EvoLang XI Plenary Talks

Sharon Thompson-Schil
Domain-generality and prefrontal cortex: Now what?

Beginning in 1997, and for over a decade following, I argued that a region of left prefrontal cortex long described as a language-specific module (i.e., Broca’s area) instead played a more general role in cognition, namely biasing competitive interactions to select among multiple, incompatible representations. Evidence for this position, both from my research group and from numerous other laboratories, comes from behavioral and physiological data from both healthy and brain-damaged populations. However, much remains unknown about the relation between this domain-general neural system and the seemingly domain-specific cognitive system we call language. How to proceed in answering that question? There are several somewhat distinct lines of research in which progress might be made in this regard. One tactic is to focus on properties of networks rather than the properties of nodes within networks; this is the approach the characterizes Fedorenko’s recent research (cf. Fedorenko & Thompson-Schill, 2014). A second tactic, which I will discuss, is to consider the relation of domain-general control systems and domain-specific language systems through a developmental lens: I will argue that the prolonged period of prefrontal cortex immaturity in children supports the human ability to acquire language, thereby suggesting a specific (and perhaps counterintuitive) connection between a domain-general and domain-specific functions. I will show evidence of the costs of control processes for some types of learning. And I, too, will speculate on how the language system may have emerged given what we know about brain evolution and the cognitive capacities of humans vs. non-human primates.

Evelina Fedorenko
Evolution of the human language system

The human language system evolved against the backdrop of other, evolutionarily older systems. How does the language system fit with the rest of our mind and brain? Does it rely on specialized mechanisms, or does it instead make use of machinery that we use to solve other complex tasks? Using data from brain imaging investigations and studies of patients with brain damage, I will argue that a set of regions in the adult human brain are specialized for language processing. These brain regions – residing in left frontal and temporal cortices – respond robustly during language comprehension and production, but show little or no response when we engage in arithmetic processing, hold information in working memory, inhibit irrelevant information, listen to music, observe gestures, or perceive meaningful non-linguistic representations. Furthermore, damage to the language system leaves non-linguistic cognitive abilities largely intact. However, the specificity that characterizes the language system does not necessarily imply that the relevant brain regions have evolved specifically for language. I speculate on how the language system may have emerged given what we know about brain evolution and the cognitive capacities of humans vs. non-human primates.

Vincent M. Janik
The evolution of complexity in marine mammal communication

The two most established model systems for the study of complexity in animal communication and comparisons to human language are nonhuman primates and song birds. However, both lack key features associated with complexity that are present in other animals. Bird song lacks semantics in the sense of utterances referring to objects in the external world. Primates show syntax and reference in their calls, but lack the ability to copy novel sounds. Several marine mammal species have all of these skills including vocal learning, syntax, reference and other advanced cognitive skills. Many seals and baleen whales produce song and may use learning when acquiring new song types. Grey seals and dolphins, however, are not known to sing, which makes their learning skills harder to interpret. In one of our playback studies, wild grey seal pups copied sound combinations in their environment when producing contact calls. Captive grey seals trained to copy sounds showed an interesting tendency to copy formant modulations but not modulations of the fundamental frequency. Bottlenose dolphins also use vocal learning for individual recognition making this a common theme. In laboratory and field studies, we found that dolphins use learned, individually specific signature whistles for individual recognition, negotiating reunions and, when copied by other dolphins, for addressing conspecifics. In developmental studies we have shown that signature whistles are formed early in life and that their modulation pattern does not relate to sex, age or size of the animal. Thus, new signature whistles types appear to be truly arbitrary signals and are introduced de novo into the communication repertoire of a group. Comparing pinnipeds and cetaceans overall, the most likely contexts for the evolution of vocal learning in marine mammals are sexual selection and individual or group recognition. Cognition research now needs to focus on the implications of this complexity on intentionality and representation of information in marine mammals.

Joan Bybee
Mechanisms of language change and language evolution

We know a great deal about how languages change over time and this can be used to understand early stages of evolution. Knowledge of language change can contribute to the understanding of evolution because there are a restricted number of types of change, and there is a broad directionality to change. Thus we can reasonably project from documented changes in the last few millennia back to changes at the very beginnings of language. What we know indicates that language change takes place gradually in language use by the repeated application of domain-general processes (Bybee 2003a, Bybee 2010). By explicating how one major type of change—the process of grammaticalization—occurs, we see evidence against the position that language change takes place in the language acquisition process.

The main factor spurring changes that comprise the process of grammaticalization is increase in frequency of use, that is, grammaticalization starts when two or more meaningful elements are used together frequently. Repeated use triggers the application of domain-general cognitive processes (Bybee 2003b). It is the iteration of these processes during use that accumulates to create grammatical forms and structures. The following changes occur in very small steps during usage events. No one process has been identified as the leader that triggers the others.

1. As a sequence is used repeatedly it becomes routinized and the sequence of phonological form becomes automated leading to reduction and overlap of articulatory gestures.

2. Repetition also leads to the weakening of semantic force by habituation (Haiman 1994).

3. A repeated sequence comes to be processed holistically; that is, the whole is associated with a whole situation, including the inferences made by the hearer (Traugott & Dasher 2002). This leads to the loss of compositionality, which in turn leads to use in new contexts, which leads to further increase in frequency and further application of these processes of change (Heine et al. 1991, Beckner & Bybee 2009).

As Heine & Kuteva 2007 have pointed out, as soon as our ancestors could use sounds symbolically and concatenate symbols, the grammaticalization process can begin. Grammaticalization researchers argue that this process has occurred over and over again throughout the evolution of the languages of the world. Thus the mechanisms underlying this process are among the prerequisites for modern language. Given these mechanisms, in combination with the communicative desiderata and patterns of interaction of humans, the actual paths of development in unrelated languages are often very similar. Cross-linguistic similarities (so-called ‘language universals’) are determined by the diachronic processes that create grammar, not by its learnability. The argument for this point is supported by the mechanisms outlined in 1 – 3, which can not be attributed to the acquisition process. Particular attention will be given to the points in (3): the importance of inference in communication and grammatical development, and the prevalence of loss of compositionality in language change.

References Beckner, C. & Bybee, J., 2009. A usage-based account of constituency and reanalysis. Language Learning, 59(Suppl.1), pp.29–48.
Bybee, J., 2003a. Cognitive processes in grammaticalization. In Michael Tomasello (ed.) The New Psychology of Language. Mahwah: Lawrence Erlbaum, pp. 145–167.
Bybee, J., 2010. Language, usage and cognition, Cambridge: Cambridge University Press.
Bybee, J., 2003b. Mechanisms of change in grammaticalization: the role of frequency. In Brian D. Joseph and Richard D. Janda (eds.) The handbook of historical linguistics. Oxford: Blackwell.
Haiman, J., 1994. Ritualization and the development of language. In William Pagliuca (ed.), Perspectives on grammaticalization. Amsterdam: John Benjamins, pp. 3–28.
Heine, B., Claudi, U. & Hünnemeyer, F., 1991. Grammaticalization: A conceptual framework, Chicago: University of Chicago Press.
Heine, B. & Kuteva, T., 2007. The genesis of grammar: a reconstruction, Oxford: Oxford University Press.
Traugott, E.C. & Dasher, R.B., 2002. Regularity in semantic change, Cambridge: Cambridge University Press.

Ljiljana Progovac
What Kind Of Grammar Did Early Humans (and Neanderthals) Command? A Linguistic Reconstruction

Here I pursue a linguistic reconstruction of the earliest stages of grammar, following a precise syntactic theory. This reconstruction arrives at the initial stages of grammar which are in consort with crosslinguistic variation attested in the expression of various syntactic phenomena, including transitivity and tense marking. Interestingly, in making an argument for the antiquity of language, Dediu & Levinson (2013, p. 11) express their hope “that some combinations of structural features will prove so conservative that they will allow deep reconstruction.” I propose that the earliest stages of syntax as reconstructed here provide just such a conservative platform from which all the subsequent variation could arise, and which could have been commanded also by our cousins and the common ancestor. The reconstruction is at the right level of granularity to exclude some hypotheses regarding the hominin timeline, and to support others. It leads to specific and testable hypotheses which can be explored in e.g. anthropology, neuroscience, and genetics.

See the full paper here

Richard Moore
Apes, Humans, and the Phylogenetic Emergence of Gricean Communication

It is often claimed that human but not ape communication is characterised by a Gricean intentional structure; and that it was the emergence of this structure after the split of the Pan-Homo clade that led to the development of language in humans but not apes. This view is supported by the assumption that Gricean communication requires cognitive abilities that apes lack but that human infants do not.

Against the standard view, I argue that there is no better evidence that young children possess the abilities required for Gricean communication than apes do. I argue that traditional accounts of Gricean communication likely intellectualise the sorts of cognition that it requires, and I develop a new account of the cognitive prerequisites of Gricean communication that is consistent with the possibility that both apes and humans are Gricean communicators. I also give a new account of why humans but not apes acquired language. I finish by suggesting that many of the cognitive abilities taken to be pre-requisites of Gricean communication may be a consequence of - and not a pre-requisite for - language development.

Debating primate pragmatics
Thom Scott-Phillips

I am delighted that the Evolang conference has chosen to have a plenary debate on pragmatics. The importance of pragmatics for language evolution has always been acknowledged, but until recently this acknowledgement has only occasionally extended much beyond lip-service. As such, a debate on whether non-human primates communicate in pragmatically similar ways to humans is a very welcome development.

It is generally agreed that much non-human communication is intentional. However, intentionality is not all there is to human communication. As Grice, Sperber & Wilson, and several others have pointed out, intentions are not just how humans communicate, they are also what we communicate. When I tell my audience that the next train is at 08.42, I express an intention that you believe that the next train is at 08.42. One of Grice's most fundamental insights was that this intention, X, is satisfied by your recognition of the fact that I have X. In this way, pragmatically competent communication is an exercise in social cognition. The technical term is ostensive communication.

In some recent publications I developed a framework with which to systematically analyse whether any particular group communicates in this way. I have used this framework to review findings in the developmental and comparative literatures, and have hence concluded that ostensive communication is probably uniquely human (Scott-Phillips, 2014, 2015a). I will review these arguments in my presentation. Richard Moore will argue for the opposite conclusion, namely that non-human primates do communicate in ways that are pragmatically similar to humans. Moore and I have recently debated some of these points in the pages of Animal Cognition, and I am sure that the Evolang discussion will advance this important conversation further (Scott-Phillips, 2015b, Moore, 2016, Scott-Phillips, 2016).

Moore, R. (2016). Meaning and ostension in great ape gestural communication. Animal Cognition, 19(1), 223-231.
Scott-Phillips, T. C. (2014). Speaking Our Minds. London: Palgrave Macmillan.
Scott-Phillips, T. C. (2015a). Non-human primate communication, pragmatics, and the origins of language. Current Anthropology, 56(1), 56-80.
Scott-Phillips, T. C. (2015b). Meaning in animal and human communication. Animal Cognition, 18(3), 801-805.
Scott-Phillips, T. C. (2016). Meaning in great ape communication: summarising the debate. Animal Cognition, 19(1), 233-238.

Erich Jarvis
Dissecting the molecular mechanisms of vocal learning and spoken language

Our long-term goal is to decipher the molecular mechanisms that construct, modify, and maintain neural circuits for vocal learning, a behavior critical for song in song-learning birds and spoken-language in humans. Remarkably, although all are distantly related, song-learning birds (songbirds, parrots, and hummingbirds) and humans have convergent forebrain pathways that control the acquisition and production of learned sounds. This convergent anatomy and behavior is associated with convergent changes in multiple genes that control neural connectivity and brain development, of which some when mutated are associated with speech deficits. Non-human primates and vocal non-learning birds have limited or no such forebrain vocal pathways, but yet possess forebrain pathways for learning and production of other motor behaviors. To explain these findings, I propose a motor theory of vocal learning origin, in which brain pathways for vocal learning evolved by brain pathway duplication of an ancestral motor learning pathway. Once a vocal learning circuit is established, it functions similarly as the adjacent motor learning circuits, but with some divergences in neural connectivity. To test this hypothesis, we are attempting to genetically engineer brain circuits for vocal learning, including in mice. These experiments should prove useful in elucidating basic mechanisms of speech and other complex behaviors, as well as their pathologies and repair.

Dean Falk
Evo-devo & the evolution of language

Among living primates, only humans evolved highly complex grammatical language. Once the neurological substrates for language emerged prehistorically, they likely formed the backbone for the subsequent evolution of other unique human abilities such as those involved in mathematics and music. As an alternative to the well-known hypotheses that “Man the Hunter” or, more recently, “Woman the Gatherer” were the primary movers of human evolution, this talk proposes a gender-neutral hypothesis that “Baby the Trendsetter” had a starring role via the emergence of three sequential “evo-devo” trends that were, ultimately, responsible for making our species cognitively distinct. In chronological order, these trends entailed (1) delayed locomotor development in infants that occurred millions of years ago in association with the origin of bipedalism, (2) infants seeking contact comfort from separated caregivers using body language and new ways of crying, and (3) acceleration of prenatal brain growth continuing through the first postnatal year in association with selection for motherese and, eventually, grammatical language. Delayed development made it impossible for infants to cling to their mothers without support and, thus, necessitated periodic physical separations of mothers and infants that are not experienced by any of the living monkeys or apes. The resulting trend for seeking contact comfort led to reciprocal and habitual vocal communication between mothers and infants that seeded the emergence of motherese. The third trend sparked additional evolution in hominin brain size and neurological organization, which contributed to the subsequent emergence of other higher-order cognitive abilities. As noted, an evolutionary focus on these three evo-devo trends in babies is inclusive with respect to sex/gender, rather than exclusively crediting just men or women as the prime movers of human evolution.