Science: Crack the mystery of "face blindness"!

I don’t know if you have encountered such a scene.
When you are walking on the street, a person with a very familiar face comes to you.
It is not until you pass by that you remember that TA was your former classmate, or someone you once knew.
People who are not only annoyed that they didn't say hello just now
.

Of course, for people who are blind, there is no such annoyance

But humans seem to have a special facial recognition memory.
Even if you forget TA’s name sometimes, you still remember the familiar face
.

Unfortunately, for a long time, scientists have not found brain regions or nerve cells related to facial memory

On July 1, 2021, researchers from Rockefeller University in the United States published a research paper titled: A fast link between face perception and memory in the temporal pole in the Science journal
.

This new study reveals the mechanism of human face recognition: There are a class of neurons in the temporal poles of the brain that can link face perception with long-term memory
.

This not only explains for the first time how our brain remembers the faces of people we are familiar with, but also has positive clinical significance for people with facial agnosia or facial blindness!

For a long time, scientists have been looking for a brain cell that can explain that when we see a very familiar face, such as our grandmother, we can immediately recognize it
.

Therefore, this assumption is also present in brain cells has been dubbed the "grandmother neuron"

In fact, the concept of "grandmother neuron" first appeared in the 1960s.
Scientists believe that it can encode a specific and complex concept on its own, and it corresponds to a human face one-to-one
.

For example, one neuron is used to remember the grandmother, and another neuron is used to remember the mother

Since then, scientists have discovered a large number of sensory neurons that specialize in processing facial information, as well as a large number of memory cells that specialize in storing personal contact data
.

However, "grandmother neurons"—special cells that connect vision and memory—have been undiscovered

The corresponding author of this study and Professor of Neuroscience and Behavior at Rockefeller University, Winrich Freiwald, said with a smile: “We sometimes even think that the hypothesis of'grandmother neurons' is impossible
.

When I first entered the field of neuroscience, if you want to laugh at someone From a human point of view, it is directly mocked as'just another grandmother neuron'

But now their research has confirmed that "grandmother neurons" do exist
.

He said: "Now, in an unknown corner of the brain that has not been fully studied, we have discovered the closest thing to the'grandmother neuron'-a type of nerve that can connect face perception and memory.

A region (red-yellow) of the temporal pole of the brain dedicated to recognizing familiar faces

An area of ​​the temporal pole of the brain (red-yellow) is dedicated to recognizing familiar faces An area of ​​the temporal pole of the brain (red-yellow) is dedicated to recognizing familiar faces

The research team discovered that a small area of ​​the temporal polar region (TP) of the brain may be involved in facial recognition
.

The research team did the following experiment in rhesus monkeys: When rhesus monkeys saw images of familiar faces (which they saw with their own eyes) and unfamiliar faces (which they just saw virtually on the screen), the researchers used Functional magnetic resonance imaging magnified the temporal poles of the brains of two rhesus monkeys and recorded the electrical signals of TP neurons

Nerve cells in the temporal region of the brain respond to familiar faces

Nerve cells in the temporal region of the brain respond to familiar faces .
Nerve cells in the temporal region of the brain respond to familiar faces.

The research team found that the neurons in the TP area are highly selective.
In rhesus monkeys, the specific performance is: after seeing the image, TP neurons can quickly distinguish between known and unknown faces, and respond less to familiar faces.
Familiar faces are stronger
.
After quantitatively comparing the specific data, the researchers found that TP neurons responded to familiar faces three times as much as unfamiliar faces! Although the subject actually saw unfamiliar faces on the screen many times
.

TP neurons respond to familiar faces but not to other familiar stimuli

TP neurons respond to familiar faces, but do not respond to other familiar stimuli TP neurons respond to familiar faces, but do not respond to other familiar stimuli

Dr.
Sofia Landi, the first author of this study, said: “This may indicate the importance of getting to know someone face-to-face
.
Nowadays, people’s lives are gradually virtualized on the Internet, so it is necessary to point out that the faces we see on the screen cause The intensity of nerve activity may not be as strong as seeing it in person
.
"

Not only that, this study also reveals that there is indeed a kind of "hybrid brain cells" in the human brain.
These brain cells not only have the function of sensory cells, have reliable and rapid responses to visual stimuli, but also act like memory cells.
, Only respond to stimuli that the brain has seen before
.

TP neurons encode identity information, simulating the psychophysics of facial recognition

TP neurons encode identity information, which simulates the psychophysics of facial recognition TP neurons encode identity information, which simulates the psychophysics of facial recognition

Of course, strictly speaking, the original definition of TP neuron and "grandmother neuron" is still slightly different
.
Among them, the most obvious difference is that TP neurons are not a cell that encodes a familiar face, they seem to work together as a collective
.

More importantly, the TP area is at the core of facial recognition.
This discovery means that researchers can quickly begin to study how these cells encode familiar faces
.
In the future, these findings may also have clinical significance for people with facial agnosia or facial blindness, which affects about 1% of the population
.

People with face blindness often feel depressed and powerless, because in the worst case, they can't even recognize their loved ones
.
Now, we can begin to explore the specific mechanisms by which the brain recognizes faces.
These findings will one day help us develop treatment strategies to help them
.

Original source:

Original source:

Sofia M.
Landi, et al.
A fast link between face perception and memory in the temporal pole.
Science 01 Jul 2021: eabi6671.
DOI: 10.
1126/science.
abi6671

A fast link between face perception and memory in the temporal pole.
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