Tag Archives: Typology

LingLang Lunch (9/25/2012): Geoffrey K. Pullum (University of Edinburgh)

Psychology and the Claimed Infinitude of Sentences

Some linguists take it to be an established universal that human languages have infinitely many sentences. I explore their reasons for believing this. I argue that no evidence could support or refute the infinitude claim; no convincing argument has been advanced for its truth; no consequences would follow from it; it might not be universally true anyway; and there are no significant consequences for psychology if that is the case. I focus especially on the supposed link between the infinitude claim and “creative” human cognitive abilities such as being able to come up with new utterances that are appropriate to context.

LingLang Lunch (10/31/2012): Peter Graff (MIT)

Communicative Efficiency in the Lexicon

Some of the earliest as well as some of the most recent work on the role of communicative efficiency in natural language examined the patterning of word-length in the lexicon (Zipf 1949; Piantadosi et al. 2011). Frequent and predictable words tend to be phonologically shorter, while their infrequent and unpredictable counterparts tend to be longer, thus relativizing the articulatory effort invested by the speaker to the probability of her being misunderstood. In this talk, I show that it is not only word-length but also the actual phonological composition of words that facilitates the successful communication of intended messages. I show that the English lexicon is probabilistically organized such that the number of words that rely exclusively on a given contrast for distinctness follows from that contrast’s perceptibility (cf. Miller and Nicely 1955) beyond what is expected from the occurrence frequencies of the contrasting sounds. For example, there are more minimal pairs like pop:shop, which rely on the highly perceptible /p/:/ʃ/ opposition in the English lexicon than expected from the frequencies of /p/ and /ʃ/. Conversely, there are fewer minimal pairs like fought:thought, which rely on the confusable /f/:/θ/ contrast, than expected from the frequencies of /f/ and /θ/. Redundancy in the phonological code is thus not randomly distributed, but exists to supplement imperceptible distinctions between meaningful linguistic units as needed. I also show that English is not unique in this respect: across 60 languages, the perceptibility of a given contrast predicts the extent to which words in the lexicon rely on that contrast for distinctness. I argue that these patterns arise from the fact that speakers choose among words in ways that accommodate anticipated mistransmission (Mahowald et al. to appear) and present computational evidence in favor of the hypothesis that the global optimization of the phonological lexicon could have arisen from the aggregate effects of such word choices over the course of a language’s history (cf. Martin 2007).

LingLang Lunch (2/12/2014): Sohini Ramachandran (Brown University)

A geneticist’s approach to comparing global patterns of genetic and phonemic variation

A longstanding question in human evolution concerns the extent to which differences in language have been a barrier to gene flow among human populations. Human genetic studies often label populations based on the language spoken by sampled individuals, and interpret analyses of genetic variation based on linguistic relationships. However, no study has attempted a joint analysis of genetic and linguistic data. We have analyzed, separately and jointly, phonemes from 2082 languages and genetic data from 246 human populations worldwide. We find interesting parallels between the datasets, and one point of divergence is that languages with fewer neighbors can have large phoneme inventories while geographically isolated populations lose genetic diversity. I am particularly seeking advice and thoughts on how to best analyze these phoneme inventories in concert with the genetic analyses we are conducting.

Colloquium (9/16/2015): Edward Gibson (MIT)

Information theoretic approaches to language universals

Finding explanations for the observed variation in human languages is the primary goal of linguistics, and promises to shed light on the nature of human cognition. One particularly attractive set of explanations is functional in nature, holding that language universals are grounded in the known properties of human information processing. The idea is that grammars of languages have evolved so that language users can communicate using sentences that are relatively easy to produce and comprehend. In this talk, I summarize results from explorations into several linguistic domains, from an information-processing point of view.

First, we show that all the world’s languages that we can currently analyze minimize syntactic dependency lengths to some degree, as would be expected under information processing considerations. Next, we consider communication-based origins of lexicons and grammars of human languages. Chomsky has famously argued that this is a flawed hypothesis, because of the existence of such phenomena as ambiguity. Contrary to Chomsky, we show that ambiguity out of context is not only not a problem for an information-theoretic approach to language, it is a feature. Furthermore, word lengths are optimized on average according to predictability in context, as would be expected under and information theoretic analysis. Then we show that language comprehension appears to function as a noisy channel process, in line with communication theory. Given si, the intended sentence, and sp, the perceived sentence we propose that people maximize P(si | sp ), which is equivalent to maximizing the product of the prior P(si) and the likely noise processes P(si → sp ). We discuss how thinking of language as communication in this way can explain aspects of the origin of word order, most notably that most human languages are SOV with case-marking, or SVO without case-marking.

LingLang Lunch (9/27/2017): Richard Futrell (MIT)

Richard Futrell’s research focuses on explaining linguistic universals and variation in terms of facilitating efficient and robust communication. For more information, his website is here.
 

Memory and Locality in Natural Language

I explore the hypothesis that the universal properties of human languages can be explained in terms of efficient communication given fixed human information processing constraints. First, I show corpus evidence from 37 languages that word order in grammar and usage is shaped by working memory constraints in the form of dependency locality: a pressure for syntactically linked words to be close to one another in linear order. Next, I develop a new theory of human language processing cost, based on rational inference in a noisy channel, that unifies surprisal and memory effects and goes beyond dependency locality to a new principle of information locality: that words that predict each other should be close. I show corpus evidence for information locality. Finally, I show that the new processing model resolves a long-standing paradox in the psycholinguistic literature, structural forgetting, where the effects of memory appear to be language-dependent.

Colloquium (9/16/2015): Edward Gibson (MIT)

Edward Gibson’s “TedLab” investigates the relationship between culture and cognition; how people learn, represent and process language; and how all these affects the structure of human languages. For more information, his website is here.

Information theoretic approaches to language universals

Finding explanations for the observed variation in human languages is the primary goal of linguistics, and promises to shed light on the nature of human cognition. One particularly attractive set of explanations is functional in nature, holding that language universals are grounded in the known properties of human information processing. The idea is that grammars of languages have evolved so that language users can communicate using sentences that are relatively easy to produce and comprehend.  In this talk, I summarize results from explorations into several linguistic domains, from an information-processing point of view.

First, we show that all the world’s languages that we can currently analyze minimize syntactic dependency lengths to some degree, as would be expected under information processing considerations.  Next, we consider communication-based origins of lexicons and grammars of human languages.  Chomsky has famously argued that this is a flawed hypothesis, because of the existence of such phenomena as ambiguity.  Contrary to Chomsky, we show that ambiguity out of context is not only not a problem for an information-theoretic approach to language, it is a feature. Furthermore, word lengths are optimized on average according to predictability in context, as would be expected under and information theoretic analysis.  Then we show that language comprehension appears to function as a noisy channel process, in line with communication theory.  Given si, the intended sentence, and sp, the perceived sentence we propose that people maximize P(si | sp), which is equivalent to maximizing the product of the prior P(si) and the likely noise processes P(si → sp).  We discuss how thinking of language as communication in this way can explain aspects of the origin of word order, most notably that most human languages are SOV with case-marking, or SVO without case-marking.