Lemma model
the architecture that supports word production consists of two subsystems. It intervenes between semantics and phonolgy and points to pertinent and morphosyntactic features.
Lexical selection
identifying the most appropriate word in the mental lexicon.
encoding
preparing the word's articulatory shape.
prosodification
determining the metrical structure of the target word
Phonetic encoding and articulation
involves precompiled units in the syllabary and generating the articulatory score to drive the vocal apparatus
The external feedback loop
monitors the auditory signals of self produced speech.
the internal feedback loop
monitors the convert processes of generating phonological words
The lemma dilemma
Some brain-damaged patients make semantic errors in just one modality of output in the oral modalitiy, but not written.
the DIVA model of speech motor control
Directions into velocities of Articulators: a computer simulation model of speech motor control. The DIVA model begins where the LEMMA model off (phonetic encoding and articulation)
Speech sound map SSM (feedforward control systems)
a repository of acquired speech sound representations, a starting point for articulation
articulatory velocity and position maps AVPM (feedforward control systems)
contain vocal tract representations that specify the articulatory score of utterance
the initiation map IM (feedforward control systems)
a module that sends "go" signals to prepared speech motor commands
Movement in the feedforward control systems
During speech production, activation of a particular unit in SSM engages the corresponding vocal tract motor commands in the AVPM, and those commands are released by the go commands in the IM
The auditory target map ATM (Auditory feedback circut)
a module that subserves auditory target representations (acoustic expectations) during speech production
Auditory state map ASM (Auditory feedback circut)
a module that represents speech related auditory input, including self-generated utterances
Auditory error map AEM (auditory feedback circut)
a module that computes discrepancies between the anticipated and the actual sounds of self-generated utterances
Feedback control map FCM (auditory feedback circut)
a module that adjusts or updates articulatory commands in light of sensory feedback
Somatosensory target map STM (somatosensory feedback)
a module that subserves somatosensory target representations during speech production
Somatosensory state map SSM (somatosensory feedback)
a module that represents tactile and proprioceptive sensations associated with speech production
the feedback control map FCM (somatosensory feedback)
the same as described for auditory feed back circut
somatosensory error map SEM (somatosensory feedback circut)
a module that computes discrepancies between the anticipated and actual tactile sensations associated with speech production.
Speech sounds map damage will result in...
apraxia of speech
Bilateral damage to the articulatory velocity and position map results in..
spastic dysarthria
damage to the initiation map will result in...
akinetic mutism and transcortical motor apraxia