COMPETITION
A comparison between all possible lexical matches to a signal, in order to establish which most closely fits the available evidence. Most models of lexical access assume that visual or auditory evidence leads us to select a set of word candidates between which we have to choose. In, for example, Cohort Theory, hearing the initial sequence [Iksp] would lead a listener to retrieve from the lexicon a set of items which include EXPIRE, EXPECT, EXPLODE, EXPLAIN, EXPRESS etc. These would all receive activation; but, if the next sound proved to be [r], the activation for EXPRESS would be boosted to the point where it ‘fired’– i.e. was accepted as the only possible match for the evidence available. The activation of all others would decline. That said, some allowance has to be made for lack of clarity in the signal. This might mean that the activation of EXPLODE and EXPLAIN remained high until more of the signal had been processed and it became clear that the disambiguating phoneme was indeed [r] rather than [l].
Competition between words is not simply a question of how closely they match the signal. The activation of a word is boosted if it is of high frequency. Thus, EXPECT would start off at a higher level of activation than the less frequent EXPIRE– or alternatively would require a lower level of activation in order to achieve a match. Another criterion is the number of neighbours a word possesses. A reader is slower to recognise a written word such as HEAD which faces competition from a number of words (hear, heat, heap, heal) than a word such as HEED which (on a left-to-right basis) only competes with heel.
In some accounts of lexical access, the cues provided by context boost the activation of one or more competitors. Other accounts maintain that contextual information is only used to check the appropriacy of the winning candidate. A third view is that a minimal amount of the speech signal needs to be processed before contextual cues can be brought to bear.
Studies of lexical segmentation in listening have extended the notion of competition to any string of phonemes in the signal. Thus the sequence the waiter is represented as competing with the alternative interpretation the way to.
See also: Activation, Bottom-up processing, Interactive activation, Lexical access
Further reading: Aitchison (2003: Chaps 18–19); Altmann (1997: Chap. 6)
