Jane Chandlee and Jeffrey Heinz
Computational phonology studies the nature of the computations necessary and sufficient for characterizing phonological knowledge. As a field it is informed by the theories of computation and phonology.
The computational nature of phonological knowledge is important because at a fundamental level it is about the psychological nature of memory as it pertains to phonological knowledge. Different types of phonological knowledge can be characterized as computational problems, and the solutions to these problems reveal their computational nature. In contrast to syntactic knowledge, there is clear evidence that phonological knowledge is computationally bounded to the so-called regular classes of sets and relations. These classes have multiple mathematical characterizations in terms of logic, automata, and algebra with significant implications for the nature of memory. In fact, there is evidence that phonological knowledge is bounded by particular subregular classes, with more restrictive logical, automata-theoretic, and algebraic characterizations, and thus by weaker models of memory.
Connectionism is an important theoretical framework for the study of human cognition and behavior. Also known as Parallel Distributed Processing (PDP) or Artificial Neural Networks (ANN), connectionism advocates that learning, representation, and processing of information in mind are parallel, distributed, and interactive in nature. It argues for the emergence of human cognition as the outcome of large networks of interactive processing units operating simultaneously. Inspired by findings from neural science and artificial intelligence, connectionism is a powerful computational tool, and it has had profound impact on many areas of research, including linguistics. Since the beginning of connectionism, many connectionist models have been developed to account for a wide range of important linguistic phenomena observed in monolingual research, such as speech perception, speech production, semantic representation, and early lexical development in children. Recently, the application of connectionism to bilingual research has also gathered momentum. Connectionist models are often precise in the specification of modeling parameters and flexible in the manipulation of relevant variables in the model to address relevant theoretical questions, therefore they can provide significant advantages in testing mechanisms underlying language processes.
Phonotactics is the study of restrictions on possible sound sequences in a language. In any language, some phonotactic constraints can be stated without reference to morphology, but many of the more nuanced phonotactic generalizations do make use of morphosyntactic and lexical information. At the most basic level, many languages mark edges of words in some phonological way. Different phonotactic constraints hold of sounds that belong to the same morpheme as opposed to sounds that are separated by a morpheme boundary. Different phonotactic constraints may apply to morphemes of different types (such as roots versus affixes). There are also correlations between phonotactic shapes and following certain morphosyntactic and phonological rules, which may correlate to syntactic category, declension class, or etymological origins.
Approaches to the interaction between phonotactics and morphology address two questions: (1) how to account for rules that are sensitive to morpheme boundaries and structure and (2) determining the status of phonotactic constraints associated with only some morphemes. Theories differ as to how much morphological information phonology is allowed to access. In some theories of phonology, any reference to the specific identities or subclasses of morphemes would exclude a rule from the domain of phonology proper. These rules are either part of the morphology or are not given the status of a rule at all. Other theories allow the phonological grammar to refer to detailed morphological and lexical information. Depending on the theory, phonotactic differences between morphemes may receive direct explanations or be seen as the residue of historical change and not something that constitutes grammatical knowledge in the speaker’s mind.
Sónia Frota and Marina Vigário
The syntax–phonology interface refers to the way syntax and phonology are interconnected. Although syntax and phonology constitute different language domains, it seems undisputed that they relate to each other in nontrivial ways. There are different theories about the syntax–phonology interface. They differ in how far each domain is seen as relevant to generalizations in the other domain, and in the types of information from each domain that are available to the other.
Some theories see the interface as unlimited in the direction and types of syntax–phonology connections, with syntax impacting on phonology and phonology impacting on syntax. Other theories constrain mutual interaction to a set of specific syntactic phenomena (i.e., discourse-related) that may be influenced by a limited set of phonological phenomena (namely, heaviness and rhythm). In most theories, there is an asymmetrical relationship: specific types of syntactic information are available to phonology, whereas syntax is phonology-free.
The role that syntax plays in phonology, as well as the types of syntactic information that are relevant to phonology, is also a matter of debate. At one extreme, Direct Reference Theories claim that phonological phenomena, such as external sandhi processes, refer directly to syntactic information. However, approaches arguing for a direct influence of syntax differ on the types of syntactic information needed to account for phonological phenomena, from syntactic heads and structural configurations (like c-command and government) to feature checking relationships and phase units. The precise syntactic information that is relevant to phonology may depend on (the particular version of) the theory of syntax assumed to account for syntax–phonology mapping. At the other extreme, Prosodic Hierarchy Theories propose that syntactic and phonological representations are fundamentally distinct and that the output of the syntax–phonology interface is prosodic structure. Under this view, phonological phenomena refer to the phonological domains defined in prosodic structure. The structure of phonological domains is built from the interaction of a limited set of syntactic information with phonological principles related to constituent size, weight, and eurhythmic effects, among others. The kind of syntactic information used in the computation of prosodic structure distinguishes between different Prosodic Hierarchy Theories: the relation-based approach makes reference to notions like head-complement, modifier-head relations, and syntactic branching, while the end-based approach focuses on edges of syntactic heads and maximal projections. Common to both approaches is the distinction between lexical and functional categories, with the latter being invisible to the syntax–phonology mapping. Besides accounting for external sandhi phenomena, prosodic structure interacts with other phonological representations, such as metrical structure and intonational structure.
As shown by the theoretical diversity, the study of the syntax–phonology interface raises many fundamental questions. A systematic comparison among proposals with reference to empirical evidence is lacking. In addition, findings from language acquisition and development and language processing constitute novel sources of evidence that need to be taken into account. The syntax–phonology interface thus remains a challenging research field in the years to come.
Language is a system that maps meanings to forms, but the mapping is not always one-to-one. Variation means that one meaning corresponds to multiple forms, for example faster ~ more fast. The choice is not uniquely determined by the rules of the language, but is made by the individual at the time of performance (speaking, writing). Such choices abound in human language. They are usually not just a matter of free will, but involve preferences that depend on the context, including the phonological context. Phonological variation is a situation where the choice among expressions is phonologically conditioned, sometimes statistically, sometimes categorically. In this overview, we take a look at three studies of variable vowel harmony in three languages (Finnish, Hungarian, and Tommo So) formulated in three frameworks (Partial Order Optimality Theory, Stochastic Optimality Theory, and Maximum Entropy Grammar). For example, both Finnish and Hungarian have Backness Harmony: vowels must be all [+back] or all [−back] within a single word, with the exception of neutral vowels that are compatible with either. Surprisingly, some stems allow both [+back] and [−back] suffixes in free variation, for example, analyysi-na ~ analyysi-nä ‘analysis-