QT1

Comparatives approaches to language

Transverse Question

“Comparative Approaches to Language”

Proposers: Pascal Belin & Joël Fagot

Language being unique to the human cognitive system, one could logically consider that it can only be studied in the only species that features one: humans. Yet, a number of ILCB/BLRI researchers use animals including rodents, pet dogs, macaques and baboons to address the question of the cognitive and cerebral bases of language.

The Transverse Question we ask in this context is the following:

What can be learnt on language by studying animals without language?

A survey of relevant work performed at ILCB/BLRI suggests that studies follow two different approaches.

The first approach consists of using animals as an experimental model for studying cognitive or neural phenomena involved in human language. There the animal is not the object of study; it is used to better understand the cognitive or neural mechanisms involve in human language. For instance electrophysiological recordings in macaque auditory cortex can inform on the fine-grained neural mechanisms involved in human voice processing (Belin and colleagues).

The second approach follows an evolutionary perspective to understand why humans are the only species to have evolved a language and to describe the main stages of that evolution by looking for potential precursors of language in other animal species. For instance studying the baboon vocal productions allows testing predictions of models of language evolution that suggest a morphological inability to pronounce vowels as distinctive as humans as a main factor in lack of speech in monkeys (Boë et al., 2016).

In Porquerolles, we propose to discuss of the potentials and limitations of these two approaches, and their complementarity with studies involving human subjects. We find preferable at this stage to focus on comparative approaches involving animals, but this Transverse Question is naturally opened to other comparative approaches such as studies of preverbal infants that pose highly similar problems as animal studies.

We propose to structure the debate around the four following main topics:

  • Interest of animal models in studies of cognitive functions involved in language
  • Interest of animal models to study the cerebral bases “of language”
  • Interest of animal studies to understand language evolution
  • Theoretical implications of using animals to study human language

 

  • Interest of animal models in studies of cognitive functions involved in language

Animals can be used as experimental models for studying human language functions. For instance researchers use non-human primates to better understand the general principles of statistical regularity learning (Minier, Fagot & Rey, 2015) (involved in language acquisition in infants); to test the contribution of bottom-up processes to language dependent functions, such as orthographic processing (Grainger et al, 2012)

We propose to discuss the following questions:

  • What are the functional advantages of animal models for studying language?
  • For what questions is the animal model relevant in the context of studies of the cognitive bases of language?
  • What are the limits of animal models, such as for studying « higher-level » functions involved in language?

Relevant publications:

Grainger, J., Dufau, S, Montant, M, Ziegler, J.C & Fagot, J. (2012). Orthographic processing in baboons. Science, 336, 245-248.

Minier, L., Fagot, J., & Rey, A. (2015). The temporal dynamics of regularity extraction in non-human primates. Cognitive Science. Aug 25. doi : 10.1111/cogs.12279.

  • Interest of animal models to study the cerebral bases “of language”

Animals are also used by ILCB/BLRI researchers as experimental model for studying the cerebral bases of perceptual and cognitive abilities involved in language. Particularly macaques are used as experimental neuroscience model allowing by more invasive measurements that possible in human subjects (e.g., multi-electrode recordings, direct cortical stimulation) to obtain detailed electrophysiological and functional data on functions related to language (Perrodin et al, 2011; Plakke et al, 2015).

In this context we propose to discuss the following questions:

  • Which animal model to use to answer which question?
  • What potential links with studies of animal behaviour and cognition?
  • What is the functional and phylogenetic meaning of the cerebral homologies observed in animals and humans when addressing a function as integrated as language?

Relevant publications:

Belin P. Philos Trans R Soc Lond B Biol Sci. 2006 Dec 29;361(1476):2091-107. Voice processing in human and non-human primates.

Perrodin C, Kayser C, Logothetis NK, Petkov C. Curr Biol. 2011 Aug 23;21(16):1408-15. doi: 10.1016/j.cub.2011.07.028. Epub 2011 Aug 11. Voice cells in the primate temporal lobe.

Plakke B, Hwang J, Romanski LM. J Neurosci. 2015 Jul 1;35(26):9666-75. doi: 10.1523/JNEUROSCI.1218-15.2015. Inactivation of Primate Prefrontal Cortex Impairs Auditory and Audiovisual Working Memory.

  • Interest of animal studies to understand language evolution

The question of the origins of language and its evolution is at the core of many debates and investigations. Some researchers aim to identity THE cognitive (e.g., generativity, dendrophilia; Wang et al, 2015), social (cooperation; Moll & Tomasello 2007), cultural (cumulative culture; Dean et al 2014), genetic (foxP2 gene; Ackerman et al, 2014) or cerebral (network of connected areas; Rilling et al, 2008) factor at the origin of language evolution in humans. Others aim at describing precursors of language that can be found in animals (e.g., gestural origin of language, Meguerditchian et al, 2013; production of vowel-like sounds in monkeys; Fitch et al, 2016; Boë et al, 2017) or the evolution of cerebral structures (asymmetry of Broca’s area and the STS) or functions (voice sensitive areas) involved in human language.

We thus propose to discuss the following questions:

  • What approach to favor for better understanding language evolution?
  • What are the limits to the search for “precursors”
  • How informative are studies of the evolution of “domain-general” functions for understanding the emergence of language?
  • Interest of an ethological description of animal communicative systems for understanding language evolution?

Relevant publications:

Wang L, Uhrig L, Jarraya B, Dehaene S. Curr Biol. 2015 Aug 3;25(15):1966-74. doi: 10.1016/j.cub.2015.06.035. Epub 2015 Jul 23. Representation of numerical and sequential patterns in macaque and human brains.

Moll H, Tomasello M. Philos Trans R Soc Lond B Biol Sci. 2007 Apr 29;362(1480):639-48. Cooperation and human cognition: the Vygotskian intelligence hypothesis.

Dean LG, Vale GL, Laland KN, Flynn E, Kendal RL. Biol Rev Camb Philos Soc. 2014 May;89(2):284-301. doi: 10.1111/brv.12053. Epub 2013 Sep 2. Human cumulative culture: a comparative perspective.

Ackermann H, Hage SR, Ziegler W. Behav Brain Sci. 2014 Dec;37(6):529-46. doi: 10.1017/S0140525X13003099. Epub 2014 May 15. Review. Brain mechanisms of acoustic communication in humans and nonhuman primates: an evolutionary perspective.

Rilling JK, Glasser MF, Preuss TM, Ma X, Zhao T, Hu X, Behrens TE. Nat Neurosci. 2008 Apr;11(4):426-8. doi: 10.1038/nn2072. Epub 2008 Mar 23. The evolution of the arcuate fasciculus revealed with comparative DTI.

Meguerditchian A, Vauclair J, Hopkins WD. Dev Psychobiol. 2013 Sep;55(6):637-50. doi: 10.1002/dev.21150. Review. On the origins of human handedness and language: a comparative review of hand preferences for bimanual coordinated actions and gestural communication in nonhuman primates.

Fitch WT, de Boer B, Mathur N, Ghazanfar AA. Sci Adv. 2016 Dec 9;2(12):e1600723. eCollection 2016. Monkey vocal tracts are speech-ready.

Boë LJ, Berthommier F, Legou T, Captier G, Kemp C, Sawallis TR, Becker Y, Rey A, Fagot J. PLoS One. 2017 Jan 11;12(1):e0169321. doi: 10.1371/journal.pone.0169321. eCollection 2017. Evidence of a Vocalic Proto-System in the Baboon (Papio papio) Suggests Pre-Hominin Speech Precursors.

  • Theoretical implications of using animals to study human language

The comparative approach at the core of this Transverse Question may seem hardly compatible with a holistic conception of language viewed as a whole, which emerged at once during the phylogeny, and is uniquely present in humans It seems more compatible with a more gradual conception of language evolution, and a progressive emergence of critical building blocks of language during the phylogeny, some of these blocks being present in both humans and nonhuman animals while others are only present in humans (Fagot et al., in press). This kind of opposition, which was first proposed in a cognitive development framework where Skinner’s view (1957) was opposed to that of Chomsky (1959), warrants further considerations in this transverse question.

We thus propose to discuss the following questions:

  • What are the theoretical implications of the use of animals in language research?
  • What potential complementarities with other comparative approaches, particularly the study of preverbal infants

Relevant publications

Fagot, Malassis, Medam & Montant (in press). Comparing human and nonhuman animal performance on domain-general functions: towards a multiple bottleneck scenario of language evolution. In Origins of human language: continuities and splits with nonhuman primates (Boë, L.J., Fagot, J., Perrier, P. & Schwartz, J, eds.). Peterlang

Skinner, B. F. (1957). Verbal Behavior. New York: Appleton-Century-Crofts.Chomsky, N. (1959). A review of B.F. Skinner’s “Verbal Behavior.” Language, 35, 26–58.

Objectives of Transverse Question « Comparatives approaches to Language»

  • Generate a reflection on the benefits of the comparative approach involving animals for our understanding of human language.
  • Inform the community on the possibilities offered by ILCB/BLRI for studies involving animals.
  • Contribute to the emergence of novel synergies in ILCB/BLRI in particular amongst the different teams that use comparative approaches (work on development, modelisation etc.)

ILCB/BLRI members participating to the TQ « Comparative Approaches to Language»

Christelle Baunez, Pascal Belin, Clémentine Bodin, Olivier Coulon, Joël Fagot, Florence Gaunet, Elodie Giorla, Thierry Legou, Raphaelle Malassis, Tiphaine Medam, Adrien Meguerditchian, Marie Montant, Arnaud Rey (non-exhaustive list).

Porquerolles Debate organization proposal

We wish to organize the 90 min debate around the four above-mentioned questions: use of animals as model of (1) cognitive functions, (2) cerebral bases or (3) as a source of information on language evolution, and (4) of the theoretical implications of this work.

Each of these questions will make the object of a short intervention (about 5 minutes) to initiate the debate. An initial presentation of about 15 minutes will introduce in a more general way the objectives of this TQ.