Strange to be introducing a new project on my conclusion post, but it’s a cool one!
While waiting for pea plant project parts to arrive, I revisited another project that Monica Gagliano had done with the Mimosa pudica: https://youtu.be/Xm5i53eiMkU?t=2m45s. For those of you too impatient to watch a video (like me!) the Mimosa pudica is a plant that is
“known for its leaf-folding behaviour in response to physical disturbance.” Basically, its leaves fold up and/or its stem falls when it receives a strong enough stimulus:
(For excellent background reading on the Mimosa pudica, go here.) Basically, the new kid on the block is shy, sensitive, bashful. But with some training, could they become less so? Can they habituate to a certain stimulus?
“Habitu-they can!” is what Monica Gagliano et al. said in their paper, “Experience teaches plants to learn faster and forget slower in environments where it matters.” She dropped some 56 mimosas 60x in a row, 7x a day, to see if they’d stop closing their leaves after a while, when they ‘learned’ the stimulus wasn’t harmful. She measured leaves before and after as the measurement of response.
Sofie, a high school intern with us, built this plant dropping machine and ran some pilot tests:
Unfortunately, we got banned from the closet to drop the plants. Last weekend, I dropped 12 plants in my apartment, 9 in the experimental group and 3 in the control group. 60 times, 7 times a day. 3,783 is the number of times I would take a plant and drop it.
- Drop control plants once, 8 hours apart.
- Drop experimental plants 60x at time 0, after 10 minutes, after 1 hour, after 2 hours, after 4 hours, and after 6 hours.
- Then give them a new stimulus: in our case …
Yes. We shake the plant. The idea behind this is that the leaves will close right up again because it’s a new stimulus.
- Finally, drop it 60 more times after 10 minutes (once the leaves have opened up). Since it’s a familiar stimulus that they have hopefully learned is not dangerous, we’d expect plants to open up again.
But as always, we need to compare it to a control. Putting all the data together, here is what we find:
Want to see Monica Gagliano’s results to compare? Of course you do.
There are several important differences between my data and Monica Gagliano’s data.
- Her control plants closed a lot more in that first drop.
- She noticed learning during the first 60 drops, meaning the leaves started opening up in the middle of the 5-10 minute period when they were being dropped. My plant students, not so smart. They peaked learning at 2 hours and then seemed to forget most of it quite quickly. Hmm… not so much different from my human students…
- Her plants showed a strong response to the dis-habituation stimulus. They really didn’t like Swift’s suggestion to Shake It Off. My plants seemed to treat being shaken the same as being dropped. (Monica Gagliano’s protocol was to put them on a 250rpm shaker for 5 seconds. 250 rpm:
Her data is statistically significant. Mine? To be determined….
Qualitatively, what I noticed was that the plants seemed to exhibit maximum learning at 2 hours. They seemed to habituate to the force of stimulus rather than what the stimulus was (explanation for similar response to dishabituation). Also, notice how high plants 1-3 are in my graph post dis-habituation (upper right corner of my graph)? That’s because I only dropped them once, instead of 60 times, much like the control. I should probably take that out for my poster, but I wanted to show you all.
Anyway, if the plant’s brain is in its roots, as Darwin proposed, who knew that dropping plants on their heads would help them learn?
I’ll leave it here, but I’d like to thanks some people for helping me carry out my projects. Couldn’t have done without them:
And of course, all the people at the BYB office: Zorica, who would take extra care for the plants and go out of her way to help us; Katie, who would always make space for me crowding her space at the 3D printer; John, for lending out his beloved tools; Caitlin, for being patient with my late blog posts; Will, for his awesome mustache; Sanja, for help with getting me reimbursed; Greg, for being captain of this fellowship experience!
So much more to share, and I’m still waiting on one more data result, but goodbye for now!
Hello! There has been some trial and error since my last update. I started my experiment with Monica Gagliano’s protocol (overly simplified!):
- Grow seedlings, 48 of them:
- Get them used to 8 hours of light, 16 hours dark (circadian rhythm):
- Train them under decision covers for 3 days:
- Test them
She had 48 of them. Unfortunately, each of those PVC pipes are $16 each:
PVC (above) x 48 = $768
Well, that’s not very practical for a classroom experiment.
So I tried my DIY version.
- Take a plant cell box:
- Make cardboard covers for each of those 48 cells
Fit the covers over the plant cell box:
Make fan/light circuits for them:
Hook them up:
Here is the schematic:
So in this way, 48 plants are being trained with two circuit boards.
That was in theory.
- Cardboard is way too flimsy to stay on the appropriate columns.
- The fans, 5V, to work with the LittleBits circuits, were way too weak.
Everything kept sliding around, falling apart, as I was supposed to be training them. I was Chi-Fu trying to keep soldiers in line when I needed to be Captain Shang.
They grew as straight as sticks, when I was looking for this result:
Plants that grew towards where I presented the fan last, towards the middle of each of the two rows.
The plants also were tall and spindly, meaning they had tried to get to the top as quickly as possible.
So back to the drawing board. We decided to do everything PROPERLY this time. Stick to the protocol. Exactly.
One problem I’d had was everything slipping all over the place so I bolted things down:
We’ll start with a small n of 4. I have another experiment design coming up, but you’ll have to wait until the last post for this and hopefully more exciting data!
Hi! I’m Jessica, a high school Biology/Anatomy&Physiology/Marine Biology/Forensics teacher in southern California.
I’m the only high school teacher in this summer Fellowship of the Brain but hopefully I’ll make a good enough impression so they’ll invite more teachers in the future… after all, we ARE the market.
The first week has been amazing. Besides feeling like I’m in college again, I’ve been able to get my hands on all the BYB toys a teacher could ever want. Except I was much more squeamish than I’d like to admit when trying to cyborg a cockroach….
I have a B.A. in Human Biology: International Health and Infectious Diseases (a mouthful, I know…) and a Master’s in Education, so all this “spike sorting-ISI-auto-correlation-FFT- breadboard” language — neuroscience/computer science/electrical engineering — has been over my head, but I love it! That’s why I’m here.
All of us have our own individual projects, and to be honest, I was not very excited about the one I was assigned to at first.
I’d never worked with plants before, and every plant I’ve tried to raise has gone quickly to the grave. But the more I read about plants, the more I’m falling in love with them. They’re gentle, life-giving, competitive, quiet, sensing living systems. They’re the kid in class you never notice until they floor you with their presentation. They’re the guy when, looking back, you should have totally gone for, not that show-off who, after a couple dates, you realize is completely actually boring. They’re the friends who are a nicer and nicer surprise the more you get to know them, not the terrible oh-no-what-have-I-gotten-into type of surprise. In sum, here’s a storyboard representation of my project:
So my project asks, can plants learn? Can they be “trained” to associate certain neutral cues with a reward like Pavlov’s dogs did? Monica Gagliano, the woman in the 5th panel above, did an astounding study published in one of the most bad-ass journals out there (Nature), which I’ll be recreating so that classrooms can try this for themselves!
I’ll be taking the Pisum sativum aka the pea plant:
Growing them in a pots and “train” them to associate fans with light (their food! how cool is that — plants eat light…) and then see if they grow towards the fan even when there is no light present.
Here is one of the figures of M. Gagliano’s paper here:
And some links on cool plant stuff:
https://youtu.be/_w7MHmebvrM: Monica Gagliano on Radiolab
https://youtu.be/yb_9X3I38N0: Sniffing Predatorial Parasitic Plant
https://youtu.be/pvBlSFVmoaw: Plant-to-Plant Communication
Next time I’ll get you an update on how I’ve set up my experiment 🙂