Week 2 (Models and Frameworks) Flashcards
Speech can be produced at rates of up to ______ syllables (or _____ phonetic segments) per second. Faster than any other discrete motor performance.
6-‐‐9 syllables (or 20-‐‐30 phonetic segments) per second
Speech involves more __________ than any other human mechanical activity
motor fibers
Speech must generate what?
an acoustic signal that is understood by other listeners as a linguistic message and affective message
In infancy, _________ is one of infant’s first ventures into speech motor control
– Separate neural control systems for _______ and _________.
babbling; speech and other oromotor functions
Explain development of speech motor control system through childhood, adulthood, advancing age
The speech motor control system continues to develop and mature into childhood (think motor plans/programs)
Adulthood is then focused on the maintenance and deployment of well established processes of speech motor control
• But with advancing age speech changes in precision, fluency, voice quality and communicative effectiveness
Define and explain what it includes: theory
– Overall conception that encompasses the known facts in a parsimonious way
– Typically includes a set of assumptions and a number of principles from which hypotheses can be derived
Define and explain: model
Simplified description of a complex system or process. – Always an abstraction or simplification.
– Modeling helps the scientist to identify important parameters
or elements of a system that is too complicated to be comprehended in its complete, natural form
5 general types of models of speech production
neural, articulatory, vocal tract, functional, motor control
Define: neural model
Accounts for nervous system processes that control speaking; may specify neural structures, control circuits, information flow, other neural
variables.
Define: articulatory model
Describes articulatory positions, movements, or configurations; typically specifies individual articulators (tongue, lips, jaw, velum)
Define: vocal tract model
Focuses on the shaping of the vocal tract for the production of speech; does not necessarily specify actions of individual articulators
Define: functional model
Accounts for the ways in which various types of information regulate speech production; variables may be linguistic (syllables, phonemes, etc), control signals (feedforward or feedback) or generally defined in terms of
movement sequence.
Define: motor control model
Describes the motor processes of the activation of muscles for the production of speech; usually expressed in motor terms, such as specification of muscle synergies or kinematic descriptions of movement.
3 critical issues facing speech production models
Serial order problem, degrees of freedom problem, context sensitivity problem
3 questions asked by serial order problem
– How are elements strung together?
– What are the elements of control? • Is it the Phoneme, syllable, word?
– Do the elements cohere in a larger structure (e.g. stress grouping?)
Define and explain: degrees of freedom problem
The speech system has potential for a large number of degrees of freedom.
– 70 different muscular degrees of freedom in production of speech
– Tongue, lips, jaw, velum, larynx and respiratory system possess
several possible types of movement (range, direction, speech and temporal combinations)
– Excessive degrees of freedom can allow a great degree of flexibility
– On the other hand, too many presents a challenge
• Expend a great deal of computational effort to manage a large number of degrees of freedom or somehow reduce them.
Define and explain: context-sensitivity problem
– The production of a sound varies with the context in which it is produced.
– Coarticulation
• At any one time the speech system shows adjustments for more than one segment
• Example – /s/ in soup produced with rounding of lips – /s/ in seep is not produced with such rounding and may even
be associated with lip retraction
Define and explain: Schmidt (1988) model of motor programming
In order to deal with storage and novelty problems Schmidt proposed
Generalized motor program (GMP)
• Based on notion of schema and uses recall memory to produce movement and recognition memory to evaluate response correctness
• GMP is a motor program for a class of action stored in memory with certain parameters that define the ultimate goal
• GMP has not been directly related to speech
Keele and Summers (1976) theory of motor programming
Motor programs might be generated by stringing together smaller
individually programmed units of behavior so the string is controlled by a single unit of one larger program (over time)
• Example: shifting gears in a car
Define: Levelt and Wheeldon (1994) model of motor programming
Translating acquisition of sequencing to the process involves in phonetic encoding
Define: mental syllabary (Levelt & Wheeldon- 1994)
Mechanism for translating the abstract phonological representation into a context-‐‐dependent phonetic representation
– Retrieved from a sensorimotor store
Define: gestural score (LEvelt and Wheeldon- 1994)
Think of musical score – One score for each of the five subsystems involved in articulation
(glottal, velar, tongue body and tip and lips) – One gestural score needed for /p/ (close lips, voiceless, burst of air)
– The gestural scores are abstract and specify the tasks to be performed, not the actual motor programs
Define and explain: Van der Mewre (1997) model of motor programming
- Need to work from a sound theoretical framework based on normal process of speech, language production for both research and management of communication disorders.
- This framework portrays the transformation of the speech code from one form to another as seen from a brain behavior perspective.
- This framework incorporates ideas from many other models/frameworks into a framework with real clinical relevance
Define and explain: speech
…the externalized expression of language – “the motor-‐‐afferent mechanisms that direct and regulate speech
movements” (Netsell, 1982)
4 facts about the “Intent to communicate verbally” domain
Intention or readiness to commence intentional behavior
• Regulated by fronto-‐‐limbic circuits
• Closely linked with affective input
• Originates in internal biological or cognitive needs of a person or in the external demands exerted by the environment
Errors in the intent to communicate verbally domain include
Absence or reduction in amount of verbal communication
2 facts about the linguistic-symbolic planning domain
Non-‐‐motor in nature • Semantic, syntactic, lexical, morphological, and phonological planning based on linguistic rules of a given language
Errors in the linguistic-symbolic planning domain include
Errors consistent with “aphasia”
5 facts about the motor-planning domain
- “Highest” level of the motor hierarchy
- Formulating the strategy of action by specifying motor goals
- Gradual transformation of symbolic units (phonemes) to a code that can be handled by a motor system
- Articulator specific, not muscle-‐‐specific
- Cannot be disentangled from motor programming “clinically”
Errors in the motor planning domain include:
- Slow, struggling speech with distortion and even apparent substitutions
- Slowed temporal flow of speech
3 facts about the motor-programming domain
“Strategies prescribe the general nature of plans and tactics give them particular specifications in space and time.”
• Programs specify muscle tone, movement direction, force, range, and rate as well as mechanical stiffness of the joints
• Muscle-‐‐specific
1 fact about the sensation domain
The hierarchy of plans and programs is transformed into non-‐‐learned automatic (reflex) motor adjustments
2 types of corrective and predictive sensorimotor actions
feedback and feedforward
3 types of feedback
proprioceptive, auditory, tactile
Define: proprioceptive feedback
sense of what the muscle itself is doing faster than exteroceptive feedback
Define: auditory feedback
exteroceptive provides information about completion of speech
movements and may play a roll in speech timing
Define: tactile feedback
exteroceptive; tactile-‐‐kinesthetic information with muscle
movements
4 contextual factors that highly influence feedback
voluntary v. involuntary speech
• motor complexity of the utterance
• familiar vs. unfamiliar utterances
• rate of speech
PCND Chart- Conceptualization
Components: Cognitively and affectively generated thoughts, feelings, and emotions, plus a desire to express them to achieve a goal
Neural Substrate: Widespread
Disorders affecting speech: general cognitive impairment (dementia, psychosis, confusion)
PCND Chart: Linguistic Planning
Components: Highly interactive semantic and syntactic processing ultimately taking a phonologic form
Neural Substrate: left hemisphere perisylvian cortex, with less specific contributions from subcortical structures (thalamus and basal ganglia)
Disorders affecting speech: Aphasia
PCND Chart: Motor planning or programming
Components: Formulation and retrieval of motor commands for production of phonetic segments and syllables at particular rates and with particular patterns of stress and prosody, based on acoustic (and other modality) goals and feedback
Neural substrate: 1. Dominant hemisphere –> somatosensory cortex, premotor cortex (Broca’s area), supplementary motor cortex, motor cortex, insula
- control circuits –>
- Limbic system –>
- right hemisphere –>
- Thalamus and reticular formation –>
Disorders affecting speech: apraxia of speech, dysarthrias (apraxia of speech), altered affect of prosody (aprosodia), dysarthrias
PCND Chart: Performance
Components: motor execution
Neural substrate: LMN’s (as controlled by direct and indirect activation pathways, control circuits, and feedback)
Disorders affecting speech: dysarthrias
PCND Chart: Feedback
Components: multimodality feedback to the above components
Neural substrate: Peripheral and central sensory pathways
Disorders affecting speech: dysarthrias and peripheral sensory - based speech disturbances
Why do we care about these models and frameworks>
Understanding them is integral to proper assessment and management of your patients with motor speech disorders
Define and explain: perceptual methods
Gold standard for clinical differential diagnosis, judgments of severity, and many decisions about management
Unfortunately:
1. Subject to unreliability among clinicians
2. they can be difficult to quantify
3. they cannot directly test hypotheses about the pathophysiology underlying perceived speech abnormalities
But also “in the hands (ears, eyes, and hands) of experienced clinicians, the auditory-perceptual classification of MSD’s is a valid and essential diagnostic and clinical decision-making tool
Define: Instrumental methods
Not widely used in management of MSD’s
Lacking standards and normative data
Define: acoustic methods
can visually display and numerically quantify frequency, intensity, and temporal components of the speech signal
Define: physiologic methods, 3 examples
move “upstream” towards the sources of activity that generate and control speech
Ex: electromyography, kinematic measures, and aerodynamic measures
Define: visual imaging methods, 3 examples
These instruments saddle the boundary between perceptual and physiologic measures, because although the visual images can be quantitatively analyzed, the instrumentally provided image usually is interpreted by way of non-quantified perceptual judgments by the clinician doing the examination
Ex: videofluoroscopy, nasoendoscopy, laryngoscopy, videostroboscopy
Duffy said: The evaluation of anyone with a suspected MSDbeginswith a __________. Any instrumental assessment that may follow is motivated and directed by the results of the perceptual assessment. If descriptive or diagnostic errors are made at this perceptual entry point, whatever follows may be misguided and misleading to both diagnosis and management.
perceptually based speech assessment
Duffy said: The usefulness of ___________ has been established. The degree to which other methods contribute to, modify, or contradict that usefulness is not yet entirely clear. This does not minimize the contribution of instrumental methods to the description, understanding, and quantification of MSDs, but it does argue that _____________. It also argues for requiring an adequate description of salient perceptual speech characteristics in any research that examines the acoustic or physiologic attributes of MSDs. The likelihood that any such research can be replicated, generalized to clinical populations, or meaningfully interpreted by clinicians or other researchers is greatly diminished or nullified without perceptual description.
perceptually based differential diagnosis, relative to its contribution to localization and diagnosis of neurologic disease;
perceptually based methods should be the foundation of clinical practice
Duffy said: The standard for judging the functional outcome of management of MSDs is most often based on auditory-perceptual judgments of speech and its ______, _____, and ______.
intelligibility, comprehensibility and efficiency
3 ways auditory-perceptual clinical assessment works: 3 signs? 3 things they result from abnormalities in? 4 types of control abnormalities?
Signs such as hypernasality, consonant imprecision
Result from movement abnormalities in range, velocity or direction
Most likely resulting from control abnormalities specifically: strength, tone, timing, coordination
Continued: 5 ways auditory-perceptual clinical assessment works
Patient has hypernasality
Because of involvement of soft palate
Appears range and force of movement are reduced
Hypothesize that the main reason is weakness
You may even be able to hypothesize the lesion site
2 steps of perceptual-auditory evaluation
- Listen systematically to all signs
2. Create hypothesis about the label of best fit
4 things to look at first in PAE:
strength, tone, timing, coordination
4 things to look at second in PAE
range, velocity, direction, force
After looking at those 8 things you can see what?
signs of speech abnormallity
5 categories of deviant speech characteristics
respiratory/laryngeal, resonance, articulation, prosody, other
4 types of respiratory/laryngeal deviant speech characteristics.
Respiration: Forced insp/exp, audible inspiration, inhalatory stridor
Pitch: pitch level, pitch breaks, monopitch, voice tremor, laryngeal myoclonus, diplophonia
Loudness: monoloudness, excess loudness variation, loudness decay, overall loudness
Vocal quality: Harsh voice, hoarse (wet); breathy (continuous vs. transient), voice stoppages, flutter
4 types of resonance deviant speech characteristics
hypernasality, hyponasality, nasal emission, weak pressure consonants
7 types of articulatory deviant speech characteristics
Imprecise consonants, prolonged phonemes, repeated phonemes, irregular articulatory breakdowns, distorted vowels, distorted articulatory groping, increased errors with increase rate
10 types of prosody deviant speech characteristics
Rate, short phrases, increase rate segments, increased rate overall, reduced stress, variable rate, inappropriate silences, short rushes of speech, excess and equal stress, syllable segmentation
7 types of other deviant speech characteristics
Slow AMRs, fast AMRs, irregular AMRs, poorly sequenced SMRs, vocal tics, palilalia, coprolalia
