Speech-Language Pathology/Stuttering/Development of Childhood Stuttering
Stuttering isn't a physical disorder. It's not a psychological disorder. Stuttering is a developmental disorder.
Children grow up in a certain order. They crawl before they walk. They walk before they run. They run before they ride bicycles. They ride bicycles before they borrow your car keys.
Usually. Some children walk before they crawl. My three-year-old nephew borrows my car all the time. Just joking. I don't own a car.
At each stage of physical development, a child's brain develops too. E.g., crawling helps the child develop communication between the left and right hemispheres of his brain. If all goes well, the child's physical, neurological, and psychological systems develop together.
A small, sometimes imperceptible, developmental misstep in early childhood can nudge a child off the normal developmental track. The child then grows on an abnormal developmental track. A minor problem can develop into a major disability as the child grows up.
Some children can't hear the difference between short duration speech sounds. The difference between /b/ and /d/ sounds occurs within a few milliseconds (thousands of a second). Some children's brains' auditory processing isn't fast enough to hear fast speech sounds. To these kids, "bad" and "dad" are the same word, "bug" and "dug" are the same, and so are "buck" and "duck." (This is a form of central auditory processing disorder, or CAPD).
You'd think this would be a minor problem. After all, you know the difference between "sew" and "so." But it's not a minor problem. These children develop speech slower than other children. Slow speech development causes them to miss other developmental stages. Their grammar develops poorly. Listeners have difficulty understanding these children's speech. These children understand the difference between boys and girls, but interchange "he" and "she." They mix up past, present, and future tense.
Then these children are labeled mentally retarded, even though they're normal or even excel at non-language activities (e.g., building with Legos). They're put into special ed classes, with children who really are mentally retarded.
The children miss more developmental stages. As adults, these individuals may be unable to read, or have poor social skills, or be unable to work at more than menial jobs.
This disorder is called language-learning impairment (LLI). In the last ten years a treatment has been developed. These children can distinguish /b/ from /d/ if the words are slowed down. Children with LLI now play a computer game that trains them to hear the difference between short-duration speech sounds.
When their auditory dysfunction is corrected, the children develop normally. The children usually catch up with their peers, e.g., advancing four reading grade levels in six months.
Analogously, children's brains are like a railroad going from New York to Los Angeles. A little dysfunction can bump a child onto a sidetrack. The sidetrack may start out only a few feet from the main track, but twenty years later he's lost somewhere in South America.
Treatment is like giving the child a shove back onto the main railroad track. The child then zooms ahead to catch up with his peers.
(Brain scans show that adult stutterers have a different form of CAPD, which may affect how we hear our own voices or feel our speech-production muscles moving. No researchers have investigated whether children who stutter also have this form of CAPD, or if treating this form of CAPD stops stuttering from developing.)
- Wikipedia doesn't have an article about language learning impairment (LLI) but it has an article about specific language impairment (SLI).
Early Intervention Is Best
Stuttering is similar to LLI, in that something small nudges a child off the normal developmental track at the age of two or three. This small nudge causes the child to grow on an abnormal developmental path. By adulthood, the stutterer has developed a variety of core symptoms, secondary behaviors, and psychological problems.
The average age of stuttering onset is 30 months. I.e., two-and-half-years-old is the typical age that children begin to stutter. Stuttering rarely begins after age six.
65% of preschoolers who stutter spontaneously recover, in their first two years of stuttering. These children grow up to have normal speech. Some pediatricians tell parents to "wait and see" if a child outgrows stuttering on his own. But this advice is wrong. Children who stutter should be treated by a speech-language pathologist as soon as possible. (Schools provide free speech therapy to children as young as three years old.)
However, children who stutter longer are less likely to recover without treatment. Only 18% of children who stutter five years recover spontaneously.
The peak age of recovery is 3.5 years old. By age six, a child is unlikely to recover without speech therapy.
If your child is in grade school and has stuttered for five years, he or she will need a bigger shove to get back onto the normal development track.
Critical Ages in Stuttering Development
At two or three years old, children are quickly developing communication skills. Their brains are growing rapidly. A child's language skills may develop faster than his speech skills. He wants to communicate but can't easily and freely generate speech.
The child interjects "uh" and "um." He repeats words. He has silent pauses. He revises what he's saying in the middle of sentences, or leaves sentences incomplete. He's most dysfluent with long sentences, when interrupting or being interrupted, or during stressful periods, such as a divorce, the birth of a sibling, or moving to a new home.
Those are normal dysfluencies. All children have normal dysfluencies. Normal dysfluencies aren't stuttering.
The "experts" say that some children move from normal dysfluencies into stuttering. These children's frustration trying to talk leads them to push out words. The children tense their breathing, their vocal folds, and their lips, jaws, and tongues. The children struggle to talk, getting into longer repetitions, prolongations, and silent blocks.
Recognizing which behaviors are normal dysfluencies and which behaviors are stuttering is a key issue. The Stuttering Foundation of America has a videotape to help parents differentiate normal dysfluencies from stuttering.
Because children's brains are growing at this time, their stuttering behavior becomes hardwired. Their brains shift onto an abnormal development path. The "experts" have identified five stages children go through as stuttering develops, over months and years.
Or are the "experts" wrong? Some parents report that their children woke up one morning stuttering severely. These children went from normal dysfluencies to severe stuttering overnight. The children skipped the development stages in between.
In a later chapter, you'll learn that a disorder similar to stuttering is triggered by a streptococcal infection causing a child's immune system to attack his or her brain's putamen motor control area. It's possible that a similar autoimmune dysfunction could attack a child's left caudate nucleus speech motor control area, causing severe stuttering to develop overnight.
You'll also learn that three genes are linked to stuttering. These genes affect the neurotransmitter dopamine, which functions abnormally in adult stutterers. I.e., some children are genetically predisposed to a class of disorders that includes stuttering.
You'll also learn that adult stutterers have abnormal auditory processing. (This abnormality is different from the auditory processing abnormality that causes language-learning impairment.)
These questions are important because they affect what therapy should be effective for children. If the "experts" are right that stuttering develops in five stages, beginning with normal dysfluencies, then early intervention is paramount, but the therapy can be a gentle nudge (e.g., telling the parents not to interrupt when the child is speaking).
But if the "experts" are wrong, and some children develop severe stuttering without going through intermediate stages, then therapy should start with a big shove back onto the normal developmental track. This important issue—direct vs. indirect therapy—is addressed in the chapter Stuttering Therapies for Pre-School Children.
- ^ Merzenich, M., Jenkins, W., Johnston, P., Schreiner, C., Miller, S., and Tallal, P. “Temporal Processing Deﬁcits of Language-Learning Im-paired Children Ameliorated by Training,” Science vol. 271, January 5 1996, p.77-80.
- ^ Yairi, E., Ambrose, N. "Onset of stuttering in preschool children: Selected factors," Journal of Speech and Hearing Research, 35, 1992, 782-788.
- ^ Yairi, E. (1993) "Epidemiologic and other considerations in treatment efficacy research with preschool-age children who stutter," Journal of Fluency Disorders, 18, 197-220. Yairi, E., Ambrose, N. "Onset of stuttering in preschool children: Selected factors," Journal of Speech and Hearing Research, 35, 1992, 782-788.
- ^ Finn, Patrick. "Children Recovered From Stuttering Without Formal Treatment: Perceptual Assessment of Speech Normalcy," Journal of Speech, Language, and Hearing Research, 40, 867-876, August 1997.
- ^ Andrews, et al., "Stuttering: a review of research findings and theories," Journal of Speech and Hearing Disorders, 48, 226-246, 1983.
- Early Childhood Stuttering, by Ehud Yairi and Nicoline Ambrose (2004, ISBN 0890799857)