Wild Replicator’s Got Funky Rhythm, Part 1

Now that the replicator meme is out and about I’ve got more to say. I’m going to republish two more posts from my 2010 cultural evolution series. These posts are about music. I have various reasons for using music as my cultural evolution conceptual sandbox. For one thing, it means that I don’t have to contend with semantic meanings arbitrarily associated with bits of music. In music, all we’ve got is the physical signal.

In these two posts I choose, not a simple musical example but, rather, a complex one, something jazz musicians know as Rhythm Changes. While I could talk about the four-note motif Beethoven used to construct the first movement of his Fifth Symphony, which is a memetic favorite, that’s too easy. Thinking about it won’t stretch our intuitions about the memetic properties of mere physical things. That motif has four notes, with specific durations and specific note-to-note pitch relationships.

Rhythm Changes isn’t like that. It’s an abstract property of a sound stream. There is now specific number of notes, no specific durations, and no specific note-to-note pitch relationships. Thousands upon thousands of specific musical streams, many quite different from one another, have exemplified the properties of Rhythm Changes.

In the previous post (in this series) I argued memes, the cultural parallel to the biological gene, are those physical properties of objects, events, and processes that allow different individuals to coordinate their participation in those things. In this view, memes are not physical objects, like genes, that spread through a population. Rather, memes are about sharability; they are physical properties that can easily be identified by human nervous systems and thus be the basis for shared (cultural) activity.

In that post I considered a very basic case, people making noise at regular intervals. In that case we have two memes, period (the interval between “hits”) and phase (the relationship between streams of hits by different individuals). Now I want to consider a considerably more complex case, the entity jazz musicians know as Rhythm Changes. This entity assumes that, for a given performance, period length and phase value are agreed upon. In fact it assumes a lot more. We’re dealing with a whole lot of memes here.

But I don’t want to get hung up in those details. I just want to characterize Rhythm Changes in a reasonable way and explain just why I insist that we regard Rhythm Changes as a structured collection of physical properties that can be ascribed to a stream of sound. While it would be nice to characterize Rhythm Changes using the language of acoustics, it’s not at all clear to me that we’ve got the necessary concepts. In any event, if we do, I don’t know them. Instead, I’ll couch my description in the schematic terms jazz musicians tend to use when talking about their craft; these terms are derived, in part, from descriptive and analytic concepts developed for European art music (i.e. classical music).

I’m going do this in two posts, the first will be confined to Rhythm Changes itself. The second will consider how Rhythm Changes came into being and how it functions in the popular music system. Continue reading “Wild Replicator’s Got Funky Rhythm, Part 1”

QHImp Qhallenge: Results on day 1

Earlier today we released an experiment on working memory in humans and chimps.  You can play the game here.

We’ve had responses from about 70 people, and we have some results.  Some are summarised on the live results page.

Astoundingly, people actually managed to get 9 numbers shown for only 210 ms!  Replicated Typo’s very own James Winters was one of those mavericks, but puts it down to luck.

There were some early leaders, but in the last few hours, the player known as ‘mjb’ has really kicked everybody’s ass and got to the top of all three leaderboards.  Who are you, magic human?  Let us know!

Continue reading “QHImp Qhallenge: Results on day 1”

The QHImp Qhallenge: Working memory in humans and Chimpanzees

Do you have a better memory than a chimp?  Tetsuro Matsuzawa demonstrated the amazing working memory abilities of Chimpanzees, but maybe humans can be just as good, with enough practice.  Justin Quillinan and I present the Quick-Hold Improvement Challenge (or QHImp Qhallenge).  Play our game and find out if you can beat a chimpanzee.

Play the game here.

You can see the results update live here.  Results so far are tantalizing: Replicated Typo’s very own James Winters has already reached the Ayumu benqhmark (9 numbers viewed for only 209 milliseconds)!

skip to Game instructions

Background

Tetsuro Matsuzawa presented his work on chimpanzees in a plenary talk at Evolang.  Matsuzawa covered several very interesting experiments and findings, including an experiment into the working memory of chimpanzees.  Ayumu is a chimpanzee who was trained to recognise Arabic numerals on a touch-screen and press them in sequence.  The most impressive aspect was that Ayumu could complete the task even when the numbers were only displayed for 210 milliseconds before being masked (the ‘eidetic memory task’ or ‘limited-hold’ memory task, Inoue & Matsuzawa, 2007):

You can see more videos of this at the Friends and Ai website.

Continue reading “The QHImp Qhallenge: Working memory in humans and Chimpanzees”

Evolang Coverage: Massimo Piattelli-Palmarini’s plenary talk

Post by Bodo Winter:

Massimo Piattelli-Palmarini’s talk at this Evolang gave an impressively confident and forceful argument for linguistic nativism. The basic tenets of the Chomskyan view of language evolution were reiterated with some old and some new arguments along the way. Piattelli-Palmarini (P.P.) claimed that (1) language is modular and autonomous from other cognitive systems, (2) syntax dominates other aspects of language such as semantics, and (3) that language has not arisen through natural selection because it is a non-adaptive trait. In line with Chomskyan syntactocentrism, syntax was argued to be the major evolutionary transition in the evolution of language.

Generally, it is a good thing to have strong arguments for a particular position because it spurs discussion and excites new research. However, P.P.’s arguments very much neglected or belittled major empirical advances in evolutionary linguistics and cognitive science. If this new evidence is taken into account, the picture that emerges is very different from what P.P. argued for.

Continue reading “Evolang Coverage: Massimo Piattelli-Palmarini’s plenary talk”

Comic suggests ‘putting down’ old physicists-turned-linguists

I seem to be the comic poster on this blog, but hey – Mark Liberman often quotes comics on Languagelog, and it’s before breakfast for me. So I feel ok with that.

(Update: I did beat Mark Liberman! By almost 5 hours! CF. http://languagelog.ldc.upenn.edu/nll/?p=3856)

Anyway, I was reading Saturday Morning Breakfast Cereal this morning, a comic that is occasionally quite good, and I came upon this gem. I wonder who exactly he is taking a jibe at with the physicist-turned-linguist mention. Any bets?



I’m glad he said first language, and not protolanguage. Proto-world isn’t the most likely thing we’re going to find – at best, we’ll be able to get half a dozen cognates, like Ruhlen did in 1994. Ruhlen is, of course, not a physicist, but a Greenbergian linguist, so he couldn’t have been the butt of the above joke. For that matter, I can’t be either – not because I am a linguist, but because I don’t believe there was one language, and I think it isn’t theoretically sound to stipulate that there was one language at any point in our history. My argument for this view (which I learned last week isn’t necessarily common) is that a) languages don’t exist outside of their host’s minds, anyway, so language needs to be redefined as a collaborative, shared signalling system b) this wouldn’t have occurred at any point in our history, excepting perhaps for the Adam and Eve time zones c) even then, we’d have different, contacting communities that would keep ‘language’ as such as a constantly changing system that would need to be defined most clearly in relation to the other contrasting systems, and d) even within the group, there would have been considerably idiolectic variation that would have, in my unfounded opinion, been much more rife in early language than today. I’m still working on backing that up theoretically, and hopefully one day with models.

Back to the comic, I hope you didn’t miss the reference to ‘tensors’ as well. Every time I see that word, I think of The Demolished Man, a truly fantastic science fiction book where a key point in the plot is that a man can block out psychics by repeating an annoying commercial meme – Tenser, said the tensor – in his head over and over again. Since we’re talking about science fiction, the comic above also reminds me of that one Star Trek episode where it is revealed that all Kaelon’s must commit mandatory suicide so that they don’t stress society by being elderly, sort of like Sarah Palin’s ‘death panels’.

Nothing in Language Makes Sense…

… Except in the Light of Biological and Cultural Evolution

Sean mentioned in one of his many Evolang posts that, based on de Boer’s talk, the real audience for researchers of cultural evolution should be biologists. Well, deciding that actions plus words can work far better together, I decided to get in contact with Jeremy Yoder of the excellent group blog, Nothing in Biology Makes Sense. The result: an introductory post on the biological and cultural evolution of language called Crossing Those Curious Parallels (after Darwin’s famous passage describing the similarities between linguistic and biological change). Most regular readers will be familiar with the content and argument as the article is a pastiche of earlier pieces I wrote on this blog, but there is a sprinkling of some original paragraphs here and there. So feel free to go over, leave a comment and help foster some cross-disciplinary discussions. Actually, on cross-disciplinary note: since physicists seem so keen to solve problems in linguistics, maybe we should lend them a hand and run a corpus analysis to discover that elusive mass of the Higgs boson.

 

 

Evolang coverage: More on linguistic replicators

Monica Tamariz presented a poster at Evolang (runner up for the best poster award) about linguistic replicators.  This is an alternative view to Andrew Smith’s talk and Bill Benzon’s post on the same subject.

Below I’ve copied out sections of Tamariz’s poster:

Continue reading “Evolang coverage: More on linguistic replicators”

Evolang Coverage: Honest signalling between plants and insects

Yashuiro Suzuki (from Nagoya University, co-authoring with Megumi Sakai and Kazuhiro Adachi) presents a model of the evolution of an honest signalling system between plants and insects.  While honest signalling systems have been studied before, this was the first I harve heard of one between species, and certainly between kingdoms.

The vast majority of animals communicate to some extent.  Many signalling systems used by animals use costly signals, the paradigm case bign the peacock’s tail (Zahavi & Zahavi, 1997).  Growing a long tail imposes a developmental and predatory cost and so only fit individuals can afford to grow long tails.  This makes it difficult to trick others into thinking that you are fitter than you actually are.

However, there are systems which use ‘cheap’ signals, the most often used example being badges of status in sparrows.  Sparrows have a patch of bright feathers on their chest.  A bigger patch signals a better fighter.  This is advantageous since they can avoid fights they would not win.  Yet, there appears to be no cost to growing the patch (although this is contested by some).  Zahavi & Zahavi suggest that ‘cheaters’ who do sport badges larger than their abilities are eventually punished when they get into fights with bigger birds.  Thus, the system remains honest.

Suzuki describes a system of communication between plants and insects.  Plants are in constant danger of bugs such as caterpillars.  However, some plants can emit a chemical that attracts small insects that will come and attack and eat the bugs.  The chemical is emitted when there are many bugs attacking.  However, there are plant mutants named ‘cry-wolf’ plants who emit the chemical even when there are very few bugs attacking it.  In this way, the cry-wolf plants have a small advantage over the normal plants.  However, the cry-wolf plants damage the stability of the signalling system.  The insects are attracted to the cry-wolf plants only to find a smaller meal than expected.  If this situation presists, the insect’s association between the chemical and food diminishes and they eventually stop coming.

Continue reading “Evolang Coverage: Honest signalling between plants and insects”

Evolang coverage: Network structure and the effect of L2 learners on language change

Evolang is over, but I have a backlog of posts to get out!

The idea that language change can be biased by the cognitive profiles of its learners has attracted a lot of interest (see Hanna’s post), and was a frequent topic of discussion at Evolang.  In the talk by James Winters and I, we urge a pluralistic approach involving statistical tests, models and experiments.  Here I describe some of the new studies relating to this presented at the conference.

Roland Mühlenbernd and Michael Franke discuss the network properties that characterise language contact.  They constructed an agent-based model where agents had to converge on a system of mapping two meanings onto two signals.  There were two evolutionary stable mappings:  Meaning 1 maps to word 1 and Meaning 2 maps to word 2, or meaning 1 maps to word 2 and meaning 2 maps to word 1.

Agents played communication games with others to settle on the mapping they use.  Mühlenbernd & Franke used two types of agent:  The rational agent which chooses the rationally best response and reinforcement learners based around a Polya-Urn model.  However, this factor didn’t make a significant difference in the results presented in this talk.

The main focus was the structure of the social network that determined which agents interacted.  Small world networks were generated using the Watts-Strogatz method which creates a variety of networks with certain degree and centrality features.  The social structure was held constant within each run, then the results over several runs were analysed.  Homogeneity always emerged, although the reinforcement learning maintained a higher number of ‘language regions’ (where connected agents used the same mappings) for longer.  These langauge regions tended to form in tightly connected regions of the network, not surprisingly.  Mühlenbernd & Franke looked at the properties of the langauge regions, including how early agents settled on a mapping (early vs late learners) and the strategies of agents on the border between dense communities (border agents).

Interestingly, there was a big overlap in late learners and border agents.  That is, people on the border between two communities tend to be late learners.  This offers an interesting take on the hypotheses linking second language learners and linguistic change.  Lupyan & Dale (2010) find a correlation between group size and morphological complexity.  They suggest that the cognitive profiles of L2 learners biases language change towards morphologically simpler languages.

This hypothesis is further supported by the work of Christian Bentz and Bodo Winter (not to be confused with James Winters, founder of this blog) also presented at this conference which shows that the ratio of L1 to L2 speakers of a language correlates with morphological features (number of cases, cast syncretism and case symmetry), while controlling for language family and geographic region.  However, as I suggested in my talk with James Winters, backing up a statistical correlation with another statistical correlation is not as powerful as running an experiment or a model.

Mühlenbernd & Franke’s model might provide some insight into this problem.  It shows that people who are the most likely to be in contact situations (on the borders of communities) are also more likely to be late learners.  If late learners in the model can equate to L2 learners, then this suggests a closer link than previously hypothesised between L2 learners and langauge change.  It would be interesting to think more about this dynamic.  However, Franke urged caution in interpreting the model in this way, since the concept of a ‘late learner’ is fairly abstract.

As a side note, Bart de Boer raised the intriguing idea you could use statistical analyses like Bentz and Winter’s to find exceptions to the rule.  Rather than them being problematic, perhaps by studying the causes of change in these exceptions, a clearer idea of the role of L2 speakers could emerge.

What’s clear is that there is an emerging body of work surrounding the linguistic niche hypothesis using statistical and modelling techniques.  Combined with Hannah Little’s experiment on this phenomenon, I’m wondering how long before we get a special issue on this subject.

Evolang Coverage: Simon Fisher: Molecular Windows into Speech and Language

In his clear and engaging plenary talk, Simon Fisher, who is director of the Department “Language & Genetics” at the Max-Planck-Institute for Psycholinguistics, the Netherlands, gave a summary of the current state of research on what molecular biology and genetics can contribute to the question of language evolution. Fisher was involved in the discovery of the (in)famous FOXP2 gene, which was found to be linked to hereditary language impairment in an English family. He has also done a lot of subsequent work on this gene, so naturally it was the also main focus of his talk.

But before he dealt with this area, he dispelled what he called the ‘abstract gene myth’. According to Fisher, it cannot be stressed enough that there is no direct relation between genes and behavior and that we have to “mind the gap”, as he put it. There is a long chain of interactions and relations that stand between genes one the one side, and speech and language on the other. DNA is related to the building of proteins, which is related to the development of cells. These in turn are related to neural circuits, which then relate to the human brain as whole, which then are related to speech and language.

So when we try to look at these complex net of relations, what we can say is that there is a subset of children which grow up in normal environments but still do not develop normal language skills. From a genetic perspective it is of interest that of these children, there are cases where these impairments cannot be explained by other transparent impairments like cerebral palsy, hearing loss, etc. Moreover, there are cases in which language disorders are heritable. This suggests that there are genetic factors that play a role in some of these impairments.

The most famous example of such a case of heritable language impairment is the English KE family, where affected members of the family are missing one copy of the FOXP2 gene. These family members exhibit impaired speech development. Specifically, they have difficulty in learning and producing sequences of complex oro-facial movements that underlie speech. However, they do show deficits in a wide range of language-related skills, including spoken and written language. It thus has to be emphasized that the missing FOXP2 gene seems to affect all aspects of linguistic development. It is also important that is not accompanied by general motor dyspraxia.

In general, non-verbal deficits are not central to the disorder. Affected individuals start out with a normal non-nonverbal IQ, but then don’t keep up with their peers, something that is very likely to be related to the fact that possessing non-impaired language opens the door for the enhancement of intelligence in various ways, something which people with only one FOXP2 gene cannot take advantage of to the same degree. In general, deficits in verbal cognition are much more severe and wide-ranging than other possible impairments. It is also important to note that after the FOXP2 gene was discovered in the KE family, researchers found a dozen of cases of a damaged FOXP2 gene that led to language-related problems.

FOXP2 is a so-called transcription factor, which means that it can activate and repress other genes. As Fisher points out, in a way FOXP2 functions as a kind of ‘genetic dimmer switch’ that tunes down the expression of other genes. In this context, it should become clear that FOXP2 is not “the gene for language.” Versions of FOXP2 are found in highly similar form in vertebrae species that lack speech and language. It therefore played very ancient roles in the brain of our common ancestor. Neither is FOXP2 exclusively expressed in the brain. It is also involved in the development of the lung, the intestines and the heart. However, work by Simon Fisher and his colleagues shows that FOXP2 is important for neural connectivity. Interestingly, mice with one damaged FOXP2 copy are absolutely normal in their normal baselines motor behavior. However, they have significant deficits in what Fisher called ‘voluntary motor learning.”

From an evolutionary perspective, it is relevant that there have been very little changes in the gene over the course of vertebrae evolution. However, there seem to have been more changes to the gene since our split from the chimpanzee lineage than there have been since the split from the mouse lineage. This means that when it comes to FOXP2, the protein of a chimpanzee is actually closer to a mouse than to a human.

Overall, what current knowledge about the molecular bases of language tells us is that these uniquely human capacities build on evolutionary ancient system. However, much more work is needed to understand the influence of FOXP2 on the molecular and cellular level and how these are related to the development of neural circuits, the brain, and finally our capacity for fully-formed complex human language.