I've heard that the left brain controls the logical aspects of the thought and right brain controls the creative. Is there any truth to such claims?
In the case of Left Brain/Right Brain "function" has been interpreted as "thought." Thought and function are not the same thing.
Each hemisphere of the brain has specializations or function sets. Generally:
- Right hemisphere: Processing of visual and audiological stimuli, spatial manipulation.
- Left hemisphere: Linear reasoning and language functions.
How do we know?
... definite evidence for language lateralisation arose from studies in split brain patients. In these patients, the nerve fibres that connect the two hemispheres were severed in order to stop the spread of epileptic seizures from one hemisphere to the other ... studies of these split brain patients were carried out in the 1960s and 1970s by the Nobel Prize laureate Roger Sperry and his colleagues at the Californian Institute of Technology ... Sperry’s experiments yielded an amazing result: when split brain patients processed an object with their right hand, i.e. with their left hemisphere, they could easily name the object. In contrast, when an object was touched with the left hand, i.e. processed by the right hemisphere, they could not name it!
The whole "philosophy" of Left Brain/Right Brain was pulled from this information, not from further research. In other words, it's made up.
The notion of different hemispheric thinking styles is based on an erroneous premise: each brain hemisphere is specialised and therefore each must function independently with a different thinking style. This connection is a bridge too far: it uses scientific findings regarding functional asymmetries for the processing of stimuli to create conceptions about hemispheric differences on a different level, such as a cognitive thinking style. Furthermore, there is no direct scientific evidence supporting the idea that different thinking styles lie within each hemisphere. Indeed, deriving different hemispheric thinking styles from functional asymmetries is quite a bold venture, which oversimplifies and misinterprets scientific findings.
The above two quotes come from The left brain/ right brain myth.
Being a neurophysiologist, I suppose I ought to feel that progress has been made: in no other age could it have taken a mere twenty years to shift from a predominantly religious metaphor to a semi-scientific one. But the neurophysiologists and neuropsychologists who specialize in the human cerebral cortex are starting to view the left-righters with something of the wariness which the astronomers reserve for astrology." -William Calvin
Is it reversed for anyone? Left-handers? Situs inversus?– endolithMar 4, 2011 at 18:58
3@endolith: Are you asking if lateralisation of specific functions is reversed for anyone? If so, the answer is yes. In 95% of right-handers language is lateralised to the left-hemisphere, while for left-handers its 70%, with 15% lateralised to the right, and 15% bilateral. That and more data here: dx.doi.org/10.1007/s11065-006-9011-9 Mar 13, 2011 at 8:48
Incidentally, for anyone interested, that link I posted is a review of the language functions that the right hemisphere contributes. Mar 13, 2011 at 8:51
@Solus: Mentioned in this video, too. youtube.com/watch?v=sBbilBZ46Eg– endolithOct 22, 2011 at 20:01