Fruit flies play VR and appear in Nature, and it is found that they have attention mechanism and working memory. It turns out that the brain of insects is not much worse than that of mammals.

Posted early from Aofei Temple
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Can you imagine fruit flies having attention, working memory, and something like consciousness?

Almost catching up with mammals.

In a study that just appeared in Nature, researchers created a special VR device for fruit flies.

In this 360-degree panoramic environment, the fruit fly is tied with a rope but can flap its wings freely, and its movements will update the scene in real time, creating the illusion of flying freely.

It was in such experiments that researchers made new discoveries, observing cognitive abilities that are usually observed in mammals:

The tiny brains of fruit flies are capable of advanced cognitive abilities such as memory formation, fading, and "distraction."

What's going on? Are insects and mammals so different? Let's find out.

Pavlov's fruit fly

This experiment on fruit flies followed the famous classical conditioning experiment in psychology: Pavlov's dog.

In the scene of feeding the dog, at first the dog would drool as soon as the owner came to feed it. Then Pavlov rang a bell before each feeding, and later the dog would drool when it heard the bell.

During this process, the dog associated food (unconditioned stimulus, US) with the bell (conditioned stimulus, CS) .

The same principle applies to the experiment on fruit flies, except that feeding is replaced by "burning with a laser" and ringing the bell is replaced by "looking at a T-shaped pattern."

When there is a positive "T" shaped pattern in the fruit fly's field of vision, it will also be burned at the same time, but not vice versa. After 7 times of training, when a positive "T" and an inverted "T" appear in the field of vision at the same time, the fruit fly will "fly" to the inverted "T".

This "flight" direction is determined by a high-speed camera based on the angle at which the fruit fly vibrates its wings:

Distracted fruit flies

After the fruit fly had associated the pattern with the hot stimulus, its memory could be tested.

For example, we can present a pattern first, and then turn on the laser to heat it 5-20 seconds after the pattern disappears.

After repeating this several times, if the laser is not turned on, the fruit fly can still respond after 5-20 seconds, which means that traces of the visual stimulation are retained in the fruit fly's brain.

In order to determine how long the fruit flies' memory can be retained, the researchers also designed interference elements to "distract" the fruit flies: blowing a soft air at the fruit flies at different time periods after the pattern disappeared.

The results showed that compared with the situation without disturbed airflow (white bars) , the performance index of fruit flies decreased faster in the situation with disturbed airflow (gray bars) , and basically returned to zero after 40 seconds.

This shows that pattern stimulation can leave short-term memory in the fruit fly's brain, and interference factors can "distract" the fruit fly, which means that there is an attention mechanism.

In addition, the researchers also monitored the activity of the fruit fly brain during this process and found that the formation and extinction of memory were related to the activity of R2 and R4m neurons:

This part of neurons is located in the ellipsoid part of the central complex of the fruit fly, which corresponds to the cerebral cortex area in the human brain:

这么看来，果蝇和哺乳动物的认知能力之间的联系还是很显著的。今后说不准还可以把果蝇作为高级认知功能的模型。

This connection becomes even more profound when you consider that insects and mammals evolved from a common ancestor.

Ralph Greenspan, a professor of biological sciences at the University of California, San Diego, also said that the correspondence between brain regions of fruit flies and mammals can be mapped based on molecular characteristics and memory storage methods, gradually revealing how humans achieve cognitive functions.

Reference Links:

[1]https://ucsdnews.ucsd.edu/pressrelease/flies-possess-more-sophisticated-cognitive-abilities-than-previously-known
[2]https://www.nature.com/articles/s41586-022-04433-6#data-availability