Do we have a dominant hemisphere in the brain? Is a particular hemisphere responsible for your creativity or logical ability? How relevant is being left or right-handed to our ability to think logically or imaginatively?
Many of us will have heard the idea that the left hemisphere of the brain is responsible for analytical thinking while the right side of the brain deals in all things creative. This notion is often extended to people referring to themselves or others as being ‘left-brained’ or ‘right-brained’. The assumption is, depending on which hemisphere is dominant for you, that you will either lean toward the creative or logical, and further, in order to tap into either ability, you need to ‘engage’ a particular half part of your brain. The combination of associating specific abilities with a side of the brain has also been linked to an interpretation of ‘handedness’. This is the idea that whether you’re right or left-handed will determine how creative or analytical you are. Left-handed people are often associated with being more creative while their right-handed counterparts are seen as more analytical.
Like all good myths, this is based on an element of truth. Most notably being, that to a degree the hemispheres and regions of our brains are responsible for specific functions. For example, one hemisphere of your brain does control the opposite side of your body. Specifically, the left hemisphere of your brain controls the right side of your body, and what you see with your left eye is projected into the right side of your cerebral cortex (and vice versa).
There are a few challenges to this understanding of handedness being associated with particular predispositions, not least of all being that while you will most likely have a dominant hand and hemisphere, they may not necessarily align. Generally speaking, if you’re right-handed, the left hemisphere of your brain will be your dominant side, however if you’re left-handed, there is only around a 20% chance of your right hemisphere being dominant.
Another broader problem with the idea of being ‘left-brained’ and ‘right-brained’ is that while we can isolate certain functions to specific areas of the brain, overwhelmingly the hemispheres in our brains and the regions within them do not work in isolation of one another.
Neuro-imaging has allowed neuroscientists to map the wiring structure of the brain and this has shown that our brains are incredibly complex and interconnected. Typically, the wiring of the left hemisphere is concentrated within specific pockets or regions with fewer connections between them, and the right hemisphere of the brain is wired more holistically so that the connections link the hemisphere as a whole. While the hemispheres of the brain are wired differently, neuro-imaging has shown that there are many instances in which it is faster for electrical impulses to travel from one hemisphere to another than across a single hemisphere and that when our brains are engaged in the complex thought necessary for analytical thinking or creativity, the brain is operating as a whole.
Another key challenge to the theory is that while there is certain activity that does typically occur in one hemisphere or region of the brain, this is not fixed. A great demonstration of this is the recovery of hemispherectomy patients. A hemispherectomy is a medical procedure in which one half of the brain is removed. Based on the wisdom of being ‘left-brained’ or ‘right brained’, removing one half of the brain should result in the loss of the activities and abilities associated with that hemisphere. Interestingly, the study of hemispherectomy patients has demonstrated that this is not the case. In many instances in which young patients have undergone this treatment, the remaining hemisphere of the brain has compensated for the lost hemisphere and rewired itself to take on the functions that typically occurred in the missing hemisphere. This is known as neuroplasticity, the ability of brains to change and adapt. Based on this understanding of neuroplasticity, it’s problematic to definitively assign certain activity or abilities solely to one side of the brain.
By understanding how our brains work and how they are inextricably connected and able to change, it is clear that something as complex as creativity or logical analysis cannot be attributed to a single hemisphere in the brain. While strategies that purport to assist in harnessing a specific portion of the brain may help us access certain abilities, this is likely due to a simple placebo effect. If these strategies work for you, there’s certainly no harm in it. At the Langley Group we advocate treating yourself like a scientific experiment and testing research on yourself. If something works for you, great, and if it doesn’t, try something else!