Study Finds You Can Still Recognize Names And Faces With Half A Brain
As someone with a whole brain but who still struggles with remembering names and faces, the results from this study seem a bit hard to believe – but it seems as if the organ that controls our thoughts, memories, and ability to speak and reason never runs out of surprises.
We know that the left and right hemispheres of the human brain process words and faces respectively, so it would seem to follow that, if one hemisphere was damaged or missing, that ability would disappear.
This results of this (unpublished) study suggest otherwise, claiming that the brain’s plasticity allows it to rewire itself to tackle both tasks in a single hemisphere.
Researchers came to this conclusion after studying 40 adult volunteers who had undergone hemispherectomy surgery as children. These procedures are extreme and always a last resort, typically to cure a child of debilitating seizures that originate in just one half of their brain.
Participants were shown colorless face or a four-letter word for less than a second, and afterward were presented with another word or face for 150 milliseconds.
When asked to determine whether or not the two words/faces were the same or different, accuracy among the hemispherectomy patients was greater than 80% for both face and word recognition.
The accuracy rate was not changed regardless of which hemisphere the participant was missing.
A second experiment verified that, although the control group (who retained their entire brain) did perform slightly better at recognizing both words and faces…unless the words were displayed on just the left side of the viewing screen.
If the words or images flashed on the left side, the control group fared only as well as the hemispherectomy patients, again regardless of which half of their brain was missing.
The researchers released a statement that shows their excitement about what this could mean for the brain’s plasticity.
“Altogether, the findings indicate that a single developing hemisphere, either left or right, may be sufficiently plastic for comparable representation of faces and words. This demonstrates the remarkable plasticity of the developing brain.”
Another study seems to suggest that the degree of plasticity depends on a person’s age, as adults who suffer injuries to one side of the brain or the other tend to lose their ability recognize either words or faces.
Those results found adults with damage to their left hemisphere took 100 times longer to read words than healthy controls, and those with damage to the right side made 10x as many mistakes recognizing faces.
When the surgery removing half of the brain was performed when the participant was a child, however, “the preserved hemisphere…supports both face and word recognition.”
All of this is not to say that quality of life will be exactly the same as someone with an entire brain, or that those who undergo hemispherectomies as children will confront no additional challenges, but it does point to the fact that the developing brain is a force to be reckoned with indeed.
Tags: · brain plasticity, hemispherectomy, people with half a brain will re-wire to work with one hemisphere, top