With only half a brain left, the accuracy of people reading and seeing faces can reach 80% PNAS

Only half of the brain remains, people can still think, and it is still a relatively normal kind! (Don't be afraid, this article is not a horror)

A new study shows:

More than 80% of the time, people who have had their hemibrains removed can read correctly and are not face blind.

The team behind this study states:

The brain is surprisingly plastic, and it can adapt to great trauma by reconnecting.

Losing half of your brain is not the same as losing half of your function!

The relevant papers have been published in PNAS (Official Science Journal of the National Academy of Sciences), one of the four famous journals in the scientific community.

The accuracy rate of literacy recognition in semi-cerebral patients reached 80%

Through this experiment, they hope to clarify two questions:

• Can a patient with only one hemisphere develop properly recognize words and faces?

• Is there a clear difference between leaving the left brain or leaving the right brain?

(Here's a question: Do you think people with developed left or right brains are smarter?) The answer will be revealed in a moment)

First, they found 58 normal people (for comparison) and a special group of young people:

40 patients who underwent hemispherectomy in children. Their median age was 16.7 years.

In general, because hemispherectomy is so rare, scientists rarely have the opportunity to reach multiple suitable patients at once.

But because telemedicine services have become more widespread for some well-known reasons over the years, the team was able to find so many people at once, a number unprecedented in such research.

In order to distinguish which side of the brain the patient mainly retains, the researchers called the patient who left the left brain LH patients and those who left the right brain as RH patients.

Next, the researchers designed and conducted 2 sets of experiments.

Let's start with experiment one: participants look at many pairs of words and face images in the center of the field of view.

Each set of words has 2 words, and the two are exactly the same or only one letter apart; For example: "soup" and "soap", "tank" and "tack".

Similarly, each group of portraits is also 2, and the two are exactly the same or look not much different.

The words or portraits are played in groups, and one appears for 750 milliseconds, followed by another "flash."

The participants were then asked to say whether the portrait or word they had just seen was the same or different.

After the initial data collection, the researchers performed analyses such as generalized linear mixed-effects model (LMEM) fitting.

The results show that in terms of face and word recognition, the comprehensive performance of normal people is indeed better than that of patients.

However, the average accuracy difference between patients and normal people in these tasks does not exceed 10%, and the accuracy rate of patients has reached more than 80%.

In addition, there was no clear difference in discrimination accuracy between patients with LH and RH.

In order to more directly compare whether there are any functional differences between the single hemisphere of the patient's brain and the single hemisphere of the normal person's brain, the researchers also carried out experiment two.

The subjects still looked at these pairs of words and portraits, and the playback method was the same as above.

But this time, all normal people only use half their field of view to view words or portraits. They were blindfolded with one eye and observed with the other, half of whom used only their left eye and the others only their right.

Patients are allowed to see with both eyes.

After collecting the data, the researchers also performed generalized linear mixed-effects model (LMEM) fitting and other analyses.

The results showed that even if one eye was blindfolded, the accuracy of normal people in identifying faces was still higher than that of patients; However, in terms of word discrimination, there is not much difference between normal people who see with the right eye and patients.

And what about normal people who see with their left eye?

They performed better at word discrimination than people who saw with their right eye. However, when it comes to looking at the face, there is no significant difference between looking at the left or right eye.

Regarding the results of these new experiments, Dr. Marlene Behrmann, corresponding author of the paper and professor of psychology, is pleased to say:

This opened the door to studying human neuroplasticity, and now we can finally start studying the brain's ability to reorganize!

In the future, the team will continue to explore the functional upper limit of a single cerebral hemisphere.

About the research team & Easter eggs

The research team came from Pittsburgh University and Carnegie Mellon University.

The first author and corresponding author of the paper, Dr. Michael Granovetter, is also currently studying epilepsy and autism.

Another corresponding author, Marlene Behrmann, is now a professor of ophthalmology and psychology at the University of Pittsburgh and Carnegie Mellon University.

Finally, there is an Easter egg -

Let's answer the previous question: Actually... It is better to have developed brains on both sides.

Although there is a popular saying: people who are good at thinking with their left brain are more capable of mathematics and logic; People with developed right brains are more creative.

But numerous new studies have shown that when dealing with many tasks, the two sides of the brain are not so opposed, but work together.

Experiments have shown that the ability to do math is strongest when both hemispheres of the brain work at the same time.

Paper address: https://medicalxpress.com/news/2022-10-word-recognition-adequately-brain.html
reference link:

https://neurosciencenews.com/word-face-recognition-neuroplasticity-21725/