Thanks for the great question!

The cerebellum (Latin for “little brain”) is an evolutionarily ancient brain area that exists in similar form in animals, fish, reptiles, and birds. You can find the cerebellum in the hindbrain, or towards the bottom of the back of the brain, near the brainstem. I have included an image of my own brain to this message, with the cerebellum highlighted in yellow (the picture is taken using a Magnetic Resonance Imager or MRI). Click on the link below to see My Cerebellum.

My Cerebellum

The structure of the cerebellum reflects its function. In the picture, notice how the cerebellum has very small, regularly spaced grooves. This very complex organization gives the cerebellum the ability to perform lots of calculations that enable fine motor control, or how we can precisely control our muscles to achieve certain goals.

The cerebellum does not initiate movement, as that is the job of the motor cortex, but it does make motions precise, coordinated, and correctly timed. It does this by processing signals from other parts of the brain and signals from all other parts of the body. By integrating all these signals, the cerebellum is able to produce the very controlled and careful muscle movements that allow us to write, play a musical instrument, or play a sport. Our sense of balance and how effortless we find walking are also functions of the cerebellum.

Damage to the cerebellum results in a loss of fine motor control, and relearning movements that were once effortless, like walking, can become incredible challenges without this specialized part of the brain.

The cerebellum is, among other things, the muscle coordination center of the brain. If you decide to do something with your muscles, the signal is processed in your cerebellum. This excludes involuntary muscle twitches like contact with something hot, which will go to a ganglion in your spinal column instead of ever reaching your brain, and activity of smooth muscle like the muscle lining your blood vessels and digestive tract.

The cerebellum is one of the oldest parts of the brain, meaning that it is one of the first sections to evolve. Because of this, it performs some of the most basic actions that an animal needs to survive. While we could live lives, although they would be very boring, without complex thought and logical reasoning, we could not survive without fine control of our motor functions. This is what the cerebellum does. It controls basic voluntary movements (posture, balance, and coordination) as well as speech.

Basically, any time you intentionally move muscles the cerebellum is working to coordinate it in a balanced manner. It is interesting to note that patients with damaged cerebellums are not paralyzed, rather they are slower to react, have difficulty balancing, and often experience muscle tremors. Any sort of complex movement becomes very unsteady for these patients. Thank you for your question!

I love this question! Thanks for asking.

The cerebellum is one of the most fascinating parts of the human brain. Actually, all vertebrates (animals with a spinal cord) have a cerebellum! That's because the cerebellum is a crucial part of the "hindbrain", one of the oldest parts of the brain. Today, humans have a hindbrain, a midbrain, and a forebrain. Scientists believe the hindbrain may have first evolved between 570 and 555 million years ago.

Okay, so it's old, and all animals with a spinal cord have it, but why do I think the cerebellum is so cool? That's because the function of the cerebellum is actually still being figured out... we still don't fully understand it! Luckily, we do know a few things about what the so-called "little brain" does. Let's find out what we do know.

The most well understood function of the cerebellum is to "fine-tune" movement. That means the cerebellum helps us move in a coordinated and precise manner, in terms of space and time. Imagine you wanted to reach for a glass of water on the table in front of you... the cerebellum would help you to move your hand smoothly, rapidly, and directly toward that glass of water. Helpful, huh? If you had cerebellar damage, your hand might move in a slow and erratic manner toward the glass, and you would need to correct the trajectory of your hand again and again.

It's important to remember that the cerebellum isn't the brain structure that decides how we're going to move, or to initiate movement, but it does help us fine-tune our movement to be coordinated and precise.

Over the last few decades, scientists are starting to think that the cerebellum actually does more than just fine-tune our movement. Now we don't have any definitive proof, but lots of different pieces of evidence from neuroscience research are telling us that the cerebellum might have a role in language, attention, emotion, affect, and even mental imagery!

More on that to come... in the future!
Thanks again for your question. Keep 'em coming!