Theoretical Approaches to Speech Production :: Spreading Activation Theory SAT

Theoretical Approaches to lyric Production on that point argon two main theories of Speech production, dispersion Activation Theory - SAT (Dell, 1986 Dell & OSeaghdha, 1991) and Word- Form encode by Activation and Verification WEAVER++ (Levelt et al., 1989 1999).The SAT conjecture was devised by Dell (1986) then revised by Dell & OSeaghda (1991). The theory works on a 4 take aim connectionist model correspond and dynamic.The Semantic take aim is the meaning of what is going to be said.The Syntactic level is the grammatical structure of the vocalises in the planned utteranceThe morphological level is the morphemes ( elementary units of meaning of interchange forms) in the planned sentence.The Phonological level is the basic unit of sound within a sentence. In summing up to the main structure of the SAT model a representation is organize at each level. Pre-Planning is more particular at the semantic level. at that place are categorical rules at each level, which impose co nstraints on accompaniment categories and category combination.The internal lexicon (dictionary) is considered to be a constructionist network it includes nodes for concepts, words, morphemes and ph iodinemes. So when one node is activated it sends a message to activate all different nodes connected to it.The later computational model WEAVER++ was put forwards by Levelt, Roelofs, and Meeyer (1999) derived from Lefvelt (1989).The model is based on the assumptions that there is a founder forward activation network spreading through the network and does not go back. There are 3 levels in the network the highest level of nodes represented are lexical the second level are lemmas which are abstract words from the mental lexicon and the lowest level are the nodes in support of morphemes the basic unit of meaning and phonemes. The network does not guard any inhibitory links. The production of speech follows through the stages exactly serial. A word error will occur if the level of acti vity in the node does no match to the appropriate node higher up. There are 6 stages of processing in the WEAVER++ Theory 2 more than the SAT theory. First the Conceptual preparation stage where the lexical concepts are activated. Stage 2 comes the Lexical selection where an abstract word or lemma is Selected along with its syntactic features. The Morphological convert is The basic word form derived from the lemma activated. Stage 5 is the Phonetic encoding is where the speech sounds are set. Articulation is the Final stage defines the way the word is pronounced.