Messages must be tuned to the target language: Some implications of crosslinguistic semantic diversity for neurolinguistic research on speech production

Abstract

Abstract There are nearly 6,500 languages in the world, and they vary greatly with regard to both lexical and grammatical semantics. Hence, an early stage of utterance planning involves thinking for speaking—i.e., shaping the thoughts to be expressed so they fit the idiosyncratic meanings of the symbolic units that happen to be available in the target language. This paper has three main sections that cover three distinct types of crosslinguistic semantic diversity. Each type is initially elaborated with examples, and then its implications for the neurobiology of speech production are considered. Type 1: Semantic field partitions. These are exemplified by huge crosslinguistic differences in many domains of meaning, including colors, body parts, household containers, events of cutting and breaking, and topological spatial relations. When such differences are viewed from the perspective of contemporary neurocognitive theories which assume that most concrete concepts are subserved by both modal (i.e., sensory, motor, and affective) and transmodal (i.e., integrative) cortical systems, they imply that speakers must access language-specific semantic structures at multiple levels of representation in the brain. Type 2: Semantic conflation classes. Some languages have whole sets of words that systematically encode two or more components of meaning. For instance, in the roughly 53 Athabaskan languages there are no generic verbs like give, carry, or throw; instead, there are entire sets of 9–13 verbs for these kinds of actions, with each set making the same distinctions between the types of objects that are given, carried, or thrown, such as animate objects, round objects, stick-like objects, flat objects, etc. This regular conflation of [action + object] in Athabaskan verb meanings predicts that speakers frequently co-activate both action-related and object-related cortical regions in a functionally integrated fashion. Type 3: Grammatically obligatory semantic categories. This kind of crosslinguistic variation involves not only the particular dimensions of experience that speakers are forced to track for grammatical purposes, but also the precise contrasts that they must make along those dimensions, with examples including systems of nominal classification, tense, and evidentiality. It is still not known exactly where or how the meanings of grammatically necessary closed-class morphemes are implemented in the brain, but it is quite clear that whatever the neural substrates of these meanings turn out to be, they are strongly influenced by crosslinguistic differences. In all, by focusing on three separate forms of crosslinguistic semantic diversity, this paper reinforces Levelt's (1989) point that messages must be tuned to the target language, and it also shows that this point continues to have significant consequences for neurolinguistic research on speech production.