Speech Development
Professor: Dr. F. Towhidkhah
Student: S. Shahsavarani
First Semester 2008-2009
Outline:
1- Introduction
2- Some Novel Works on Speech Development
3- Articulatory Adaptation
4- Sensory Motor Coupling
5- References
Human Motor Control Course
First Semester
2008-2009
Outline:
1- Introduction
2- Some Novel Works on Speech Development
3- Articulatory Adaptation
4- Sensory Motor Coupling
5- References
Human Motor Control Course
First Semester
2008-2009
Introduction
In the brain, the concepts and units of language must ultimately be
translated into motor system
Motorvariables.
Neuron Pools
When humans speak, we produce sentences, phrases, words, and
The groups of neurons lying in
syllables that listeners understand.
the BRAIN STEM or spinal cord
that innervate
single
In order for people
to speak, athe
brainmuscle…
must generate motor
commands to control activation of many different motor neuron
pools.
These motor neuron pools include those innervating muscles of the
articulators, the larynx, and the chest wall.
Human Motor Control Course
First Semester
2008-2009
Introduction
Articulators
Chest Wall
Larynx
Learning
Language
Units
Motor Speech
Region
Brain Stem
Speech
Muscles
Adaptation
Sentences
phonemes
phrases
Words
Human Motor Control Course
First Semester
2008-2009
Motor Commands
Motor Neuron Pools
Outline:
1- Introduction
2- Some Novel Works on Speech Development
3- Articulatory Adaptation
4- Sensory Motor Coupling
5- References
Human Motor Control Course
First Semester
2008-2009
Some Novel Works on Speech Development
Research Groups in Development of Speech
Speech Motor Development
Drs. Anne Smith
Department of Speech, Language, Hearing Sciences,
Purdue University, USA
Stuttering
development of speech production
The Physiologic Development of Speech Motor Control
Jordan R. Green
Department of Communicative Disorders
University of Wisconsin, USA
His research projects are designed to identify the motor skills that are
essential for normal speech and feeding development, to understand how
various neurologic impairments affect speech and swallowing, and to
develop innovative methods for studying speech motor performance.
Human Motor Control Course
First Semester
2008-2009
Some Novel Works on Speech Development
Computational Model in Development of Speech
DIVA Model (Directions In to Velocities of Articulators)
Prof. Frank H. Guenther
Department of Cognitive and Neural Systems,
Boston University,1994
Sensorimotor Coupling Model
Dr. Gert Westermann
Eduardo
Reck Miranda
Oxford University
Professor
in Computer Music
Developmental
Cognitive
Neuroscience
University
of Plymouth,
United
Kingdom
Development
speech
in infancy
His
research isofaimed
at sounds
understanding
how and
why people create, perform and listen to music.
Human Motor Control Course
First Semester
2008-2009
Outline:
1- Introduction
2- Some Novel Works on Speech Development
3- Articulatory Adaptation
4- Sensory Motor Coupling
5- References
Human Motor Control Course
First Semester
2008-2009
Articulatory Adaptation
(Jordan R. Green)
 Speaking is among one of the most complex motor acts performed by humans.
It requires co-ordination of 70 muscles serving the respiratory, laryngeal, and
vocal tract systems. Moreover, speech is produced at a remarkably fast rate,
approximately fifteen sounds per second.
 Children typically do not master the sounds of their language until 8 years of age,
and some features of speech do not exhibit adult-like consistency until
adolescence.
 In early speech, the probability that a sound will be correctly produced depends
on the match between existing coordinative capabilities and those required
by each sound.
 Young children challenged by their limited options for producing different
sounds are obligated to adopt strategies for approximating adult-like speech.
Human Motor Control Course
First Semester
2008-2009
Articulatory Adaptation
(Jordan R. Green)
 These early articulatory adaptations provide a window into the developmental
status of the neuromotor system and cognitive/perceptual processes.
 Careful study of these behaviors is providing new insights into the many
processes involved in learning to speak.
 Unlike other motor systems (e.g., reaching, locomotion), the developmental
course of articulation is largely unknown, although it is a matter of fundamental
importance for understanding the physiologic basis of both typically and
disorder speech development.
 Research in speech motor development has been slowed by the absence of
methods for obtaining physiologic measures of articulation in young
children.
Human Motor Control Course
First Semester
2008-2009
Articulatory Adaptation
(Jordan R. Green)
Lip and Jaw Coordination (EXPERIMENT)
Bilabial Consonants
A speech
sound
produced
by using
Productions of syllables
containing
bilabial
consonants
were observed from
lips:
in English, b,2-year-olds,
p and m 6-year-olds, and
speakers in four age both
groups
(i.e.,1-year-olds,
are bilabials.
young adults)
A video-based movement tracking system was used to transduce movement of
the upper lip, lower lip, and jaw. The coordinative organization of these
articulatory gestures was shown to change dramatically during the first several
years of life and to continue to undergo refinement past age 6.
Human Motor Control Course
First Semester
2008-2009
Articulatory Adaptation
(Jordan R. Green)
Lip and Jaw Coordination (EXPERIMENT)
Human Motor Control Course
First Semester
2008-2009
Articulatory Adaptation
(Jordan R. Green)
Conclusion
 In summary, one result that has emerged from these experiments on early
speech development is that co-ordination of mandible precedes that of the
lips. The findings also suggest that the young child has a limited ability to
independently control the upper and lower lips. These constraints in early
articulatory co-ordination and control have predictable consequences on infants’
sound producing capabilities and may explain why children with differing
experiences acquire early sounds in a similar order.
 These findings probably reflect extensive changes in the biomechanical
composition of vocal tract structures and their neuromotor pathways.
Human Motor Control Course
First Semester
2008-2009
Outline:
1- Introduction
2- Some Novel Works on Speech Development
3- Articulatory Adaptation
4- Sensory Motor Coupling
5- References
Human Motor Control Course
First Semester
2008-2009
Sensory Motor Coupling
(Gert Westermann,Eduardo Reck Miranda)
 In recent years there has been mounting evidence that the pre-linguistic period
plays a major role in the development of phonology. It is often hypothesized that
the first speech-like articulations and the babbling phase between 5 and 10
months of age allow infants to develop a link between articulatory settings and
the resulting auditory consequences.
 More recent evidence suggests that this link is learned rather than innate,
focusing on evidence for the role of babbling in normal speech development. It
has been found that deaf infants do not babble normally, indicating the role of
audition for normal babbling, and that they subsequently often do not develop
intelligible speech. Infants that were prevented from normal babbling due to
tracheotomy likewise show abnormal patterns of vocal expressions that persist.
Human Motor Control Course
First Semester
2008-2009
Sensory Motor Coupling
(Gert Westermann,Eduardo Reck Miranda)
A Computational Model
This model learns a coupling between motor parameters and their
sensory consequences in vocal production during a babbling phase.
Co-variance Learning Rule
Human Motor Control Course
First Semester
2008-2009
Sensory Motor Coupling
(Gert Westermann,Eduardo Reck Miranda)
One input to a map will typically
activate several units, and the
response ri to an input x , that
is, how the neural map
“perceives”
that
input,
is
computed in a population code:
the response is the vector sum of
the positions of all units,
weighted by their activation
values:
Human Motor Control Course
First Semester
2008-2009
where pos i is the position of unit i , and
act i is its activation.
Such population codes have been found to
play a role for example in the encoding of
motor commands in the monkey cortex.
Outline:
1- Introduction
2- Some Novel Works on Speech Development
3- Articulatory Adaptation
4- Sensory Motor Coupling
5- References
Human Motor Control Course
First Semester
2008-2009
References:
1- Jordan R. Green, Christopher A. Moore, “The Physiologic Development of
Speech Motor Control: Lip and Jaw Coordination”, Department of Speech and
Hearing Sciences University of Washington, 2000
2- Gert Westermann, Eduardo Reck Miranda, “Modeling the Development of
Mirror Neurons for Auditory-Motor Integration”, J. New Music Research, 2002
3- Gert Westermann, Eduardo Reck Miranda, “A new model of sensorimotor
coupling in the development of speech”, J. Brain and Language, 2003
4- Anne Smith, “Speech Motor Development: Integrating muscles, movements,
and linguistic units”, J. Communication Disorders, 2006
Human Motor Control Course
First Semester
2008-2009
Thank you very much!
Any question?
Human Motor Control Course
First Semester
2008-2009