Is recursion language-specific? Evidence of recursive mechanisms in the structure of intentional action
Introduction
In their seminal work Hauser, Chomsky, and Fitch (2002) argued that linguistic, syntactic recursion can be considered as the only constitutive feature of the faculty of language in the narrow sense. In other words, even though the faculty of language “broad sense” (FLB) also includes a phonological system based on the operations of the sensory-motor apparatus, and a conceptual-intentional system conferring meaning to syntactically structured representations, syntactic recursion is the only component of the faculty of language “narrow sense” (FLN).
More specifically, HCF’s hypothesis is that FLB – the set of syntactic, conceptual and phonological mechanisms constituting the faculty of language as a whole – includes mechanisms shared by language with other cognitive skills and shared by humans with other species. FLN, on the contrary, is composed only by “the core mechanisms of recursion as they appear in narrow syntax and the mappings to the interfaces”, which are “recently evolved”, “unique to our species” and “quite specific to FLN” (HCF, 2002, p. 1573). Recursion and the interfaces allowing interaction with the conceptual-intentional system (responsible for semantics and pragmatics, cf. Fitch, Hauser, & Chomsky, 2005, p. 182) and with the sensory-motor, phonological system might be the features differentiating human cognition from non-human animals and the faculty of language from the rest of our cognitive skills. Language essentially is, according to HCF, a system of sound-meaning connections endowed with a core syntactic recursive component enabling the construction of an infinite number of discrete expressions starting from a finite number of primitive elements.
The authors regard this hypothesis as providing a multidisciplinary conceptual framework, or research program (Brattico, 2010), able to analyze not only language but also, more generally, human creativity. The idea is that a recursive syntactic engine emerged in a cognitive economy that already included a phonological system and a conceptual system. The phonological and conceptual systems causally bond the syntactic system by way of imposing “legibility conditions”: syntactic structures, for example, must be able to express a conceptually valid meaning in a phonologically structurable format (Chomsky, 2000). But recursion allows the previously existing conceptual thought to go beyond the narrow scope of the sensory-motor horizon of the here and now through discrete infinity (Fitch, 2010, cf. Brattico, 2010).
HCF’s hypothesis has been criticized in different ways: there is evidence of the ability to discriminate recursive strings in non-human animals (Abe and Watanabe, 2011, Corballis, 2007, Gentner et al., 2006; cf. Bloomfield et al., 2011, van Heijningen et al., 2009) and there are non-syntactic (i.e., phonological, cf. Schreuder, Gilbers, & Quené, 2009) recursive structures in language. Relatively little work has been done, on the contrary, to test the claim that recursion is “quite specific to FLN” – that is, that recursion is language-specific.
In this work we will focus on this latter claim. We will argue that there are sensory-motor recursive structures in the domain of intentional action – that is, at the sensory-motor level that mediates our fundamental interactions with the environment. To this aim, we will first sketch the core concepts of HCF and current objections against it in order to clarify the target of the investigation: what is “recursion”? What are its central properties? What does it mean that they are “quite specific to FLN”? We will then introduce John R. Searle’s (1983) analysis of the intentionality of action, which characterizes intentions as logically and biologically primitive mental representations with a causally self-referential (and, therefore, self-embedding) logical structure which cannot be reduced to the logical structure of beliefs and desires (Searle, 1983, p. 36). On the grounds of this analysis, we will then argue that the specific features of recursion (self-embedding, long-distance dependence, identity preservation, discrete infinity) might be already present in the structure of the sensory-motor system. We will then review evidence from cognitive science and neuroscience to support the claim that motor-intentional recursion is language-independent. We will distinguish two explanatory hypotheses. According to the first hypothesis, linguistic recursion is embodied in sensory-motor processing: the available evidence allows us to hypothesize that HCF’s causal-evolutionary route might be taken the other way round, identifying in sensory-motor processing the roots of linguistic recursion. According to the second hypothesis, linguistic and motor-intentional recursions might be independent mechanisms, realized in distinct neural circuits, that can be (and in some cases are) double dissociated.
Finally, we will propose some reflections about the epistemic status of HCF as presenting an empirically falsifiable hypothesis, and on the possibility of testing recursion in different cognitive domains.
Section snippets
Recursion as the core of the faculty of language
Despite the pivotal role of recursion in HCF in explaining the evolution and uniqueness of language, both the original paper and the answer to the objections raised by Pinker and Jackendoff (2005, cf. Fitch et al., 2005) have very little to say about what the authors mean by “recursion” or about the reasons for regarding this mechanism as language-specific.
In HCF recursion is characterized just as “a core property of FLN” attributed to “narrow syntax”, that is “a computational mechanism […]
Recursion outside language: some potential counterexamples to HCF
Debate after HCF focused mainly on the issue of what is “recursion” and on whether recursion is human-specific and FLN-specific. By comparison, relatively little work has been done on the claim that recursion is language-specific.
Recursion and the logical structure of intentional action
Our hypothesis is that John R. Searle’s (1983) philosophical analysis of the intentionality of acting and perceiving can be extended to capture the presence of the crucial features of recursion (self-embedding, long-distance dependence, identity preservation, discrete infinity) in sensory-motor processing. Intentionality is, in philosophical jargon, a property of mental states in virtue of which some of them (such as beliefs, desires, hopes, fears, and intentions) are directed to, refer to, or
How many recursions? Disentangling the relationship between action and language
In the last paragraph we have discussed our hypothesis of recursive processes and structures in the domain of intentional action. Even assuming that this hypothesis is correct, a question remains: what are the relationships between linguistic recursion and recursion in the structure of intentional action? Adopting a Chomskyan perspective the answer seems reasonably predictable: since recursion is language-specific, then recursion in non-linguistic domains must be language-dependent. Therefore
Conclusion
In this paper we examined the issue of whether recursion is language-specific starting from HCF’s hypothesis that recursion is the only constitutive mechanism of the faculty of language.
The analysis of the structure of intentional action has led us to hypothesize the presence of recursive mechanisms at the level of motor intentionality. Intentions (both simple intentions-in-action and complex prior intentions) are satisfied if and only if the corresponding action is realized in a specific way
Acknowledgments
Research on the topics of this paper has been made as part of GV’s research projects on “Embodied, Embedded Mind and the Challenges of Subjectivity: Theoretical Perspectives and Historical-Philosophical Perspectives”, (Post-doctoral research funds, MIUR 2009, University of Palermo) and “The ecological and embodied bases of recursion” (PhD course in neuroscience, University of Turin). MA was supported by MIUR of Italy (FIRB 2012, RBFR12FOBD_001) and by the University of Turin (Ricerca
References (123)
- et al.
Recognition of mistakes and deceits in communicative interactions
Journal of Pragmatics
(2008) - et al.
Conversation and behavior games in the pragmatics of dialogue
Cognitive Science
(1993) - et al.
Hierarchical sequencing engages Broca’s area
NeuroImage
(2008) - et al.
Neural circuits of hierarchical visuo-spatial sequence processing
Brain Research
(2009) Finding structure in time
Cognitive Science
(1990)- et al.
The evolution of the language faculty: Clarifications and implications
Cognition
(2005) - et al.
The bodily self as power for action
Neuropsychologia
(2010) - et al.
At the root of embodied cognition: Cognitive science meets neuropsychology
Brain and Cognition
(2004) The role of gesture in communication and thinking
Trends in Cognitive Science
(1999)- et al.
How our hands help us learn
Trends in Cognitive Science
(2005)
The nature of the language faculty and its implications for evolution of language (Reply to Fitch, Hauser, and Chomsky)
Cognition
Broca’s area and the hierarchical organization of human behavior
Neuron
The faculty of language: What’s special about it?
Cognition
Stochastic approaches to understanding dissociations in inflectional morphology
Brain and Language
Does the intention to communicate affect action kinematics?
Consciousness and Cognition
Recursion in phonology
Lingua
Songbirds possess the spontaneous ability to discriminate syntactic rules
Nature Neuroscience
The As If in cognitive science, neuroscience and anthropology: A journey among robots, blacksmiths, and neurons
Theory and Psychology
Neuronal coding of serial order: Syntax of grooming in the neostriatum
Psychological Science
Correlations of subcortical CT lesions sites and aphasia profiles
Brain
A notional theory of syntactic categories
From monkey-like action recognition to human language: An evolutionary framework for neurolinguistics
Behavioral and Brain Sciences
How to do things with words
Linguistic communication and speech acts
Cognitive pragmatics
Intentional minds: A philosophical analysis of intention tested through fMRI experiments involving people with schizophrenia, people with autism, and healthy individuals
Frontiers in Human Neuroscience
The feeling of doing: Deconstructing the phenomenology of agency
Perception, action, and word meanings in the human brain: The case from action verbs
Annals of the New York Academy of Sciences
Cortex, striatum, and cerebellum: Control of serial order in a grooming sequence
Experimental Brain Research
What birds have to say about language
Nature Neuroscience
Recursion hypothesis considered as a research program in cognitive science
Minds and Machines
Freedom and action
Syntactic structures
The minimalist program
The architecture of language
Some simple evo devo theses: How true they might be for language?
A usage-based approach to recursion in sentence processing
Language Learning
Being there: Putting brain, body and world together again
Deficit in complex sequence processing after a virtual lesion of left BA45
PLoS ONE
Role of Broca’s area in motor sequence programming: A cTBS study
NeuroReport
Role of Broca’s area in implicit motor skill learning: Evidence from continuous theta-burst magnetic stimulation
Journal of Cognitive Neuroscience
Role of Brocas area in encoding sequential human actions: A virtual lesion study
NeuroReport
Recursion, language, and starlings
Cognitive Science
The recursive mind. The origins of human language, thought, and civilization
Freedom to act
Subcortical aphasia: Distinct profiles following left putaminal hemorrhage
Neurology
Mente, azione e linguaggio nel pensiero di John R. Searle
The role of Broca’s area in Broca’s aphasia
Journal of Clinical and Experimental Neuropsychology
The remembered present: A biological theory of consciousness
Intention processing in communication: A common brain network for language and gestures
Journal of Cognitive Neuroscience
Cited by (26)
The never-ending recursion
2017, Journal of Applied LogicCitation Excerpt :Under this approach, the use of recursion as it is understood in the first approach has been abandoned, and recursion has come to be understood as the ability to process recursive (i.e. self-embedded) structures, rather than as a part of some grammar formalism. According to Vicari and Adenzato [71, p. 173], among others, a self-embedded structure is one which is composed of a component (for instance, a constituent or a schema XP) that contains or embeds other component of the same kind (another constituent or schema XP) within itself: an X-within-X of the same kind. In this very sense, Moro refers to recursion as being a combinatory process which is summarized as follows: “a structure of a certain kind (a sentence, for example) that contains structures of the same kind (another sentence)” ([51, p. 62; see examples below]).1
Do we represent intentional action as recursively embedded? The answer must be empirical. A comment on Vicari and Adenzato (2014)
2015, Consciousness and CognitionCitation Excerpt :Elsewhere, we have offered our own perspective on this question, hearkening back to Lashley’s ideas that hierarchical organization is the key shared characteristic between action, music and language (Fitch & Martins, 2014). In a recent manuscript published in this journal, Vicari and Adenzato (Vicari & Adenzato, 2014), henceforth VA, analyze the plausibility of Hauser, Chomsky and Fitch’s (henceforth HCF) hypothesis (Hauser, Chomsky, & Fitch, 2002) that recursion is either domain-specific to language, or that recursion’s uses in other domains are parasitic upon linguistic recursion. VA aim to falsify this hypothesis by first identifying “the formal features of recursion” in intentional action, a non-linguistic domain, and then by showing that this domain is not grounded on language.
At the Core of Pragmatics: The Neural Substrates of Communicative Intentions
2015, Neurobiology of LanguagePredicting goals in action episodes attenuates BOLD response in inferior frontal and occipitotemporal cortex
2014, Behavioural Brain ResearchCitation Excerpt :Together, our findings support the view that IFG's role in action observation is the reconstruction of possible overarching long-term goals via retrieval and selection of semantic information [33] relevant for the integration of an action into an overarching action structure [34]. In a broader view, this interpretation corroborates recent notions of IFG as potential substrate for integration of perceptually distinct elements into hierarchically ordered structures [35–37]. Indeed, there are striking similarities of hierarchical organization in language and complex action sequences such as object manipulation ([36]; but see [38]).
Design of Computer Security Algorithm Based on Differential Evolution and Analysis of Data Structure Discreteness
2023, Proceedings - 2023 International Conference on Networking, Informatics and Computing, ICNETIC 2023When exceptions matter: bilinguals regulate their dominant language to exploit structural constraints in sentence production
2023, Language, Cognition and Neuroscience