Tag: children

Neural Language Networks at Birth

I haven’t had chance to read this paper, but it throws up some interesting discussion points relating to this blog. In particular, it relates to a hypothesis I put forward last year on Domain-General Regions and Domain-Specific Networks. Here is the abstract:

The ability to learn language is a human trait. In adults and children, brain imaging studies have shown that auditory language activates a bilateral frontotemporal network with a left hemispheric dominance. It is an open question whether these activations represent the complete neural basis for language present at birth. Here we demonstrate that in 2-d-old infants, the language-related neural substrate is fully active in both hemispheres with a preponderance in the right auditory cortex. Functional and structural connectivities within this neural network, however, are immature, with strong connectivities only between the two hemispheres, contrasting with the adult pattern of prevalent intrahemispheric connectivities. Thus, although the brain responds to spoken language already at birth, thereby providing a strong biological basis to acquire language, progressive maturation of intrahemispheric functional connectivity is yet to be established with language exposure as the brain develops.

Paper Link: http://www.pnas.org/content/108/38/16056.short?rss=1

 

Stephen Fry’s Planet Word

Stephen Fry has embarked on a series of documentaries about language, beginning with the evolution of language which he calls ‘the final frontier’ of human understanding.  The typical documentary hype is all here:  Stephen Pinker sits in a gigantic fish tank with bits of taxidermied brain lying around like sandwiches; Michael Tomasello appears to live in a tropical primate enclose; Fry conducts his studies from a medieval study complete with quills, a CGI tree of languages and a talking parrot.

Despite this, it was actually a coherent and comprehensive review of topics in the field: Language versus communication in animals, phisological constraints of language, creativity and the desire to share information, the pragmatic origins of language, FoxP2 and the poverty of the stimulus. Bilingualism is even added to this cannon of interesting ways to approach the origins of language, somewhat tempered by Fry’s question “wouldn’t it be better if everybody spoke Esperanto?”.

Mercifully, Fry seems to be actually interested rather than trying to build up the conspiracy plot format endemic in other science documentaries.  There are some odd diversions to a Klingon version of Hamlet, a trip to a German Christmas market and a slightly awkward re-enactment of a feral child case, but all in all the message is not objectionable: There is a graded difference between non-human and human communication, it’s partly genetic and partly cultural and languages continually change under pressures to be learned and to express new ideas.  There are also welcome additions of the original Wug test and, of course, Fry & Laurie’s seminal sketch about language.

Overall, I’d say it was the second best documentary the BBC have made about the origins of language.

Here’s a clip:

 

Also a clip of Fry talking about the series:

Compositionality and Bilingualism

Last week I put up a link to an online experiment.  Here’s the results! You can still do the experiment first, if you like, here.  Source code and raw results at the bottom.

Languages evolve over time under a pressure to be learned by a new generation.  Does learning two languages at once effect this pressure? My experiment says … maybe.

These pressures include ones for learnability (compression) and expressivity (able to express a large variety of meanings, Kirby, Cornish & Smith, 2008).  Bilingualism seems like an unlikely ability since learning an extra language leaves the speaker potentially no more expressive at a cost of an increase in the amount of effort required to learn it.  There is no pressure for one language structure (e.g. English) to adapt to another language (e.g. Mandarin) so that they can become optimally learnable and expressive as a single medium.  That is, there’s no reason to assume that expressivity and learnability pressures apply across languages (which are not being used by the same people).

Nevertheless, children display an aptitude and a willingness to learn and use multiple languages simultaneously, and at a similar rate to monolingual children.  Therefore, languages do seem to have adapted to be learnable simultaneously.  Does the compatibility of languages point to a strong innate property of language?  In contrast, it might point to underlying similarity in the structure of languages, brought about by universal principles of communication.

Continue reading “Compositionality and Bilingualism”

Cognitivism and the Critic 2: Symbol Processing

It has long been obvious to me that the so-called cognitive revolution is what happened when computation – both the idea and the digital technology – hit the human sciences. But I’ve seen little reflection of that in the literary cognitivism of the last decade and a half. And that, I fear, is a mistake.

Thus, when I set out to write a long programmatic essay, Literary Morphology: Nine Propositions in a Naturalist Theory of Form, I argued that we think of literary text as a computational form. I submitted the essay and found that both reviewers were puzzled about what I meant by computation. While publication was not conditioned on providing such satisfaction, I did make some efforts to satisfy them, though I’d be surprised if they were completely satisfied by those efforts.

That was a few years ago.

Ever since then I pondered the issue: how do I talk about computation to a literary audience? You see, some of my graduate training was in computational linguistics, so I find it natural to think about language processing as entailing computation. As literature is constituted by language it too must involve computation. But without some background in computational linguistics or artificial intelligence, I’m not sure the notion is much more than a buzzword that’s been trendy for the last few decades – and that’s an awful long time for being trendy.

I’ve already written one post specifically on this issue: Cognitivism for the Critic, in Four & a Parable, where I write abstracts of four texts which, taken together, give a good feel for the computational side of cognitive science. Here’s another crack at it, from a different angle: symbol processing.

Operations on Symbols

I take it that ordinary arithmetic is most people’s ‘default’ case for what computation is. Not only have we all learned it, it’s fundamental to our knowledge, like reading and writing. Whatever we know, think, or intuit about computation is built on our practical knowledge of arithmetic.

As far as I can tell, we think of arithmetic as being about numbers. Numbers are different from words. And they’re different from literary texts. And not merely different. Some of us – many of whom study literature professionally – have learned that numbers and literature are deeply and utterly different to the point of being fundamentally in opposition to one another. From that point of view the notion that literary texts be understood computationally is little short of blasphemy.

Not so. Not quite.

The question of just what numbers are – metaphysically, ontologically – is well beyond the scope of this post. But what they are in arithmetic, that’s simple; they’re symbols. Words too are symbols; and literary texts are constituted of words. In this sense, perhaps superficial, but nonetheless real, the reading of literary texts and making arithmetic calculations are the same thing, operations on symbols. Continue reading “Cognitivism and the Critic 2: Symbol Processing”

Cultural inheritance in studies of artifical grammar learning

Recently, I’ve been attending an artificial language learning research group and have discovered an interesting case of cultural inheritance.  Arthur Reber was one of the first researchers to look at the implicit learning of grammar.  Way back in 1967, he studied how adults (quaintly called ‘Ss’ in the original paper) learned an artificial grammar, created from a finite state automata.  Here is the grand-daddy of artificial language learning automata:

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The emergence of stable bilingualism in the lab: An experiment proposal

There is a huge amount of linguistic diversity in the world. Isolation and drift due to cultural evolution can explain much of this, but there are many cases where interacting groups use several languages. In fact, by some estimates, bilingualism is the norm for most societies. If one views language as a tool for communicating about objects and events, it seems strange that linguistic diversity should be maintained over time for two reasons. First, it seems more efficient, during language use, to have a one-to-one mapping between signals and meanings. In fact, mutual exclusivity is exhibited by young children and has been argued to be an innate bias and crucial to the evolution of a linguistic system. How or why do bilinguals over-ride this bias? Secondly, learning two language systems must be more difficult than learning one. What is the motivation for expending extra effort on learning an apparently redundant system?

Despite these obstacles, stable bilingualism exists in many parts of the world.   How might these arise and be maintained?  Continue reading “The emergence of stable bilingualism in the lab: An experiment proposal”

Emergence of linguistic diversity in the lab

There is a huge amount of linguistic diversity in the world. Isolation and drift due to cultural evolution can explain much of this, but there are many cases where linguistic diversity emerges and persists within groups of interacting individuals.  Previous research has identified the use of linguistic cues of identity as an important factor in the development of linguistic diversity (e.g. Nettle, 1999).  Gareth Roberts looks at this issue with an experimental paradigm.

This experiment was a game where individuals had to trade commodities in a series of rounds. At each round, individuals were paired up either with a team-mate or a competitor, though the speaker’s true identity was hidden.  Players were given random resources, but scored points based on how ‘balanced’ their resources were after trading (that is, you were punished for having much more meat than corn, for example).  A commodity given to another individual was worth twice as much to the receiver as to the donor.

Players could only interact through an ‘alien’ language via an instant-messaging system.  Prior to the game, individuals learned an artificial language which they were to use in these interactions. All participants were initially given the same starting language.  There were several conditions that manipulated the frequency with which you interacted with your team-mate and whether the task was competitive or co-operative.  In the co-operative condition, four players were considered as part of the same team and the task was to get a high a score as possible.  In the competitive condition the four players were split into two groups and the task was to score more than the other team.  In this condition, then, the main task was to identify whether your partner was a co-operator or a competitor.

The results showed that, if players interacted frequently enough with their team-mates and were in competition with another group, then linguistic diversity emerged.  Over the course of the game each team developed its own ‘variety’, and this was used as a marker of group identity. For example, in one game two forms of the word for ‘you’ arose.  Players in one team tended to use ‘lale’ while players in the other team tended to use ‘lele’, meaning that players could tell group membership from this variation.  Thus, linguistic variation arose due to the linguistic system evolving to encode the identity of the speakers.

The diversity seemed to arise both from drift and intentional change, both of which have been documented in the sociolinguistic literature.  Roberts suggests that linguistic markers make good social markers because they are costly to obtain (so difficult for free-riders to fake), salient and flexible enough to cope with changing group dynamics.  In the next post, I’ll be thinking about a similar experiment looking at how linguistic variation might arise in a co-operative scenario.

Roberts, G. (2010). An experimental study of social selection and frequency of interaction in linguistic diversity Interaction Studies, 11 (1), 138-159 DOI: 10.1075/is.11.1.06rob

Imitation and Social Cognition in Humans and Chimpanzees (II): Rational Imitation in Human Infants and Human-Raised Chimps

In my last post I wrote about two experiments on imitation in young children and chimpanzees by Lyons et al. (2005) and Horner & Whiten (2005).  Their results suggested that young children tend to copy both the ‘necessary’ and the ‘unnecessary’ parts of a demonstrator’s action who shows them how to get a reward out of a puzzle box, whereas chimps only copy the ones necessary to get the reward.

ResearchBlogging.orgOne important question raised by these experiments was whether these results can only be applied to wild chimpanzees or whether they also hold for enculturated, human-raised chimps. This is an important question because it is possible that chimpanzees raised in these kinds of richly interactive contexts show more sensitivity to human intentionality.

Buttelman et al. (2007) tested just that. They used the “rational imitation” paradigm, which features two conditions

a) the subjects are shown an action in which the specific manner of the action is not purposive and intentional but results from the demonstrator being occupied with something else. For example, he may be carrying something so that he has to use his foot to turn on a light (often called the Hands Occupied Condition).

b) the subjects are shown an action in which the demonstrator chooses a specific manner of doing something on purpose. For example he may have his hands free but still choosto turn on the light with his foot (Hands Free Condition).

taken from Call & Tomasello 2008

Continue reading “Imitation and Social Cognition in Humans and Chimpanzees (II): Rational Imitation in Human Infants and Human-Raised Chimps”

Imitation and Social Cognition in Humans and Chimpanzees (I): Imitation, Overimitation, and Conformity

ResearchBlogging.org

Imitation is often seen as one of the crucial foundations of culture because it is the basis of  social learning and social transmission. Only by imitating others and learning from them did human culture become cumulative, allowing humans to build and improve on the knowledge of previous generations. Thus, it may be one of the key cognitive specializations that sparked the success of the human evolutionary story:

Much of the success of our species rests on our ability to learn from others’ actions. From the simplest preverbal communication to the most complex adult expertise, a remarkable proportion of our abilities are learned by imitating those around us. Imitation is a critical part of what makes us cognitively human and generally constitutes a significant advantage over our primate relatives (Lyons et al. 2007: 19751).

Indeed, there have been some interesting experiments suggesting that the human capacity -and, above all, motivation – for imitation is an important characteristic that separates us from the other great apes.

In a series of intriguing experiments by Victoria Horner and Andrew Whiten from the University of St. Andrews in Scotland, and Derek Lyons and his colleagues from Yale University,  young wild-born chimpanzees and Children aged 3 to 4 were shown how to get a little toy turtle/ a reward out of a puzzle box. In the first condition of the experiment the puzzle box was transparent, whereas in the second condition the puzzle box was opaque.

And here’s the catch: both chimpanzees and children were not shown the ‘right’ or ‘simple’  solution to how to get the reward but one that was actually more complicated and involved unnecessary steps.

Continue reading “Imitation and Social Cognition in Humans and Chimpanzees (I): Imitation, Overimitation, and Conformity”