Fleming, Einstein, President Garfield, Benjamen Franklin, Michelangelo, Leonardo da Vinci, Ed McGivern were ambidextrous.
There are modern day athletes who train right and left handed in their sports. I have seen articles about baseball, tennis, and basketball players, who train right and left handed, and have excelled in their sport.
Of these people, Ed McGivern is the only one I have been able to research.
Ed McGivern is the greatest pistol shooter who has ever lived. He wrote a book "FAST AND FANCY REVOLVER SHOOTING" still in print. Watching his shooting ability on TV, and reading his book, inspired me to try playing music left handed. On page 75, he describes how he trained, and that he practiced left handed until he became as proficient as he was right handed.
When I read his book, I could not help but notice, McGivern's articulate, precise, even eloquent writing throughout his book.
I don't know much Einstein. He thought "outside of the box", and as a result changed civilization. I don't know if he consciously made a concerted conscious effort at being ambidextrous in some manner, but I believe his theories in physics came about as a result of what you described, in your wording:
"Integration of left brain and right brain: logic and reasoning coupled with imagination and creativity".

Building Baby's Brain:

The Role of Music

by Diane Bales, Ph.D.

"Researchers believe that musical training actually creates new pathways in the brain."

Music has a powerful effect on our emotions. Parents know that a quiet, gentle lullaby can soothe a fussy baby. And a majestic chorus can make us swell with excitement. But music also can affect the way we think.

In recent years, we've learned a lot about how the brain develops. Babies are born with billions of brain cells. During the first years of life, those brain cells form connections with other brain cells. Over time, the connections we use regularly become stronger. Children who grow up listening to music develop strong music-related connections.

Some of these music pathways actually affect the way we think. Listening to classical music can improve our spatial reasoning, at least for a short time. And learning to play an instrument may have an even longer effect on certain thinking skills.

Does Music Make Us Smarter?

Not exactly. Music seems to prime our brains for certain kinds of thinking. After listening to classical music, adults can do certain spatial tasks more quickly, such as putting together a jigsaw puzzle.

Why does this happen? The classical music pathways in our brain are similar to the pathways we use for spatial reasoning. When we listen to classical music, the spatial pathways are "turned on" and ready to be used.

This priming makes it easier to work a puzzle quickly. But the effect lasts only a short time. Our improved spatial skills fade about an hour after we stop listening to the music.

Learning to play an instrument can have longer-lasting effects on spatial reasoning, however. In several studies, children who took piano lessons for six months improved their ability to work puzzles and solve other spatial tasks by as much as 30 percent.

Why does playing an instrument make such a difference? Researchers believe that musical training creates new pathways in the brain.

Why Classical Music?

The music most people call "classical"--works by composers such as Bach, Beethoven, or Mozart--is different from music such as rock and country. Classical music has a more complex musical structure. Babies as young as 3 months can pick out that structure and even recognize classical music selections they have heard before.

Researchers think the complexity of classical music is what primes the brain to solve spatial problems more quickly. So listening to classical music may have different effects on the brain than listening to other types of music.

This doesn't mean that other types of music aren't good. Listening to any kind of music helps build music-related pathways in the brain. And music can have positive effects on our moods that may make learning easier.

SELECTED REFERENCES
Fagen, J., Prigot, J., Carroll, M., Pioli, L., Stein, A., & Franco, A. (1997). Auditory context and memory retrieval in young infants. Child Development, 68, 1057-1066.

Rauscher, F. H., Shaw, G. L., Levine, L. J., Wright, E. L., Dennis, W. R., & Newcomb, R. L. (1997). Music training causes long-term enhancement of preschool children's spatial-temporal reasoning. Neurological Research, 19, 2-8.

Viadero, D. (1998). Music on the Mind. Education Week, April 8, 1998.

Wallace, W. T. (1994). Memory for music: Effect of melody on recall of text. Journal of Experimental Psychology: Learning, Memory, & Cognition, 20, 1471-1485.


Reprinted with permission from the University of Georgia.
Bales, D. (1998). Building Baby's Brain: The Role of Music. Athens, GA: University of Georgia, College of Family and Consumer Sciences.

I think this topic is important in PTSD.
It’s not about trying to become an ambidextrous genius, or even being ambidextrous. It is about basic biology, and how people with PTSD can benefit from using both cerebral hemispheres, by practicing an activity right and left handed that is neurologically intense.
To illustrate what I mean, I am going to place a time frame for what happened with me, using events which are relevant to this topic.
1959 - born, grow up with abusive father.
1980 – started playing acoustic music, at the age of 21. I continue this up to this day.
2000 – intervention forced me into drug rehab, I was addicted to hydrocodone. This is from my story “I Believe PTSD is Curable”
“Once at the facility, I underwent lengthy and very extensive psychological testing. I was told I had PTSD, and in addition I seemed to have multiple diagnoses. I told them I already knew about the PTSD. I did ask what could be done for it. There was very little that could be done, if anything. But they could get me into a life of sobriety, and that would make my life better.
I was also diagnosed as severely schizoid. Schizoid means “like schizophrenia”. Severe enough, that for all real purposes, my life was identical to a person with true schizophrenia.”
2002 – 2nd intervention forced me into a 2nd rehad. Again the following is from the same story.
“Throughout your life, you have been using a psychological defense mechanism we call compartmentalization. That means when something traumatic happened, you put it in the back of your mind, kind of like a little box. Well now you do not have any boxes left. You have used them all." I remember the words, used up, being mentioned. He also said, "You can not take another hit in life. You will kill yourself."
2003 – continued to struggle with ptsd and dysfunctional life.
12/2003 – start playing music left-handed. 3 months later
3/2004 – announce to family, friends, and coworkers, I don’t think I have PTSD.
4/2004 – voluntarily undergo psychiatric testing. Again from the same story
“The head psychologist, who had a Ph.D. from a prominent university, went over the results with me. The tests showed that there was not anything that was wrong, and she was confused as to why I was even there. I asked her specifically if the results indicated PTSD, and she specifically stated there were no symptoms of PTSD, or anything else, for that matter, indicated on the test.”

What is written above was easy to write about and describe, but the rest is not so easy, because there are not any words for it that I have been able to find, so please bear with me.
In addition, in March 2004, another phase of healing started to occur, and I think it relates to our topic.
I have seen individuals in 12 step programs struggle for a time, then a light comes on, you can see it on a person’s face. I have heard it called “a moment of clarity”. Confusion, pain, desperation, give way to a calm peaceful feeling. In AA I experienced it a time or two, myself.
Well this was like “an HOUR OF CLARITY”. It happened without fail, every day and became a regular part of my life. It happens upon awakening, every day, and lasts for about an hour, right after I would wake up. It is very, very peaceful.
I am certain this occurred because of an existing hemispherical imbalance of some type, because of the PTSD. I believe this occurs because our mind has a capacity for balance, if we give it the means to do so.
I no longer have flashbacks, I don’t jump out of my skin at sudden noises. I don’t have nightmares, and my mind is not stuck on traumatic events from years ago. I am not depressed, or suffer from undo anxiety. I do not take ANY psychotropic meds, and I will have 5 years of sobriety this Thursday 2/22/7.

March 05, 2007 12:01 AM Eastern Time

STANFORD, Calif.--(BUSINESS WIRE)--Severe stress can damage a child’s brain, say researchers at the Stanford University School of Medicine and Lucile Packard Children’s Hospital. The researchers found that children with post-traumatic stress disorder and high levels of the stress hormone cortisol were likely to experience a decrease in the size of the hippocampus — a brain structure important in memory processing and emotion.

Although similar effects have been seen in animal studies, this is the first time the findings have been replicated in children. The researchers focused on kids in extreme situations to better understand how stress affects brain development.

“We’re not talking about the stress of doing your homework or fighting with your dad,” said Packard Children’s child psychiatrist Victor Carrion, MD. “We’re talking about traumatic stress. These kids feel like they’re stuck in the middle of a street with a truck barreling down at them.”

Carrion, assistant professor of child and adolescent psychiatry at the medical school and director of Stanford’s early life stress research program, and his collaborators speculate that cognitive deficits arising from stress hormones interfere with psychiatric therapy and prolong symptoms.

The children in the study were suffering from post-traumatic stress disorder, or PTSD, as a result of undergoing physical, emotional or sexual abuse, witnessing violence or experiencing lasting separation and loss. This type of developmental trauma often impairs the child’s ability to reach social, emotional and academic milestones.

“We’d really like to understand why some children are more resilient than others, and what the long-term effects of extreme stress are,” said Carrion, who is the first author of the research, to be published in the March issue of Pediatrics. “We know, for example, that these children are at higher risk of developing depression and/or anxiety as adults.”

One theory posits that everyone carries an ongoing stress burden that accumulates throughout life. Once a certain threshold is reached, either through one or two very traumatic events or through chronic, high levels of stress, adults and children can begin to exhibit PTSD symptoms such as re-experience (including flashbacks, intrusive thoughts or nightmares), avoidance and emotional numbing, and physiological hyperarousal (such as an elevated resting heart rate). These behavioral symptoms make PTSD difficult to differentiate from other conditions such as attention deficit/hyperactivity disorder.

Children predisposed by genetics or environment to be more anxious than their peers are also more likely to develop PTSD in response to emotional trauma, perhaps because their responses to other life experiences simply left them closer to that threshold than less-anxious children.

The researchers studied 15 children from ages 7 to 13 suffering from PTSD. They measured the volume of the hippocampus at the beginning and end of the 12- to 18-month study period. After correcting for gender and for physiological maturity, they found that kids with more severe PTSD symptoms and higher bedtime cortisol levels (another marker of stress) at the start of the study were more likely to have reductions in their hippocampal volumes at the end of the study than their less-affected, but still traumatized peers.

It is significant that the change in the hippocampal volume corresponds to both PTSD symptom severity and increased cortisol levels. Cortisol belongs to a class of human hormones known as glucocorticoids that have been shown to kill hippocampal cells in animals. In a vicious cycle, a reduction in hippocampal size can make it more difficult for a child to process and deal with traumatic events, which in turn may raise both stress and cortisol levels that cause even more damage.

“Although everyday levels of stress are necessary to stimulate normal brain development, excess levels can be harmful,” said Carrion, likening the biological effects of increasing amounts of stress to an inverted U. “One common treatment for PTSD is to help a sufferer develop a narrative of the traumatic experience. But if the stress of the event is affecting areas of the brain responsible for processing information and incorporating it into a story, that treatment may not be as effective.”

Carrion and his colleagues are now using an imaging technique known as functional MRI to visualize whether and how the children’s brains differ when performing emotional and cognitive tasks.

“What we have now is basically a snapshot,” said Carrion. “We can’t yet say much about function. But we know that PTSD is chronic and pervasive. Hopefully with further research we can develop more effective, targeted interventions to help these kids.”

The study was funded by the National Institutes of Health, the National Alliance for Research on Schizophrenia and Depression, the American Foundation for Suicide Prevention and the Aloha Foundation.

Other co-authors include professor of psychiatry Allan Reiss, MD, and former postdoctoral scholar Carl Weems, PhD, who is now an associate professor of psychology at the University of New Orleans.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions — Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children’s Hospital at Stanford. For more information, please visit the Web site of the medical center’s Office of Communication & Public Affairs at http://mednews.stanford.edu.

Ranked as one of the best pediatric hospitals in the nation by U.S.News & World Report and Child magazine, Lucile Packard Children's Hospital at Stanford is a 264-bed hospital devoted to the care of children and expectant mothers. Providing pediatric and obstetric medical and surgical services and associated with the Stanford University School of Medicine, Packard Children's offers patients locally, regionally and nationally the full range of health care programs and services — from preventive and routine care to the diagnosis and treatment of serious illness and injury. For more information, visit http://www.lpch.org.
Contacts

Somewhere around June 2003, one of my supervisors gave me a dirty look. I ended up in the emergency room as a result of the panic attack I had. Once again, my mind just kind of froze and blacked out, and I just could not process anything. Afterwards, my neurologist ran every test he could think of. He also had me do an MRI. I'm sure he still has this, but I never really asked him about this. It reminds me of a sentence in your post,
"One theory posits that everyone carries an ongoing stress burden that accumulates throughout life. Once a certain threshold is reached, either through one or two very traumatic events or through chronic, high levels of stress, adults and children can begin to exhibit PTSD symptoms such as re-experience (including flashbacks, intrusive thoughts or nightmares), avoidance and emotional numbing, and physiological hyperarousal (such as an elevated resting heart rate). These behavioral symptoms make PTSD difficult to differentiate from other conditions such as attention deficit/hyperactivity disorder."
This used to happen quite often, even from someone just giving me a wrong kind of look. Maybe there is a thresh-hold of some type. AT the second treatment center I was in, I did all of the psych testing, and somehow they finally diagnosed that. I had told previous psychiatrists and counselors, but they either did not believe me, or they were unfamiliar with this.
Dr Roerich, and everyone else, PLEASE believe me. I'm sure you can tell an honest account when you see it. Someone once said, that the truth has a certain ring to it. That statement is true.
This type of "blacking out" has not occurred, within the past 3 years.
I work as a clinical pharmacist in a call center. My current supervisor is a jerk, and I have had several confrontations with him, another one is pending. I can stand my ground, like you wouldn't believe, and if someone gives me dirty look, I can just give them one right back.

lrs,

I have no doubt that when clinical improvement occurs that there are reasons for this. Basic science can lag behind to explain these changes but does not leave doubt in my mind as to the improvement itself. It is new medical evidence. If steel has a melting point, then each of us has thresholds for stress beyond which panic attacks may occur or worsening depression or PTSD.

To thine own self be true and continue to stand your ground. I thank you for your post and believe what you have shared with us.

Regards,

Roerich

I'm going to refer to Dr. Schiffer in the previous article from which you previously posted a portion. This is from the same article from:
Can the Different Cerebral Hemispheres Have Distinct Personalities?
Evidence and Its Implications for Theory and Treatment of PTSD and Other Disorders
Fredric Schiffer, MD

This is from the last page of Dr Schiffer's Article:


"My anecdotal observations lead me to believe that as the troubled
hemisphere improves it forms a better relationship with the other side. In this sense the hemispheres become more harmonious or balanced, but such improvement is possible only after the troubled side becomes healthy enough to begin to engage in that relationship. [/i]This model resembles the relationship between a traumatized child and a therapist or a healthy parent."

Dr Roerich provides some very good insight. Have not heard from him lately. Does he still participate?

He is still around, just very busy with his work now.