The retraining of left-handed persons to write with the non-dominant right hand in childhood was the norm in Germany until the 1990s. The "good, right hand" was supposed to be used, but the re-education can have far-reaching consequences for the persons concerned. The Chair of Human Movement Science investigated the extent to which writing with the actually dominant, left hand can be learned in adulthood.
The basis of the study was the Bachelor's thesis supervised by Prof. Dr. Joachim Hermsdörfer and written by Laura Stetter, who is now a Master's student in Health Science at the Department of Sport and Health Sciences. The data set was provided by the psychologist Dr. Barbara Sattler, founder of the First German Consulting and Information Center for left-handers and converted left-handers, who initiated the study together with Dr. Christian Marquardt. The results have now been published under the title "Handwriting kinematics during learning to write with the dominant left hand in converted left-handers" in the journal "Scientific Reports".
The proportion of left-handed writers in Germany varies depending on the source, but has risen noticeably in recent years. One of the reasons for this is that re-educating left-handers in Germany can now even be a punishable offence. This is because re-education can have a negative impact on mental abilities, such as concentration, resilience or responsiveness.
"The special feature of our study was the duration and intensity of the training, which we were able to follow individually over a long period of time, and handwriting as the fine motor skill of highest complexity, which each of us learns. The study thus extends our knowledge about the learning capacity of humans. The results can be transferred to situations when, for example, adaptations or new learning become necessary due to ageing or illness."
Dr Sattler's graphomotor training program, which examined the kinematics of the writing movements of (retrained) left-handers, lasted two years. "I approached the topic of retraining to the left hand with great respect, also because I noticed very quickly that automated writing and freeing up resources for thinking at the same time often does not work initially for many retrained left-handed people. The results of this scientific study confirm that even automated writing must rely on a movement program that requires time to learn and practice. It is not only the letters and words that we need to know, we also need the automated movement program," explains Sattler.
The twelve participants between the ages of 20 and 50 went through seven tests and met once a month for a check-up with the psychologist - there was also a control group with original left-handers. The requirements were successively increased. First, the test persons were given basic tasks such as scribbling, hatching, squiggling and tracing. The results of these initial exercises were evaluated. This showed an increase in the writing frequency of both hands.
After just under six months, the participants began to write complex writing tasks such as sentences and texts - after twelve months, most of the test persons were already able to write complete texts and to write relatively automatically. It turned out that in the course of the practice phases (never longer than 20 minutes per day), the left hand came closer and closer to the performance of the right hand, but did not reach the level of the non-converted left-handed writers.
"This may be due to different reasons. It may be that the two-year period was too short to produce an exact match, or that certain areas in the brain develop differently when writing with the other hand. Of course, the age-related decline in motor learning ability also plays a role. But the results show that the program works and it is exciting to see that plasticity is present even in adulthood and that retraining is possible," explains Stetter.
To the homepage of the Chair of Human Movement Science
To the study "Handwriting kinematics during learning to write with the dominant left hand in converted left-handers" in the journal "Scientific Reports"
Contact:
Prof. Dr. Joachim Hermsdörfer
Chair of Human Movement Science
Georg-Brauchle Ring 60/62
80992 München
phone: 089 289 24550
e-Mail: joachim.hermsdoerfer(at)tum.de
Text: Bastian Daneyko
Photos: Pexels/TUM/private