Chomsky derides purely statistical methods

This month sees MIT’s Brains, Minds, and Machines symposium. The opening panel discussion was moderated by Steven Pinker and called for a reboot in artificial intelligence. The panel consisted of Noam Chomsky, Marvin Minsky, Patrick Winston, Susan Carey, Emilio Bizzi, and Sidney Brenner. Most panelists called for a reboot of old style research methods in AI as opposed to the more narrow applications of AI seen today. An article on Technology review summarizes Chomsky’s contribution:

Chomsky derided researchers in machine learning who use purely statistical methods to produce behavior that mimics something in the world, but who don’t try to understand the meaning of that behavior. Chomsky compared such researchers to scientists who might study the dance made by a bee returning to the hive, and who could produce a statistically based simulation of such a dance without attempting to understand why the bee behaved that way. “That’s a notion of [scientific] success that’s very novel. I don’t know of anything like it in the history of science,” said Chomsky.

I wondered what people thought of this argument and how it relates to the computational and statistical models used to demonstrate language that are becoming so fashionable these days.

The Gestural Repertoire of the Wild Chimpanzee

In the past many studies have been done on the linguistic abilities of trained apes using artifical languages, but what about in the wild?

Catherine Hobaiter and Richard W. Byrne at the University of St. Andrews have carried out a new study looking at the intentional gestures of chimpanzees in the wild.

Whilst it is generall agreed that gestural communication in great apes as seen in the wild is intentional and elaborate and flexible the authors outline that there is still a lot of controversy with regards to interpretation of the system and how the apes acquire it. These questions are hard to untangle when studied in the captive settings of a zoo.

The study presents a systematic analysis of the gestures made by a population of chimpanzees in the wild. 4,397 cases of intentional gesture were recorded in Budongo, Uganda.

These recordings were used to identify 66 gesture types. These gestures were seen to differ between individuals and also between age classes. Regardless of these differences no gesture was used only by one individual. I worried when I first read this as sometime studies identify intentional gestures by using the criteria that the gestures were used in the same context a certain number of times, however, within this study the criteria for intention gesture was as follows:

Audience checking: The signaller shows signs of beingaware of the potential recipients and their state ofattention, e.g. turning to look at the recipient beforegesturing.

Response waiting: The signaler pauses at the end of thecommunication and maintains some visual contact.

Persistence: The production of further gestures, afterresponse waiting and in the absence of a response that in other cases is taken as satisfactory. (In certain circumstances, such persistence might be impossible, for example where an adult carries an infant away; these cases are marked as unable to persist, rather than nopersistence.)

The authors argue that these gestures are not acquired by ‘ontogenetic ritualization’, which is when actions which are performed to reach some goal become ritualised to the point that they can be anticipated from an intial gesture sequence. The authors carried out detailed analyses of two gestures to show that the action elements which the gestures were made up from did not match those of the original actions.

This lack of ontogenetic ritualisation may be down to these gestures being species-typical, or typical across all the great apes. Comparisons made with the recorded gestured of gorillas and orangutans show that chimpanzee overlap with at least 24 gestures which are recorded in all three species. Dr Hobaiter is cited as saying on the BBC story that:

“the gestures that apes use (and maybe some human gestures too) are derived from ancient shared ancestry of all the great ape species alive today.”

The gestures were also able to be used flexibly across contexts and were able to adjust to the audience, for example the chimps were shown giving silent gestures when their audience was attentive and used contact in their gestures when the audience was inattentive.

The paper includes extensive analysis of repertoire size across age groups, contexts each gesture type was used in as well as things like hand position and shape during gestures.

This is the first study of its type using a wild population of chimpanzees. It shows highly intentional use of a species-typical repertoire which seems surprising and certainly contributes evidence relating to the evolution of intentional communication.

Reference

Catherine Hobaiter and Richard W. Byrne (2011) The gestural repertoire of the wild chimpanzee. ANIMAL COGNITION. DOI: 10.1007/s10071-011-0409-2

 

Does Language Shape Thought? Different Manifestations of the Idea of Linguistic Relativity (I)

Does the language we speak influence or even shape the way we think? Last December, there was an interesting debate over at The Economist website with Lera Boroditsky defending the motion, and Language Log’s Mark Liberman against the motion (who IMO, both did a very good job).
The result of the online poll was quite clear: 78% agreed with the motion, while 22% disagreed.

There are, however, three main problems with this way of framing the question: First, it’s not really clear what ‘language’ really is, second, the same goes for “thought”, and third, there are many many ways of how “influencing” and “shaping” something can be conceptualized.
In this post I want to focus on the third problem and present a very useful classification system for hypotheses about linguistic relativity outlined in an article by Phillip Wolff and Kevin J. Holmes, which was published in the current issue Wiley Interdisciplinary Review: Cognitive Science.

Continue reading “Does Language Shape Thought? Different Manifestations of the Idea of Linguistic Relativity (I)”

Bayesian phylogenetic analysis of Japonic languages

Lee & Hasegawa (2011) use phylogenetic methods to trace the origins of Japonic languages and dialects.  Two hypotheses are considered:  First, the farming/language dispersal hypothesis posits that the main factor for the divergence of genetic and linguistic diversity was agricultural expansion.  Second, the diffusion/transformation hypothesis posits that cultural innovations such as farming can diffuse between societies, and so genetic and linguistic diversity should not be linked.  The estimate of the common linguistic ancestor was in accordance with the farming/language dispersal hypothesis, again suggesting that that linguistic diversity followed genetic diversity.

The study is notable in considering dialects as well as languages and using etymology dictionaries to reconstruct forms from Middle and Old Japanese.  The analysis is also done with their own reconstructions and another, unrelated set.  The technique is similar to that used by Russel Gray et al. (2009) to study Pacific settlement patterns.

Lee S, & Hasegawa T (2011). Bayesian phylogenetic analysis supports an agricultural origin of Japonic languages. Proceedings. Biological sciences / The Royal Society PMID: 21543358

Gray, R., Drummond, A., & Greenhill, S. (2009). Language Phylogenies Reveal Expansion Pulses and Pauses in Pacific Settlement Science, 323 (5913), 479-483 DOI: 10.1126/science.1166858

Cultural bottlenecks leads to Diversity in Birdsong

A new study has been conducted on dialect formation in birds:

Native North Island saddlebacks have developed such distinctive new songs in the past 50 years that it is not clear if birds on one island recognise what their neighbours are singing about, a Massey University study shows.

The phenomenon is an avian equivalent of the way human language develops regional accents and dialects as people migrate and settle in new locations, and provides fresh insights into how species evolve, says biology researcher Dr Kevin Parker, from the Institute of Natural Sciences at Albany.

I can’t find any published article but the press release is here.

 

Linguistic Structure: the Result of L2 Learners?

Wray and Grace (2007) propose that the structure of a language is dependent of the social structure of the population who speak it. Lupyan & Dale (2010) later showed this using statistical analysis. This has been discussed extensively on this blog before:

http://www.replicatedtypo.com/science/language-as-a-complex-adaptive-system/422/

http://www.replicatedtypo.com/uncategorized/memory-social-structure-and-language-why-siestas-affect-morphological-complexity/2382/

One of the proposed reasons for why large population size is thought to affect linguistic structure is that larger populations will have a larger ratio of second language (L2) speakers to first language (L1) speakers.

Languages within exoteric niches (large population and geographical spread with many language neighbors) have been shown to be more more morphologically isolating and, as a result, regular. This has proposed to be because of the biases of adult second language learners.

Esoteric languages are more irregular and morphologically complex and idiosyncratic. This is thought to be because of the biases of child learners.

There are studies which show that adult learners have a tendency to regularise languages but only under some circumstances. Hudson Kam & Newport (2009) show that adult learners will regularise unpredictable variability but only if it exists above a certain level of scatter and complexity.

As for the learning biases of children, Wray & Grace (2007) cite only one study which looked at children who were ‘native’ speakers of Esperanto (Bergen, 2001). Bergen (2001) found that the language that the children learnt displayed a loss of the accusative case and also displayed attrition in the tense system. Although Wray & Grace (2007) suggest that this explains patterns seen in esoteric communities, it may not be as straight forward as they suggest. The evidence suggests that esoteric conditions are going to display more morphological strategies in their languages which is the opposite to the biases the child learners of Esperanto are displaying. The children are rejecting morphological strategies in favour of attrition and word order.

I wanted to point out in this post that there is evidence to suggest that adult learners preserve irregularities and idiosyncrasies, while children learners regularize (suggesting the opposite to Wray & Grace).

Studies which have addressed these problems include Hudson Kam & Newport (2005) where adult learners of an artificial language preserved unpredictable variation and child learners of the same language regularized it. Hudson Kam & Newport (2009) show in a similar study that child learners of an artificial language will regularise unpredictable irregularity but, as mentioned above, adult learners will only do this where the irregularity passes a certain level of complexity.

However, some evidence does support Wray & Grace’s (2007) proposal about adult learners.  Smith & Wonnacott (2010) show that despite there being a tendency within individual adult learners to maintain the level of unpredicted variability within the language learning process, when put into a diffusion chain of adult learners the language regularises.  Smith & Wonnacott (2010) suggest that gradual processes such as this can explain the regularisation of languages over time. While this fits nicely with Wray & Grace’s (2007) theory there is still the problem that children are just as liable to regularise as adults if not more so.

 

This is just some relevant experiments which I thought lent something to the debate. I know there are other factors which have been proposed to have an effect on linguistic structure. I was just curious about people’s opinions on quite to what level L2 speakers have an effect.

Recall dependent on language?

A new study has been published in Current Biology which offers evidence to suggest that monkeys have the capacity for both recognition and recall of simple shapes.

The study showed that rhesus monkeys can recall shapes from memory. This was shown using an experiment which had the monkeys reproduce shapes on a computer touch screen. These findings suggest that the memory of humans and old world monkeys may be more similar than we previously suspected.

Recall is separate and special in comparison to recognition as it shows an ability to remember and visualise things which are not present in the moment. This is an ability which is implicated in skills such as planning and imagining. This is also thought to enhance things like navigation and social behavior. In the past it has thought that an ability to recall none present items is dependent on language. This has been suggested in the past by prominent linguists such as Charles Hockett who thought that the ability of displacement was facilitated by language and was a driving force behind its evolution.

Because of a lack of demand for recall in the lives of monkeys they will not use their recollection skills very often in the wild. In the press release, Benjamin Basile, who lead the study said:

“Maybe it’s often just easier to recognize the monkey, the food, or the landmark in front of you. What we do know is that they do seem to have the ability to recall information in the lab.”

Experiments with humans have shown that recall and recognition require different types of memory. This has been difficult to show with other primates as recall tests are difficult to devise for monkeys because they can’t draw or talk.

The experiment used five rhesus monkeys who were trained on a recall test in which they had to reproduce a simple figure on a touch screen from memory. The shapes were made up of large pixels or boxes on a screen. The monkeys were shown these shapes and then, after a delay, were presented with part of the shape in a different location. The monkeys had to replicate the rest of the shape by touching where the other pixels should be.

The monkeys remembered less in recall than in recognition tests which is the same case in humans. However, the recall performance deteriorated more slowly over time. The monkeys were also able to transfer their ability to recall shapes to novel shapes as they were shown to be able to recall shapes which weren’t used in training.

This ability has probably been present since our last common ancestor with old world monkeys some 30 million years ago and is probably not facilitated by language.

The study hypothesises that:

“Recollection and familiarity likely evolved because they solved functionally incompatible problems. For example, familiarity does not support detailed memory for context, but it is quick and resistant to distraction. Recollection is slower and more vulnerable to distraction but supports a more detailed and flexible use of memory. Familiarity might better allow rapid responses to foods and predators under distracting conditions, whereas recollection might be necessary to access knowledge of distant food locations or past social interactions for planning future behavior.”

References

Benjamin M. Basile, Robert R. Hampton. Monkeys Recall and Reproduce Simple Shapes from Memory. Current Biology, 28 April 2011

 

Chris Knight Arrested

Sorry, this isn’t really Language Evolution related besides Chris Knight’s obvious connection to the subject but thought it would be of interest to readers of the blog.

Last night Chris Knight and Camilla Power were arrested after planning to execute effigies of Prince William at Westminster Abbey. They were arrested ahead of the royal wedding today.

A professor of anthropology at the University of East London, Chris Knight along with his partner, Camilla Power, also a anthropology lecturer at UEL, were arrested outside their home in southeast London at around 6.15pm.

They were arrested on suspicion of conspiracy to cause public nuisance and breach of the peace.

Dr Knight was seen laid down on the pavement during the arrest in an attempt to stop officers moving him into a police van. But the police prevailed and they were held in a police station overnight.

This is not the first time Dr Knight has caused trouble. He was sacked from his position in 2009, following claims that he incited violence at the G20 protests.

THE add that the camera man who was at the scene of the arrest asked Dr Knight: “Can I get your house keys so I can feed the rabbit?”

I do hope that the rabbit is OK.

 

Bonobos Extract Meaning from Call Sequences

A new study appeared yesterday on PlosOne by Clay and Zuberbühler of St Andrews University on the communicative ability of bonobos.

Studies have been done in the past on language-trained bonobos such as Kanzi which have revealed some remarkable abilities that the species has with regards to representational and communication tasks.

These studies have focussed on trained apes which are reared in unnatural environments and extensively trained on artificial languages. This has produced some interesting results though research into bonobos’ natural communication has been thin on the ground until now.

Clay and Zuberbühler address this gap in the research with a playback study on the natural vocal communication of bonobos.

Bonobos are known to produce five distinct vocal signals when finding food, these have been demonstrated to be combined together to make longer call sequences. The study found that individual call types were poor indicators of food quality but that calls which displayed a concatenation of signals were much better indicators.

The study looked into whether receivers could extract meaning about the quality of food encountered by the caller by integrating across different call sequences.

They started by training four captive bonobos to find two types of foods in two different locations, those which are more preferred such as kiwis and those which are less preferred such as apples. The apes were recorded when finding these different food types and these recordings were used in the playback experiments. When the bonobos discovered their preferred food they emitted higher pitched long barks and short “peeps” and when they discovered the less-preferred food they made lower pitch “peep-yelps” and yelps. Sequences of the four calls which used different compositions were played back to bonobos who were familiar with those apes who had originally made the calls. All sequences contained the same number of calls. In response to these playbacks the study found that the apes devoted significantly more effort and time searching the space which was known to contain the food type indicated by the call sequence (shown in the graph below).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The bonobos were shown to attend not just to individual calls but to the entire sequences before they made inferences about the food encountered by a caller.

These results provide the first empirical evidence that bonobos are able to extract information about external events by attending to natural vocal sequences made by other bonobos. This study really highlights the importance of call combinations in their natural communication system.

References
Clay Z, Zuberbühler K, 2011 Bonobos Extract Meaning from Call Sequences. PLoS ONE 6(4): e18786. doi:10.1371/journal.pone.0018786

Neanderthal-human Hybrids

Paul Mason and Robert Short have an article out called Neanderthal-human hybrids (I wonder what that’s about?). Here is the abstract:

Evidence from studies of nuclear and mitochondrial DNA extracted from Neanderthal fossils and humans points to fascinating hypotheses concerning the types of interbreeding that occurred between these two species. Humans and Neanderthals share a small percentage of nuclear DNA. However, humans and Neanderthals do not possess the same mito­chondrial DNA. In mammals, mitochondrial DNA is exclusively maternally inherited. Taking into account an understanding of interspecific hybridity, the available data leads to the hypothesis that only male Neanderthals were able to mate with female humans. If Haldane’s Law applied to the progeny of Neanderthals and humans, then female hybrids would survive, but male hybrids would be absent, rare, or sterile. Interbreeding between male Neanderthals and female humans, as the only possible scenario, accounts for the presence of Neanderthal nuclear DNA, the scarcity of Neanderthal Y-linked genes, and the lack of mitochondrial DNA in modern human populations.

Paul Mason previously wrote about the topic over at Neuroanthroplogy, so I really don’t have much more to say on the topic, other than that I’ll get around to reading it over the next couple of days. I’m curious to see if the usual suspects in the genetics (Razib Khan), anthropological (Dienekes) and evolutionary (John Hawks) communities offer some food for thought on the topic.

For me, I’m actually more interested in Mason’s recent work on degeneracy… But that’s for a later post 😉