Language production

Language production is the production of spoken or written language. In psycholinguistics, it describes all of the stages between having a concept, and translating that concept into linguistic form. These stages have been described in two types of processing models: the lexical access models and the serial models. In computational linguistics/natural language processing and artificial intelligence, the term natural language generation (NLG) is more common, and those models may or may not be psychologically motivated. Through these models, psycholinguists can look into how speech is produced in different ways, such as when the speaker is bilingual and when the speaker has a speech-related disorder like aphasia. Psycholinguists learn more about these models and different kinds of speech by using language production research methods that include collecting speech errors and elicited production tasks.

Stages of production

Language production consists of several interdependent processes which transform a nonlinguistic message into a spoken, signed, or written linguistic signal. Though the following steps proceed in this approximate order, there is plenty of interaction and communication between them. The process of message planning is an active area of psycholinguistic research, but researchers have found that it is an ongoing process throughout language production. Research suggests that messages are planned in roughly the same order that they are in an utterance. But, there is also evidence that suggests the verbs that give case may be planned earlier than objects, even when the object is said first. After identifying a message, or part of a message, to be linguistically encoded, a speaker must select the individual words—also known as lexical items—to represent that message. This process is called lexical selection. The words are selected based on their meaning, which in linguistics is called semantic information. Lexical selection activates the word's lemma, which contains both semantic and grammatical information about the word.

This grammatical information is then used in the next step of language production, grammatical encoding. Critical grammatical information includes characteristics such as the word's syntactic category (noun, verb, etc.), what objects it takes, and grammatical gender if it is present in the language. Using some of these characteristics as well as information about the thematic roles of each word in the intended message, each word is then assigned the grammatical and thematic role it will have in the sentence. Function morphemes, like the plural /s/ or the past tense /ɪd/, are added in this stage as well. After an utterance, or part of one, has been formed, it then goes through phonological encoding. In this stage of language production, the mental representation of the words to be spoken is transformed into a sequence of speech sounds to be pronounced. The speech sounds are assembled in the order they are to be produced.

The basic loop occurring in the creation of language consists of the following stages:

• Intended message
• Encode message into linguistic form
• Encode linguistic form into speech motor system
• Sound goes from speaker's mouth to hearer's ear auditory system
• Speech is decoded into linguistic form
• Linguistic form is decoded into meaning

According to the lexical access model (see section below), in terms of lexical access, two different stages of cognition are employed; thus, this concept is known as the two-stage theory of lexical access. The first stage, lexical selection provides information about lexical items required to construct the functional level representation. These items are retrieved according to their specific semantic and syntactic properties, but phonological forms are not yet made available at this stage. The second stage, retrieval of wordforms, provides information required for building the positional level representation.

Models of production

Serial model

A serial model of language production divides the process into several stages. For example, there may be one stage for determining pronunciation and a stage for determining lexical content. The serial model does not allow overlap of these stages, so they may only be completed one at a time.

Connectionist model

Several researchers have proposed a connectionist model, one notable example being Dell . According to his connectionist model, there are four layers of processing and understanding: semantic, syntactic, morphological, and phonological. These work in parallel and in series, with activation at each level. Interference and misactivation can occur at any of these stages. Production begins with concepts, and continues down from there. One might start with the concept of a cat: a four-legged, furry, domesticated mammal with whiskers, etc. This conceptual set would attempt to find the corresponding word {cat}. This selected word would then select morphological and phonological data /k / at/. The distinction of this model is that, during this process, other elements would also be primed ({rat} might be somewhat primed, for example), as they are physically similar, and so can cause conceptual interference. Errors might also occur at the phoneme level, as many words are phonetically similar, e.g. mat. Substitutions of similar consonant sounds are more likely to occur, e.g. between plosive stop consonants such as d, p and b. Lower primed words are less likely to be chosen, but interference is thought to occur in cases of early selection, where the level of activation of the target and interference words is at the same level.

Lexical access model

This model states that the sentence is made by a sequence of processes generating differing levels of representations. For instance, the functional level representation is made on the a preverbal representation, which is essentially what the speaker seeks to express. This level is responsible for encoding the meanings of lexical items and the way that grammar forms relationships between them. Next, the positional level representation is built, which functions to encode the phonological forms of words and the order they are found in sentence structures. Lexical access, according to this model, is a process that encompasses two serially ordered and independent stages.

Additional aspects of production

Fluency

Main article: Fluency

Fluency can be defined in part by prosody, which is shown graphically by a smooth intonation contour, and by a number of other elements: control of speech rate, relative timing of stressed and unstressed syllables, changes in amplitude, and changes in fundamental frequency.

Multilingualism

Whether or not a speaker is fluent in only one language, the process for producing language remains the same. However, bilinguals speaking two languages within a conversation access both languages at the same time. The three most commonly discussed models for multilingual language access are the Bilingual Interactive Activation model, the Revised Hierarchical Model, and the Language Mode model:

• Bilingual Interactive Activation Plus, updated from a model made by Dijkstra and Van Heuven, uses solely bottom-up processing to facilitate bilingual language access.
• Revised Hierarchical Model, developed by Kroll and Stewart, is a model suggesting that bilingual brains store meanings in a common place, word-forms are separated by language.
• Language Mode Model, made by Grosjean, uses two assumptions to map bilingual language production in a modular way. These assumptions are that a base language is activated in conversation, and that the speaker's other language is activated to relative degrees depending on context. De Bot describes it as overly simple for the complexity of the process, but suggests it has room for expansion.

Speakers fluent in multiple languages can inhibit access to one of their languages, but this suppression can only be done once the speaker is at a certain level of proficiency in that language. A speaker can decide to inhibit a language based on non-linguistic cues in their conversation, such as a speaker of both English and French conversing with people who only speak English. When especially proficient multilingual speakers communicate, they can participate in code-switching. Code-switching has been shown to indicate bilingual proficiency in a speaker, though it had previously been seen as a sign of poor language ability.

Research into production

There are three main types of research into language production: speech error collection, picture-naming, and elicited production. Speech error collection focuses on using the analysis of speech errors made in naturally produced speech. On the other hand, elicited production focuses on elicited speech and is conducted in a lab. Also conducted in a lab, picture-naming focuses on reaction-time data from picture-naming latencies. Although originally disparate, these three methodologies are generally looking at the same underlying processes of speech production.

Speech errors

Main article: Speech error

Analysis of speech errors has found that not all are random, but rather systematic and fall into several categories. Although speech production is very fast, (2 words per second) the error rate of the utterances are relatively rare (less than 1/1000) and those errors are categorized as follows:

• Anticipation: The word is in the speaker's mind and ready to be spoken, but the speaker says it too quickly. This could be because the speaker is planning and holding words in their mind.
• Perseveration: The word retains characteristics of a word said previously in a sentence:

Taddle Tennis instead of Paddle Tennis

• Blending: More than one word is being considered and the two intended items "blend" into a single item, perhaps implying the speaker is waffling between a few word options.

The child is looking to be spaddled instead of spanked or paddled

• Addition: adding of linguistics material, resulting in words like implossible.
• Substitution: a whole word of related meaning is replacing another. These errors can be far apart from another, or target words, and are generally grammatically consistent and accurate.

at low speed it's too light (instead of heavy)

• Malapropism: a lay term referring to the incorrect substitution of words. It is a reference to a character Mrs Malaprop from Sheridan's The Rivals.

Makes no delusions to the past.

The pineapple of perfection.

I have interceded another letter from the fellow.

• Spoonerism: switching the letters from words. For example, the phrase slips of the tongue could become tips of the slung.

Picture-naming

Picture-naming tasks ask participants to look at pictures and name them in a certain way. By looking at the time course for the responses in these tasks, psycholinguists can learn more about the planning involved in specific phrases. These types of tasks can be particularly helpful for investigating cross-linguistic language production and planning processes.

Elicited Production

Elicited production tasks ask participants to respond to questions or prompts in a particular way. One of the more common types of elicited production tasks is the sentence completion task. These tasks give the participants the beginning of a target sentence, which the participants are then asked to complete. Analyzing these completions allow psycholinguistics to investigate errors that might be difficult to elicit otherwise.

See also

• Developmental verbal dyspraxia
• FOXP2
• Langue and parole
• Speech-language pathology

Further reading

• Carroll, David W. (2008). Psychology of language. Australia ; Belmont, CA: Thomson/Wadsworth. ISBN 978-0-495-09969-7. OCLC 759885789.