LEXICAL ACCESS
المؤلف:
John Field
المصدر:
Psycholinguistics
الجزء والصفحة:
P151
2025-09-09
269
LEXICAL ACCESS
The retrieval of a lexical entry from the lexicon, containing stored information about a word’s form and its meaning.
Serial models of lexical access assume that we work through lexical entries in turn until we find a match for a word that we are hearing or reading. It is well established that frequent words are identified more quickly than infrequent ones. These models therefore propose that words are stored not just by similarity of form but also in order of frequency: words beginning with /k æ r/ would be accessed in the order CARRY– CARROT– CARRIAGE– CARRIER CARRION. This is the approach favoured, for example, by Forster’s (1979) search model.
Serial access makes few demands on the processor, but is slow in terms of time. The original assumption was that the human mind operated like early computers, which were restricted to serial operations. An alternative view is that words are accessed in parallel. A search might retrieve a large number of similar words and compare them simultaneously with the word on the page or in the speech signal. These words are sometimes referred to as candidates, and, in many parallel models are seen as competing with each other to be the one that is selected.
Competition between words is often represented in terms of activation. Prompted by a particular string of letters or sounds, we access a number of possible word matches. They are activated to different degrees– with the more likely ones (those that are most frequent and those that form the closest match to what is in the input) receiving more activation than the others. Activation level can change as the language user reads or hears more of the word– so some candidate words may have their activation boosted by late-arriving information while others may have their activation depressed.
A major issue for lexical access concerns the extent of the information that is used in order to achieve recognition. Is it solely perceptual information from the speech signal or page– or is other information brought to bear that is based on world knowledge or syntactic expectations? An autonomous view has it that information sources are kept separate in the interests of clear and rapid decision making; and that initial access is triggered on the basis of perceptual cues alone. Contextual and other information may become available at a later stage to check the outcome or to resolve ambiguity. An interactive view has it that all sources of information are available at the outset. In this case, context and syntax as well as the form of the input contribute to the activation of a particular candidate. A compromise adopted by Cohort Theory is that there is ‘bottom-up priority’ in spoken word recognition, with a word’s first 200 milliseconds or first syllable opening up a set of candidates on the basis of form. Activation is then modified in response to top-down contextual and syntactic considerations.
It is clear that context must be invoked at some point in order to deal with ambiguities created by homonyms or words that are polysemous (possessing multiple related senses). A much-quoted finding by Swinney (1979) suggests that all possible senses are automatically accessed before context is invoked to determine the appropriate one. Subjects briefly activated both senses of a word such as BUG despite a disambiguating context. There is evidence that the same mayeven happen with a form such as [wi:k] whose two senses are from different word classes.
An alternative view, supported by evidence, suggests that a great deal may depend upon the relative frequency of a word’s senses. If a sentence context favours the dominant sense, then that is likely to be the single meaning that is retrieved. If it favours a subordinate sense, all the senses are likely to be retrieved.
The effects of context on lexical access are distinct from the effects of spreading activation, where, after encountering the word FLOOR, a listener or reader is quicker than normal to identify associated words such as CEILING, DOOR or ROOM. This is a highly automatic effect which operates entirely at lexical level and reflects the way in which items are stored in the mental lexicon.
Discussion of lexical access tends to focus on word recognition by listeners and readers. But writers and speakers also need to retrieve words. Evidence from Slips of the Tongue and from aphasia indicates that they make use of both sense and form. If a speaker needs a word for a particular vegetable, they select candidates from a group of words associated by the concept ‘vegetable’. But they may also have a retrieval cue to the word’s form indicating that it begins with the stressed syllable /lk æ /. This might lead them at the same time to access a second group of words linked by their initial syllable. The double search would narrow the choice to CARROT and CABBAGE.
See also: Activation, Autonomous, Cohort Theory, Context, Inter active activation, Lexical recognition, Lexical storage, Logogen, Modularity2, Search model, TRACE
Further reading: Aitchison (2003); Forster (1990); Garnham (1985: Chap. 3); Reeves et al. (1998)
الاكثر قراءة في Linguistics fields
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