Neurolinguistics is devoted to the study of the language-brain relationship, using the methodologies of neuropsychology and cognitive neuroscience to investigate how linguistic categories are grounded in the brain. Although the brain infrastructure for language is invariable across cultures, neural networks might operate differently depending on language-specific features. In this respect, neurolinguistic research on the Romance languages, mostly French, Italian, and Spanish, proved key to progress the field, especially with specific reference to how the neural infrastructure for language works in the case of more richly inflected systems than English. Among the most popular domains of investigation are agreement patterns, where studies on Spanish and Italian showed that agreement across features and domains (e.g., number or gender agreement) engages partially different neural substrates. Also, studies measuring the electrophysiological response suggested that agreement processing is a composite mechanism involving different temporal steps. Another domain is the noun-verb distinction, where studies on the Romance languages indicated that the brain is more sensitive to the greater morphosyntactic engagement of verbs compared with nouns rather than to the grammatical class distinction per se. Concerning language disorders, the Romance languages shed new light on inflectional errors in aphasic speakers and contributed to revise the notion of agrammatism, which is not simply omission of morphemes but might involve incorrect substitution from the inflectional paradigm. Also, research in the Romance domain showed variation in degree and pattern of reading impairments due to language-specific segmental and suprasegmental features. Despite these important contributions, the Romance family, with its multitude of languages and dialects and a richly documented diachronic evolution, is a still underutilized ‘treasure house’ for neurolinguistic research, with significant room for investigations exploring the brain signatures of language variation in time and space and refining the linking between linguistic categories and neurobiological primitives.
Valentina Bambini and Paolo Canal
Research in neurolinguistics examines how language is organized and processed in the human brain. The findings from neurolinguistic studies on language can inform our understanding of the basic ingredients of language and the operations they undergo. In the domain of the lexicon, a major debate concerns whether and to what extent the morpheme serves as a basic unit of linguistic representation, and in turn whether and under what circumstances the processing of morphologically complex words involves operations that identify, activate, and combine morpheme-level representations during lexical processing. Alternative models positing some role for morphemes argue that complex words are processed via morphological decomposition and composition in the general case (full-decomposition models), or only under certain circumstances (dual-route models), while other models do not posit a role for morphemes (non-morphological models), instead arguing that complex words are related to their constituents not via morphological identity, but either via associations among whole-word representations or via similarity in formal and/or semantic features. Two main approaches to investigating the role of morphemes from a neurolinguistic perspective are neuropsychology, in which complex word processing is typically investigated in cases of brain insult or neurodegenerative disease, and brain imaging, which makes it possible to examine the temporal dynamics and neuroanatomy of complex word processing as it occurs in the brain. Neurolinguistic studies on morphology have examined whether the processing of complex words involves brain mechanisms that rapidly segment the input into potential morpheme constituents, how and under what circumstances morpheme representations are accessed from the lexicon, and how morphemes are combined to form complex morphosyntactic and morpho-semantic representations. Findings from this literature broadly converge in suggesting a role for morphemes in complex word processing, although questions remain regarding the precise time course by which morphemes are activated, the extent to which morpheme access is constrained by semantic or form properties, as well as regarding the brain mechanisms by which morphemes are ultimately combined into complex representations.
D. H. Whalen
Phonetics is the branch of linguistics that deals with the physical realization of meaningful distinctions in spoken language. Phoneticians study the anatomy and physics of sound generation, acoustic properties of the sounds of the world’s languages, the features of the signal that listeners use to perceive the message, and the brain mechanisms involved in both production and perception. Therefore, phonetics connects most directly to phonology and psycholinguistics, but it also engages a range of disciplines that are not unique to linguistics, including acoustics, physiology, biomechanics, hearing, evolution, and many others. Early theorists assumed that phonetic implementation of phonological features was universal, but it has become clear that languages differ in their phonetic spaces for phonological elements, with systematic differences in acoustics and articulation. Such language-specific details place phonetics solidly in the domain of linguistics; any complete description of a language must include its specific phonetic realization patterns. The description of what phonetic realizations are possible in human language continues to expand as more languages are described; many of the under-documented languages are endangered, lending urgency to the phonetic study of the world’s languages. Phonetic analysis can consist of transcription, acoustic analysis, measurement of speech articulators, and perceptual tests, with recent advances in brain imaging adding detail at the level of neural control and processing. Because of its dual nature as a component of a linguistic system and a set of actions in the physical world, phonetics has connections to many other branches of linguistics, including not only phonology but syntax, semantics, sociolinguistics, and clinical linguistics as well. Speech perception has been shown to integrate information from both vision and tactile sensation, indicating an embodied system. Sign language, though primarily visual, has adopted the term “phonetics” to represent the realization component, highlighting the linguistic nature both of phonetics and of sign language. Such diversity offers many avenues for studying phonetics, but it presents challenges to forming a comprehensive account of any language’s phonetic system.