Physical therapists, occupational therapists, and sports coaches use motor learning and control to maximize the effectiveness of their therapies and coaching. What if speech-language pathologists (SLPs) studied motor learning and control?
Improving Cognitive Stage Speech Motor Learning
In the first or cognitive stage of motor learning, you observe an instructor performing a motor skill that’s new to you. But speech-language pathologists may be the wrong people to model fluent speech motor skills. When learning a new motor skill, novices learn best by observing another novice making mistakes, then getting it right.
In contrast, observing a skilled person perform the task flawlessly doesn’t do you much good. For example, millions of people watch Michael Jordan play basketball. Few of those people could go out on a basketball court and repeat his moves. The exceptions are people who are already skilled and want to get better, e.g., college basketball players can improve their game by watching the pros.
A stutterer watching a speech-language pathologist model gentle onsets is like Joe Sixpack watching Michael Jordan. The stutterer might learn more if the speech-language pathologist modeled the mistakes her other clients have made, and then showed how to correct those mistakes. Or the speech-language pathologist prepared a video of her previous clients making mistakes and then learning to correct their mistakes. Best is to do group therapy, such as at an intensive residential program, where you see other stutterers making mistakes and you help them correct their mistakes, or when you make mistakes they help you.
Improving Associative Stage Speech Motor Learning
In the second or associative stage of motor learning, you learn to perform and refine a new motor skill. Are there fluent speech motor skills that aren’t taught in fluency shaping stuttering therapy programs?
Lower Vocal Pitch
Speaking at a lower vocal pitch requires relaxing one’s vocal folds, and reduces stuttering.[ref]Ramig, P., Adams, M. Vocal changes in stutterers and nonstutterers during high- and low-pitched speech, Journal of Fluency Disorders, Volume 6, Issue 1, March 1981, Pages 15-33[/ref] Unlike other fluency-enhancing techniques such as a slow speaking rate or gentle onsets, listeners like the sound of a lower vocal pitch. A lower vocal pitch communicates confidence and relaxed authority. Some listeners even say that a lower vocal pitch sounds “sexy.” Speaking with a lower vocal pitch makes one feel relaxed and confident. Yet this technique is not a target behavior in fluency shaping stuttering therapy programs.
According to multichannel processing theory, performing two tasks is easier if you integrate the tasks. For example, dancing while playing the saxophone is easier than playing tennis while playing the sax. Using fluency shaping motor skills while paying attention to a conversation should be easier if the motor skills relate to the conversation. If you’re trying to communicate that you’re relaxed and confident, then using a “slow normal” speaking rate with a lower vocal pitch should be easier than using gentle onsets.
This technique can be trained by using relaxed, diaphragmatic breathing while feeling (with your fingers or your throat) and/or listening to your vocal fold vibrations. Begin by humming or saying “ahhhh.” Bring the pitch up, then down, then up again, then down further. Repeat until your feel and hear yourself humming at a very low pitch. Now speak slowly, stretching vowels, while keeping your vocal pitch low.
Notice that your vocal volume drops as you lower your vocal pitch. Don’t try to speak loudly with a low vocal pitch, you may damage your vocal folds. A lower vocal volume is usually acceptable unless you’re speaking in a noisy environment or to a person with hearing loss.
Frequency-shifted auditory feedback (FAF) induces a lower vocal pitch in non-stutterers.[ref][ii] Elman, J. (1981). “Effects of frequency-shifted feedback on the pitch of vocal productions,” Journal of the Acoustical Society of America, 70 (1). Burnett, T.A., Senner, J.E., and Larson, C.R. (1997). “Voice F0 responses to pitch-shifted auditory feedback: A preliminary study,” J. Voice, 11, 202-211. Burnett, T.A., Freedland, M.B., Larson, C.R., Hain, T.C. (1998). “Voice F0 responses to manipulations in pitch feedback,” Journal of the Acoustical Society of America, 103 (6) June 1998.[/ref] One study tested whether a half-octave FAF downshift changes stutterers’ vocal pitch. The results were negative[ref][iii] Natke, U., & Kalveram, K.Th. (2001) Fundamental frequency and vowel duration under frequency shifted auditory feedback in stuttering and nonstuttering adults. In H.-G. Bosshardt, J. S. Yaruss & H. F. M. Peters (Eds.), Fluency Disorders: Theory, Research, Treatment and Self-help. Proceedings of the Third World Congress of Fluency Disorders in Nyborg, Denmark. Nijmegen: Nijmegen University Press, 66-71. Natke, U., Grosser, J., & Kalveram, K.Th. (2001) Fluency, fundamental frequency, and speech rate under frequency shifted auditory feedback in stuttering and nonstuttering persons. Journal of Fluency Disorders, 26, 227-241.[/ref]> but I believe that a greater frequency shift, combined with the headphones we use today, would have positive results. In other words, if you have a FAF device, set it for one-half or one octave down, and use the best-quality headphones you have. Then say “ahhhh” or speak slowly with stretched vowels, trying to slow your vocal fold vibrations to match the frequency you hear in the headphones.
Lower vocal pitch may be difficult for women speech-language pathologists to model, or for children or women stutterers to use (Lauren Bacall might contradict that statement!). Adult men are more capable of lowering their vocal pitch. Listen to an audio book read by a male actor and then listen to another audio book read by a female actor: you’ll likely hear that the male actor can perform a wider variety and range of character voices.
Autonomous Stage Motor Learning: Automatic, Effortless Fluency
The third or autonomous stage of motor learning moves you from closed-loop motor control to open-loop motor control. The autonomous stage makes the target motor skills automatic and effortless.
Autonomous stage motor learning results from:
- Practicing target muscle movements faster and harder,
- While making no errors,
- In stressful situations,
- With an ideal practice schedule,
- For about three million repetitions.
For example, you take tennis lessons. Your coach shows you how to grip the racket properly, and swing at the ball. At first you execute this movement slowly, with little force. As your skill improves, you swing faster, and hit the ball harder. When you make a mistake, your coach stops you and makes you begin again, slowly. At first your coach hits you easy balls. Then he hits harder balls to you, making the game stressful. Then you play tennis regularly. Over several years your game improves.
Where Stuttering Therapy Fails
Most stuttering therapy programs do little to train autonomous motor learning:
- Your speech-language pathologist tells you to make a conscious effort to speak fluently You’re told that if your fluency fails, it’s your fault for not concentrating on your speech.
- All practice is done with relaxed speech-production muscles. You never increase muscle tension.
- All practice is done at slow speaking rates.
- All practice is done in the speech clinic, or at home alone. You don’t do practice in high-stress situations.
Increasing Force and Speed
Stuttering therapy programs fail to train the autonomous stage of speech motor learning because of a counterintuitive aspect of stuttering. Stuttering is characterized by abnormally high activity in the brain’s speech motor control area. This results in excessive speech muscle activity. The obvious but wrong treatment for stuttering is to reduce speech-production muscle activity, i.e., to speak with relaxed breathing, vocal folds, and articulation muscles.
As noted earlier, speech-language pathologists see that slowing down and using closed-loop speech motor control eliminates stuttering. They reach the obvious but wrong conclusion that stuttering therapy should be done at slow speaking rates with relaxed muscles.
Fluency shaping therapy begins by training slow, relaxed, fluent speech motor skills. Similarly, golf and tennis instruction begins with slow, relaxed, correct movements. Golf and tennis instructors then have you increase your force and speed. In contrast, speech-language pathologists tell you not to increase your force and speed. It may seem counterintuitive, but after you master slow, relaxed fluent speech, you must increase both the speed and force of your speech, without making errors, to train automatic, effortless fluency.[ref] Thanks to Richard Harkness, who also found that increasing force and speed reinforced fluent speech motor programs.[/ref]
Increased speech force results in louder volume. Work on getting loud. But don’t shout or yell. Instead, project your voice. Vocal volume is a factor of both exhalation volume and vocal fold tension. Increase your exhalation volume while keeping your vocal folds relatively relaxed. This result is high volume with the intonations of normal conversational speech. Stage actors do this. I once dined in a restaurant where opera singers entertained at the tables. Have you ever been three feet from an opera singer? A soprano was deafeningly loud, but looked and sounded relaxed. Maybe stutterers should take opera lessons.
Increase your onset speed while maintaining long syllable duration. Pretend that your forearm is a sports car’s accelerator. When your fist is up, your vocal volume is quiet. As you push your fist down, your volume increases. When your fist is all the way down, you’re at maximum volume. Listeners one hundred feet away should hear you.
Slowly lower your fist to produce a gentle onset. Then slam your fist down fast to go from silence to maximum volume. Then hold that volume while stretching the vowel. Pull your fist up fast to end the word with speed. This is slow speech with maximum effort.
Be careful not to damage your vocal folds. Stop if you feel hoarse or start to lose your voice.
Shorten syllable duration from two seconds, to one second, to one-half second, to one-quarter second. Practice this both with relaxed, quiet speech, and with loud, forceful speech.
Using a practice word list and say each word four times:
- Slow and relaxed (quietly).
- Slow and projecting your voice (loudly).
- Relaxed (quietly) with a quick onset.
- Loudly projecting the word with a hard onset.
Where to Practice Force and Speed
It’s hard to practice loud speech in a small room. The ideal place to practice is an empty auditorium. Have your speech-language pathologist sit in the back row. Stand on stage and project your voice to her. She yells, “Can’t hear you!” until you reach ideal volume.
Another place to practice is near a building that produces an echo. A third place to practice is on a freeway overpass. Demosthenes, the stutterer who became the greatest orator of ancient Greece, projected his voice over breaking waves at the seashore. Work on projecting your voice over the waves of traffic.
Brain Gym Exercises
While I’m practicing speed and force I take breaks and do Brain Gym exercises. These cross-lateral exercises help your brain’s left and right hemispheres work together. I haven’t done a literature search to see the evidence of whether these exercises work but I like taking exercise breaks during speech therapy practice.
I do these exercises:
- Stand on my left leg, raise my right knee, touch my left elbow to my right knee, and hold while looking at the horizon. Repeat with the opposite knee and elbow.
- Stand with both feet on the ground but cross my legs. Hold my hands together with my arms down, cross my arms, and raise my hands to my chest. Close my eyes and tale long, slow, relaxed deep breaths.
- Move my left thumb in big horizontal figure 8’s in front of my face. Follow my thumb with my eyes. Do the same with my right thumb. Then hold hands and do the same.
Don’t do these exercises while you are speaking.
Reinforcing On-Target Speech
Increasing speed and force myelinates or reinforces neural pathways in your brain. A mistake reinforces the wrong neural pathways.
Learning to talk fluently requires talking fluently 100% of the time. That sounds like circular advice, and it is. Reinforcing motor skills is a “virtuous cycle.” Using target skills reinforces the skills, making the skills easier to use.
Conversely, stuttering reinforces undesirable speech motor skills (core stuttering behaviors) and bad communication habits (secondary behaviors). Stuttering sets up a “vicious cycle” instead of a “virtuous cycle.”
I wanted to improve my swimming. At first I could swim only one length of the pool and then I had to rest. But I got in the pool three times a week. I found that a small flotation device helped me swim five or ten laps. After two months something “clicked” in my brain and I swam half a mile. It was easy, almost effortless. I didn’t need the flotation device any more.
Then I moved to a building without a swimming pool, stopped swimming, and now I swim as poorly as I did before that summer.
Similarly, stutterers go to speech therapy three times a week for months. Then suddenly one day they find themselves talking fluently, without effort. If they discontinue speech therapy, this “lucky” fluency disappears and they go back to stuttering.
Stutterers’ brains have two sets of speech motor programs. Sometimes our brains pick the fluent speech motor programs. At other times our brains pick the stuttering speech motor programs. Speech therapy reinforces the fluent speech motor programs. Eventually this fluent speech becomes habitual. But during “lucky” fluency this habit is precariously balanced. One stressful day, in which you allow yourself to stutter, can reinforce the stuttering motor programs, and your “lucky” fluency is gone.
This is where you need a speech buddy. More on that in the final chapter.
Practicing Under Stress
Autonomous motor learning requires practicing a new motor skill in stressful situations.
Design a hierarchy of stressful situations. The first might be leaving a message on your speech-language pathologist’s answering machine. When you can do that comfortably and fluently, you might talk to telemarketers using closed-loop speech motor control (slow, fluent speech). Then you could join Toastmasters and make a series of speeches to your club.
The United States Postal Service studied workers learning to operate mail-sorting machines (similar to typewriters). All subjects received 60 hours of training. The scheduling varied among four groups.
- One group had two two-hour sessions per day, for 15 days.
- A second group had one two-hour session per day, for 30 days.
- A third group had two one-hour sessions per day, for 30 days.
- The fourth group had one one-hour session per day, for 60 days.
The first group (two two-hour sessions per day) learned fastest, but in the long run had the worst performance. The fourth group (one one-hour session per day) took the longest to get “up to speed,” but eventually had the best performance.
Surprisingly, the postal workers preferred the two-hour/two-session schedule, even though they had the worst performance. People are impatient. They don’t want to spend 60 days learning something, if they think there’s a 15-day shortcut.
Extinguishing Old Skills
We could simplistically conclude that you should practice stuttering therapy no more than one hour per day. But there’s a difference between speech therapy and mail sorting. The postal workers were learning a new motor skill. Stutterers have to learn a new motor skill and extinguish an old motor skill. As noted earlier, coaches often prefer to work with individuals who have never played a sport and haven’t learned bad habits, rather than work with experienced athletes and have to break their bad habits.
To extinguish an old motor skill you must stop doing it. Perhaps the ideal stuttering therapy is done one hour per day, and then you take a vow of silence the rest of the day. But that’s unrealistic. To burn new fluent neural pathways, and extinguish old stuttering neural pathways, you must use fluent speech every time you talk. You must never stutter. Each disfluency weakens your new fluent neural pathways and strengthens your old stuttering neural pathways.
Extinguishing a maladaptive motor skill isn’t the same as “breaking” a bad habit. Maladaptive motor skills enable you to perform a desirable behavior, but not as a well as a better motor skill. For example, touchtyping is better than two-fingered typing, but two-fingered typing also gets the job done. In contrast, picking my nose is an undesirable behavior. I wish that a teacher had taught me to touchtype when I was a child. I don’t wish that a teacher had taught me a better way to pick my nose.
Because maladaptive motor skills enable you to perform a desirable behavior, it’s hard to unlearn them and replace them with optimal motor skills. Stuttering isn’t like picking your nose. Your mother could slap your hand and stop you whenever you pick your nose. If she stopped you every time you stuttered, you wouldn’t be able to talk. Stuttering isn’t a bad habit.
Extinguishing a maladaptive motor skill may involve “one step forward, one step back” temporarily. To speak fluently, you may have to speak slower and use fluency shaping techniques.
Intensive Residential Speech Therapy Programs
Some stutterers go to intensive residential speech therapy programs. These programs typically last two or three weeks. You’re surrounded by speech-language pathologists and other stutterers, and isolated from the real world. At first you use two-second stretch all the time. Later you move to one-second stretch, then half-second, and finally “slow normal” (about a quarter-second per syllable).
Intensive residential speech therapy programs are like the postal workers who did the “short cut” training. In a few weeks of intensive therapy you learn to talk fluently. But many stutterers find that long-term results are disappointing.
How Long Does Autonomous Learning Take?
Gymnasts practice daily for about eight years to become proficient.
Motor learning researchers studied the manual (hand) skills of cigar-makers.[ref][iv] Kottke, F.J., Halpern, D., Easton, J.K.M., Ozel, A.T., Burrill, C.A. “The Training of Coordination.” Archives of Physical Medicine and Rehabilitation, Vol 59, December 1978, 567-572.[/ref] Beginner cigar-makers worked three times slower than experienced cigar-makers. Becoming fully skilled required making three million cigars.
Three million repetitions were also needed for Japanese pearl handlers to become proficient. The Suzuki method of teaching violin to children requires the production of about 2.5 million notes. Basketball, football, and baseball throws require about a million practice throws.
This suggests that making fluent speech automatic and effortless requires saying about three million syllables. At five syllables per second, talking four hours a day (just your time talking, not counting listening), you could produce three million syllables in six weeks.
If you got a job answering telephone calls, and you did your stuttering therapy skills on every call, and you spent your free time at Toastmasters clubs making speeches or volunteering at a hospital’s information desk, fluent speech might become automatic for you in six weeks.
But most stutterers practice between ten minutes and one hour per day. If they were silent the rest of the day, they’d say three million syllables somewhere between six months and three years.
No one has studied whether undesirable motor skills cancel out on-target practice. In other words, does a half-hour of on-target practice get cancelled out by not using fluency skills the rest of the day? Such a practice schedule might take years to produce automatic fluent speech—or might never work.