Examination of naturally occurring cases in which a person reports that a word is on the tip of his or her tongue has led several theorists to propose that an important role is played by blocking words whose intrusions hinder access to the correct targets. As yet, however, the blocking mechanism appears to have received little direct investigation experimentally. It was studied here by adapting the classic method of Brown and McNeill in which a person is presented with a definition (...) of a rare word and uses it to attempt to generate that target word. The adaptation that was made was to append a potential blocking word to the presentation of each definition. The potential blocking words were either phonologically related to the target or not, either semantically related to the target or not, and either rare or not. Only the first of these factors exerted a significant effect—more cases of tip of the tongue were experienced when the potential blocking word was phonologically related to the target than when it was not. This result suggests that the recall of a word on the basis of its meaning may proceed via an intermediate stage characterised by partial retrieval of its phonology. (shrink)

Preparing words in speech production is normally a fast and accurate process. We generate them two or three per second in fluent conversation; and overtly naming a clear picture of an object can easily be initiated within 600 msec after picture onset. The underlying process, however, is exceedingly complex. The theory reviewed in this target article analyzes this process as staged and feedforward. After a first stage of conceptual preparation, word generation proceeds through lexical selection, morphological and phonological encoding, phonetic (...) encoding, and articulation itself. In addition, the speaker exerts some degree of output control, by monitoring of self-produced internal and overt speech. The core of the theory, ranging from lexical selection to the initiation of phonetic encoding, is captured in a computational model, called WEAVER++. Both the theory and the computational model have been developed in interaction with reaction time experiments, particularly in picture naming or related word production paradigms, with the aim of accounting for the real-time processing in normal word production. A comprehensive review of theory, model, and experiments is presented. The model can handle some of the main observations in the domain of speech errors (the major empirical domain for most other theories of lexical access), and the theory opens new ways of approaching the cerebral organization of speech production by way of high-temporal-resolution imaging. (shrink)