“And this is the brain stem,” continued Skylar, pointing to a long skinny part sticking out of the back. It was painted yellow. “Our brain stems make sure that we are always breathing and our hearts are always beating,” Claire explained. “Imagine if you had to remember to do those things.”
from Magnificent Makers: Brain Trouble
written by Thane Griffith
illustrated by Reggie Brown
Random House Children’s Books, 2020
(audiobook accessed on Libby 7/18/26)
Sometimes when I was still working every day in my “real job” as a librarian, if I was overly busy, extra tired, or living through a period of overwhelm, sometimes it seemed I might have forgotten to load my brain into my head before I left the house. I’d be forgetful and felt disjointed, scattered.
Like most people my age, I think about thinking. I wonder how well my memory is working What was this morning’s Wordle? It’s Tuesday?! Again?! Did I forgot something at the grocery store yesterday? Important things like those.
Remember the TV ad for a brain-enhancing supplement for people? It’s supposed to help us think more clearly and stay focused on the task at hand. “It’s made from jellyfish,” says the voice-over in the ad.
But guess what? Jellyfish don’t have brains.
Research showed that apoaequorin, the jellyfish protein used in Prevagen, does not benefit the human brain. WebMD reported in a 2025 article that Quincy Bioscience, the company that marketed Prevagen, lost a false-advertising lawsuit in 2024, and had to stop claiming its benefits.
What got me curious was not the results of the lawsuit (though it’s too bad about all the people who were hoodwinked by truth-stretching or down-right lies). It was that impossible-sounding sentence “jellyfish don’t have brains.”
How does that even work?
In October 2023, the University of Sydney published an article called “Brainless organisms can learn—so what does it mean to think?” exploring that very question.
The main function and purpose of a brain is to synthesize new information, to learn. That some animals don’t have a brain led Tom White, Senior Lecturer and Fellow at U of Sydney, to re-think what it means to learn.
Learning can be functional or structural and measured by noting changes in behavior. My first degree was in education. I studied three different modes of learning.
visual: new information learned best when it is seen or read
auditory: new information is learned best when it is heard
kinesthetic: new information is learned best through physical activities
That was then, this is now and learning styles are divided differently, any where from those three to up to 15. Yikes.
Besides learning styles, learning theories abound from cause/effect or reward/punishment models like Pavlov’s dogs to the digital-age “theory of connectives” where people access new information by tapping into vast knowledge sources across databases, platforms, and human networks.
Learning is measured by assessing written tests, observing changes in behavior, noting progress toward proficiency in an area like reading or gymnastics.
We use our brains to learn, to wonder, to become proficient in a new skill, but our brains also take care of everything we don’t have to think about like heartbeats, breaths, eye-blinks. Also healing a stubbed toe or a black eye or a head cold.
And how about the jellyfish and all the other animals who don’t have a brain? How do they learn? and think? and adapt to new environmental conditions? And how do scientists know that learning has taken place?
Jellies don’t have a brain, but they do have nerves spread throughout their body. Scientists experimented on a box jellyfish by putting a picture of moving gray bars in front of its nerve clusters and pairing that with a mild shock. After several sessions, the jellyfish began to signal that it wanted to move away from the gray bars as soon as it detected them. In this way, scientists found out that jellyfish can learn to avoid something unpleasant. But they are still studying the how.
Other animals are also brainless, but not clueless.
Sand dollars have a nerve ring that functions as their central nervous system. It controls movement and bodily functions including digestion. Sand dollars use a vascular system that circulates seawater through various tubes inside their bodies. They don’t need a heart. They also don’t have a respiratory system. Or eyes.
Johnsons sea cucumbers don’t have a brain either. Their central nerve ring extends radial nerves and a nerve net within its skin to detect chemicals and touch. You can see a picture here. They are about 12 inches long.
Nerve nets of corals extend from their mouth to their tentacles and serve the same functions as other brainless creatures.
Sea stars can’t swim. They spend their time either on the bottom of the ocean or floating or washed up on the beach. Light-sensitive eyespots on the tips of their arms help sea stars find food. The nerve ring in its center (it doesn’t have a head) coordinates essential functions and relays impulses to its arms. Like sand dollars, they absorb nutrients from their water-based circulatory system. They don’t need brains or hearts.
Here’s something else to ponder. Octopuses have mini brains in each limb in addition to the main brain in their mantle (head). Are nine brains better than one? That’s a question for another day!
I’m reading The Calamity Club by Kathryn Stockett (Speigel & Grau, 2026). I’m not very far along so here’s the publisher’s statement: “—an epic testament to underestimated women who know that calamity can be the spark of new beginnings. Libby will automatically return my copy before I finish, so my take will come soon. Stay tuned.
Be curious! (and use your brain and your heart)
from Magnificent Makers: Brain Trouble
written by Thane Griffith
illustrated by Reggie Brown
Random House Children’s Books, 2020
(audiobook accessed on Libby 7/18/26)
Sometimes when I was still working every day in my “real job” as a librarian, if I was overly busy, extra tired, or living through a period of overwhelm, sometimes it seemed I might have forgotten to load my brain into my head before I left the house. I’d be forgetful and felt disjointed, scattered.
Like most people my age, I think about thinking. I wonder how well my memory is working What was this morning’s Wordle? It’s Tuesday?! Again?! Did I forgot something at the grocery store yesterday? Important things like those.
Remember the TV ad for a brain-enhancing supplement for people? It’s supposed to help us think more clearly and stay focused on the task at hand. “It’s made from jellyfish,” says the voice-over in the ad.
But guess what? Jellyfish don’t have brains.
Research showed that apoaequorin, the jellyfish protein used in Prevagen, does not benefit the human brain. WebMD reported in a 2025 article that Quincy Bioscience, the company that marketed Prevagen, lost a false-advertising lawsuit in 2024, and had to stop claiming its benefits.
What got me curious was not the results of the lawsuit (though it’s too bad about all the people who were hoodwinked by truth-stretching or down-right lies). It was that impossible-sounding sentence “jellyfish don’t have brains.”
How does that even work?
In October 2023, the University of Sydney published an article called “Brainless organisms can learn—so what does it mean to think?” exploring that very question.
The main function and purpose of a brain is to synthesize new information, to learn. That some animals don’t have a brain led Tom White, Senior Lecturer and Fellow at U of Sydney, to re-think what it means to learn.
Learning can be functional or structural and measured by noting changes in behavior. My first degree was in education. I studied three different modes of learning.
visual: new information learned best when it is seen or read
auditory: new information is learned best when it is heard
kinesthetic: new information is learned best through physical activities
That was then, this is now and learning styles are divided differently, any where from those three to up to 15. Yikes.
Besides learning styles, learning theories abound from cause/effect or reward/punishment models like Pavlov’s dogs to the digital-age “theory of connectives” where people access new information by tapping into vast knowledge sources across databases, platforms, and human networks.
Learning is measured by assessing written tests, observing changes in behavior, noting progress toward proficiency in an area like reading or gymnastics.
We use our brains to learn, to wonder, to become proficient in a new skill, but our brains also take care of everything we don’t have to think about like heartbeats, breaths, eye-blinks. Also healing a stubbed toe or a black eye or a head cold.
And how about the jellyfish and all the other animals who don’t have a brain? How do they learn? and think? and adapt to new environmental conditions? And how do scientists know that learning has taken place?
Jellies don’t have a brain, but they do have nerves spread throughout their body. Scientists experimented on a box jellyfish by putting a picture of moving gray bars in front of its nerve clusters and pairing that with a mild shock. After several sessions, the jellyfish began to signal that it wanted to move away from the gray bars as soon as it detected them. In this way, scientists found out that jellyfish can learn to avoid something unpleasant. But they are still studying the how.
Other animals are also brainless, but not clueless.
Sand dollars have a nerve ring that functions as their central nervous system. It controls movement and bodily functions including digestion. Sand dollars use a vascular system that circulates seawater through various tubes inside their bodies. They don’t need a heart. They also don’t have a respiratory system. Or eyes.
Johnsons sea cucumbers don’t have a brain either. Their central nerve ring extends radial nerves and a nerve net within its skin to detect chemicals and touch. You can see a picture here. They are about 12 inches long.
Nerve nets of corals extend from their mouth to their tentacles and serve the same functions as other brainless creatures.
Sea stars can’t swim. They spend their time either on the bottom of the ocean or floating or washed up on the beach. Light-sensitive eyespots on the tips of their arms help sea stars find food. The nerve ring in its center (it doesn’t have a head) coordinates essential functions and relays impulses to its arms. Like sand dollars, they absorb nutrients from their water-based circulatory system. They don’t need brains or hearts.
Here’s something else to ponder. Octopuses have mini brains in each limb in addition to the main brain in their mantle (head). Are nine brains better than one? That’s a question for another day!
I’m reading The Calamity Club by Kathryn Stockett (Speigel & Grau, 2026). I’m not very far along so here’s the publisher’s statement: “—an epic testament to underestimated women who know that calamity can be the spark of new beginnings. Libby will automatically return my copy before I finish, so my take will come soon. Stay tuned.
Be curious! (and use your brain and your heart)
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