Letting pigs blink and snooze proves the effectiveness of the brain test

If you have ever seen an ophthalmologist, it is very likely that you have felt that the sudden air ejection into your eyes constitutes a traditional glaucoma examination

Scientists use similar methods to test the learning and memory abilities of animals and humans

Although the blink test started in 1922, it has never been tried on pigs until now

"Our idea is that if we can improve the structural development of the brain through nutritional interventions, we should use fewer experiments to understand this law

Dilger specializes in the effects of nutrition on the developing brain, and most of his work goes directly to the infant formula industry

Dilger's team usually uses magnetic resonance imaging (MRI) to study the response of pig brains to new components.

But Dilger wanted a tool to specifically assess the cognitive processes of the cerebellum

"For humans and mice, we use completely different systems for eye blink adjustment," Boele said

"We tried cameras, diodes and all kinds of things to capture blinks

The solution is to stick a small section of trachea next to one eye, and stick magnetic sensors on the forehead and eyelids to record blinking

Yes, Boele puffed smoke into his eyes to test the system

In order to ensure that the heads of these pigs can move freely, but not stand up and run around, the researchers placed them in a custom-made silencer box equipped with a pig-sized hammock

Obviously the piglets are very comfortable

Sangyun Joung, a doctoral student in the Illinois Neuroscience Program and co-author of the study, said: “Each pig has been trained for five days to get them accustomed to a hammock and test environment

Once the pig gets used to this setting, the real work begins

The researchers repeated each set of eight tests five times over five consecutive days

"It's not just intermittent, once a second," Dilger said
.
"This system will wait until the eyes in a stable position, then repeat the test at random times, so that pigs can not be expected to blow occurred
.
"
.

But during the five-day experiment, they did learn to predict the smoke mass
.
Soon, in the eighth test, the pig was closing its eyes at a speed of 500 milliseconds—a light but not blowing
.

"The timing is good
.
If you observe the eyelid response of conditioned reflex, you will find that the eyelid is completely closed at the moment of exhalation.
There is only perfect motor timing, accurate to the millisecond
.
It's so beautiful
.
"

The research team also learned something about pigs they didn't know before
.

"We know that pigs can only close one eye at a time; they blink
.
"In fact, we are not sure about this," Dilger said
.
"But because they are pigs, they are smart and patient all day long.
Don't let you succeed
.
Some pigs will only lie there with one eye closed, which means we cannot test them
.
"

The blink test specifically targets the activity of the cerebellum, which is the part of the brain responsible for making quick, unconscious predictions
.
These predictions are related to motor responses, such as where you should go when you walk; and cognitive processes, such as predicting what someone will say next in a conversation
.

The cerebellum has been constantly making short-term predictions
.
Interaction with our environment is essential
.
When we think of learning and memory, we often think of very complex cognitive problems, but most of our daily behaviors are just smooth and automatic interactions with our environment.
In blinking adjustment, your cerebellum is basically You solved the problem
.
You don't have to think about it
.
It is making this short-term forecast, and this is what we are studying
.
"

The cerebellum of pigs is more developed than human babies at birth
.
This can be clearly seen in Boele's blink conditioned reflex tests on babies 6 to 8 months old; human babies usually cannot learn this task at that age
.

Unlike humans, pigs need to be able to make motion and cognitive predictions immediately, because they can get up and walk around a few minutes after birth
.
When Dilger used MRI to study the porcine cerebellum, he focused on the structure.
He usually didn't see too many changes brought about by nutritional intervention
.
This is because the cerebellum of pigs is more developed at birth, which makes them a precocious species
.
But changes in nutrition may change the function of brain regions
.
This is what the blink test will tell him in the future
.

Usually, functions follow structure, but not always
.
He said: "Nutrition deficiency may lead to defects in blink conditioning, which is an associative learning task
.
We hope to use nutritional intervention as a relatively non-invasive way to understand the development of the cerebellum
.
"
Young Domestic Pigs (Sus scrofa) Can Perform Pavlovian Eyeblink Conditioning