReplyDeleteSchoenemann details quite a few areas of the brain and neural connections, delineating their role in various aspects of language use and processing. While Brocce's and Wernicke's areas are known for some specific contributions in fluency and grammar, brain areas for specific physical acts such as controlling the vocal cords and lungs are also included. This description is thus not minimalistic but includes a broad scope of brain interaction with language.
Non-human animals have the same brain regions, but with different relative and absolute sizes than found in humans. So in our understanding of which came first, the chicken or the egg, the brain structures came first. These structures have continued to evolve, ie, biological evolution ~ as language has evolved, ie, cultural evolution, in a synergistic manner.
Language evolution has been constrained by the social environment as well as by brain capacities. Schoenemann argues that language is not functional unless it can be mutually understood among members of a species. This makes one wonder how advances in language have occurred at all.