Research by Professor Hartwig Siebner and colleagues have demonstrated that the structure of the brain reveals the competences of the hands; “Two hand knobs are located in the sensory and motor cortex controlling the motor function of the hands. If measuring the asymmetry of the hand knobs on the left and right side, it reveals if one prefers using the left or right hand” explains Professor Hartwig Siebner at DRCMR.
Figure 1: The blue stars mark the location of the two hand knobs. The red area marks the great median fissure separating the frontal lobe and the parietal lobe.
The ability to draw circles can be measured in the cerebral cortex
Even though individuals are right-handed it does not necessarily mean that their delicate motor control of their right hand is better than the left. A study by Professor Hartwig Siebner and colleagues from 2016 showed that ability to draw circles between right-handed with right and left hand is very diverse.
Many right-handed individuals are just as good at drawing circles with their left hand as their right hand meaning that they have symmetrical dexterity.
“The variation in dexterity is reveal by the microstructure of the brain pathways from the motor cortex to the spinal cord. The motor pathways are more asymmetrical if the dexterity is asymmetrical.” Explains Professor Hartwig Siebner .
Figure 2: The histogram shows the ability of 52 right-handed individuals to draw circles with their right and left hand. The red line marks that the individual is equally good with both hands.
Left-handed are probably the most creative
Much research has been conducted to understand the difference in behavior and mentality of left- and right-handed. Many claim that left-handed individuals are more creative than their right-handed counterpart.
In spite of conflicting results Professor Hartwig Siebner believes in the theory of left-handed being more creative as they are raised in a world of right-handed individuals; “All buildings, doors, musical instrument and most cars are fitted for right-handed. Left-handed are challenged in every way and forced to find solutions to their problems”.
Are left-handed simply born more creative?
It is a possibility that left-handed individuals are simply born with a more creative brain than right-handed counterparts. However, no research has yet been able to verify this theory. Answering the question is not easy as it would demand including 1-2 year old children in the studies.
Professor Hartwig Siebner explains that most studies on the creativity of right- and left-handed individuals are based on the hypothesis that the right cerebral hemisphere is most creative. The right cerebral hemisphere is controlling the left side of the body and left cerebral hemisphere is controlling the right side. Hence as left-handed uses the right cerebral hemisphere they are more creative.
However, Professor Hartwig Siebner elaborates that a meta-analysis from 2010 did not find evidence for the hypothesis.
The full Danish article can be found here.