Minds Everywhere.
The planarian is a flatworm shaped like a comma.
It can be found wiggling through the muck of lakes and ponds worldwide.
Its pin sized head has a microscopic structure that passes for a brain.
It aspires to nothing more than life as a bottom-feeder.
But the worm has mastered one task that has eluded humanities greatest minds:
Regeneration.
Tear it in half, and the head will grow a new tail, while its tail will grow a new head.
After a week two healthy worms swim away.
Growing a new tail is a neat trick.
It is the tail’s end that intrigues biologist Michael Levin.
He studies the way that bodies develop from single cells, among other things.
His research led him to suspect that the intelligence of living things,
lies outside the brains to a surprising degree.
Substantial smarts may be in the cells of a worm’s rear end, for instance.
All intelligence is really collective intelligence, because every cognitive system,
is made of some kind of parts.
An animal that can survive the complete loss of its head was Levin’s perfect test subject.
In their natural state planaria prefer the smooth and sheltered, to the rough and open.
Put them in a dish with a corrugated bottom, and they will huddle against the rim.
Levin trained some planarian to expect edible treats in the middle of a ridged dish.
They soon lost all fear of the rough patch, eagerly crossing the divide to get the treats.
He trained the other worms in the same way in smooth dishes.
Then he decapitated all of them.
He discarded the head ends, and waited two weeks while the tail ends regrew new heads.
He then placed the regenerated worms in corrugated dishes,
and dripped treats into the centre.
Worms that have lived in a smooth dish in their previous incarnation were reluctant to move.
But worms regenerated from tails that have lived in rough dishes,
learnt to go for the food more quickly.
Somehow despite the loss of their brains,
these planaria had retained the memory of the treat.
But how? where?.
It turns out that regular cells - not just highly specialised brain cells such as neurons -
have the ability to store information and act on it.
Levin showed that the cells do so by using subtle changes in the electric field,
as a type of memory.
These revelations have put him at the vanguard of a new field called basal cognition.
Scientists in this burgeoning area have spotted hallmarks of intelligence - learning,
memory, problem solving, outside brains as well as within them.
Until recently, most scientists held that true cognition arrived with the first brains,
half a billion years ago.
Without intricate cluster of neurons, behaviour was merely a kind of reflex.
But Levin and several other scientists believe otherwise.
He doesn’t deny that brains are awesome, paragons of computational speed and power.
But he sees the differences between cell clumps and brains as ones of degree,
not kind.
In fact Levin suspects that cognition probably evolved as cells started to collaborate,
to carry out the incredible difficult task of building complex organisms,
and then got souped-up into brains, to allow animals to move and think faster.
Brains were one of the most recent inventions of mother nature, the thing that came last, according to scientists.
These scientists hope to build deeply intelligent machines from the bottom.
It’s clear that the body matters, and then some how you add neural cognition on top.
In recent years interest in basal cognition has exploded.
Scientists have recognised many examples of surprisingly sophisticated intelligence,
at work across life’s kingdoms, no brain required.
For artificial intelligence scientists, basal cognition offers an escape from the trap,
of assuming that future intelligence must mimic the brain-centric human model.
For medical scientists, there are tantalising hints of ways to awaken cells’ innate powers,
of healing and regeneration.
For the philosophically minded, basal cognition casts the world in a sparkling new light.
Maybe thinking builds up from a simple start.
Maybe it is happening all around us, every day, in forms we haven’t recognised,
because we didn’t know what to look for.
Maybe minds are everywhere.
A few decades ago many scientists believe that non human animals couldn’t experience,
pain on other emotions.
Thinking was out of the question.
The mind was the purview of humans.
Now scientists recognise that people are just another animal species.
It was thought the real cognition set human beings apart.
Now that notion is in retreat.
Scientists are documenting the rich inner lives of creatures increasingly distant from us.
Apes, dogs, dolphins, crows and even insects are proving more savvy than suspected.
Scientists have shown that bees can use sign language, recognise individual human faces,
and remember and convey the locations of far flung flowers.
They have good moods and bad.
They can be traumatised by near death experiences.
These of course have actual brains.
The bigger challenge comes from evidence of surprisingly sophisticated behaviour,
in our brainless relatives.
The neuron is not a miracle cell.
It is a normal cell that is able to produce an electric signal.
In plants almost every cell is able to do that.
On one planet, the touch-me-not, featherly leaves normally fold and wilt when touched.
It is a defence mechanism against being eaten.
Scientists conditioned the plant by jostling it throughout the day, without harming it.
It quickly learnt to ignore the stimulus.
Most remarkably, when the scientists left the plant alone for a month, and then retested it,
it remembered the experience.
Other plants have other abilities.
A Venus flytrap can count.
It shuts only two of the sensory hairs on its trap are tripped in quick succession.
It pours digestive juices into the closed trap, only if its sensory hairs,
are tripped 3 more times.
These responses in plants are mediated by electric signals, just as they are in animals.
Wire a flytrap to a touch-me-not, and you can make the entire touch-me-not collapse,
by touching the sensory hair on the flytrap.
And these and other plants can be knocked out by anaesthetic gas.
Their electric activity flatlines, and they stop responding as if unconscious.
Plants can sense their surroundings surprisingly well.
They know whether they are being shaded by part or themselves or something else.
They can detect the sound of running water, and grow towards it.
They can detect the sound of bees wings, and produce nectar in preparation.
They know when they are being eaten by bugs and will produce nasty defence chemicals,
in response.
They even know when their neighbours are under attack.
Scientists played a recording of munching caterpillars to a cress plant,
that was enough for the plant to set a surge of mustard oil into its leaves.
Plants seem to know exactly what form they have and plan their future growth,
based on the sights, sounds, and smells around them.
They make complicated decisions about where future resources and dangers,
might be located.
They do it in ways that can’t be boiled down to simple formulas.
Plants plan ahead to achieve goals.
They integrate vast pools of data.
They need to engage with their surroundings adaptively and proactively.
Non of these implies that plants are geniuses.
But within the limited tool set, they show a solid ability to perceive their world.
They use that information to get what they need - key components of intelligence.
Plants are relatively easy case - no brains but lots of complexity,
and trillions of cells to play with.
That is not the situation for single celled organisms.
These are traditionally relegated to the mindless category.
If amoeba can think, then humans need to rethink all kinds of assumptions.
The evidence for cogitating pond scum grows daily.
Consider the slime mould,
a cellular puddle that oozes through the world’s forests digesting dead plant matter.
Although it can be the size of a throw rug, a slime mould is one single cell with many nuclei.
It has no nervous system, yet it is an excellent problem solver.
Scientists placed a slime mould at one end of a maze, and pile of oat flakes at the other.
The slime mould did what slime moulds do,
exploring every possible option for tasty resources.
But once it found the oat flakes, it retreated from all the dead ends,
and concentrated its body on the path that led to the oats,
choosing the shortest route through the maze every time.
Scientists then piled oat flakes around the slime mould in positions and quantities,
meant to represent the population structure of Tokyo.
The slime mould contorted itself into a very passible map of the Tokyo subway system.
Such problem solving could be dismissed as simple algorithms,
but other experiments make it clear that slime moulds can learn.
Scientists placed dishes of oat meal on the far end of a bridge lined with caffeine,
which slime moulds find disgusting.
These slime moulds were stymied for days, searching for a way across the bridge.
Eventually they got so hungry, they went for it, crossing over the caffeine,
and feasting on the oat meal.
Soon they lost all aversion to the formerly distasteful caffeine.
They had over come their inhibitions, and learned from the experience.
They retained the memory even after being put into a state of suspended animation,
for a year.
This brings us back to the decapitated planaria.
How can something without a brain remember anything?
Where is the memory stored?
Where is its mind?
The orthodox view of memory is that it is stored as a stable network of synaptic connections,
among neurons in the brain.
This view is cracking.
Scientists were able to transfer a memory of an electric shock from one sea slug to another,
extracting RNA from the brains of shocked slugs, and injecting it into the brains of new slugs.
The recipients then “remembered” to recoil from the touch that preceded the shock.
If RNA can be a medium of memory storage, any cell might have the ability,
not just neurons.
There is no shortage of possible mechanisms by which collections of cells,
might be able to incorporate experience.
All cells have lots of adjustable pieces in their cytoskeletons, and gene regulatory networks,
that can be set in different confirmations, and can inform behaviour later on.
In the case of decapitated planaria, scientists speculated that the remaining bodies,
were storing information, in their cellular interiors,
that could be communicated to the rest of the body, as it was rebuilt.
Levin thinks that something even more intriguing is going on.
Perhaps the impression was told not just within the cells,
but in their states of interaction through bio electricity,
the subtle current that courses through all living beings.
Levin has been studying how cell collectives communicate,
to solve sophisticated challenges during morphogenesis, or body building.
How do they work together to make limbs and organs in the right place?.
Part of that answer seems to lie in bio-electricity.
The fact that bodies have electricity flickering through them has been known for centuries.
But till recently scientists thought they were mostly used to deliver signals.
If you pass some current through a frog’s nervous system, the frog’s leg kicks.
Neurons used bio-electricity to transmit information.
But most scientists believed that was a speciality of brains, not bodies.
Since the 1930’s a small number of scientists, have observed that other types of cells,
seem to be using bio-electricity to store and share information.
Levin immersed himself in this unconventional body of work,
and made the next cognitive leap, drawing on his background in computer science.
He had supported himself during school by writing code.
He knew that computers used electricity to toggle their transistors between 0 and 1,
and that all computer programs were built from the binary foundation.
As an undergraduate he learnt that all cells in the body,
have channels in their membrane that act as voltage gates,
allowing different levels of current to pass through them.
He immediately saw that such gates could find function like transistors,
and that cells could use electricity driven information processing,
to co-ordinate their activities.
To find out whether voltage changes really altered the ways,
that cells passed information to one another, Levin turned to his planaria form.
He designed a way to measure the voltage at any point on a planarian,
and found different voltages on the head and tail ends.
When he used drugs to change the voltage of the tail to that normally found in the head,
the worm was unfazed.
But then he cut the planarian in two.
Now the head end regrew a second head instead of a tail.
Remarkably when Levin cut the new worm in half, both heads grew new heads.
Although the worms were genetically identical to normal planaria,
the one time change in voltage resulted in a permanent two headed state.
For more confirmation that bio-electricity could control body shape and growth,
Levin used the African clawed frogs.
It is the common lab animal that quickly metamorphose from egg to tadpole to adult.
He found that he could trigger the creation of a working eye anywhere on a tadpole,
by inducing a particular voltage in that spot.
By simply applying the right bio-electric signature to a wound for 24 hours,
he could induce regeneration of a functional leg.
The cells took it from there.
It was like a subroutine call.
In computer programming, a subroutine call is a piece of code,
that tells the machine to initiate a whole suite of lower level mechanical actions.
The beauty of this higher level of programming is that it allows you to control,
billions of circuits, without having to open up the machine,
and mechanically alter each one by hand.
And that was the case with building tadpole eyes.
No one had to micromanage the construction of lenses, retinas, and all other parts of an eye.
It could all be controlled at the level of bio-electricity.
It is literally the cognitive glue.
It allows groups of cells to work together.
This discovery could have profound implications for our understanding,
of the evolution of cognition, and also for human medicine.
Learning to co-ordinate cells’ behaviour through bio-electricity might help treat cancer.
Cancer is a disease that occurs when part of the body stops co-operating,
with the rest of the body.
Normal cells are programmed to function as part of the collective.
They stick to the tasks assigned - liver cell, skin cell, etc,.
But cancer cells stop doing their job and begin treating the surrounding body,
like an unfamiliar environment.
They strike out on their own to seek nourishment, replicate,
and defend themselves from attack.
In other words they act like independent organisms.
They loose their group identity,
partly because the mechanism that maintain the cellular meld can fail.
Stress, chemicals, genetic mutations can all cause a breakdown of this communication.
Scientists have been able to induce tumours in frogs,
by forcing a bad bio-electric pattern on to healthy tissue.
It is as if the cancer cells stop receiving their orders and go rogue.
Even more tantalisingly, Levin has dissipated tumours by reintroducing,
the proper bio-electric pattern, in effect reestablishing communication,
between the breakaway cancer cells and the body.
At some point in the future bio-electric therapy might be applied to human cancers,
stopping tumours from growing.
It could also play a role in regenerating failing organs like kidneys, or hearts,
provided scientists can crack the bio-electric code that tells cells,
to start growing in the right patterns.
With tadpoles, Levin showed that animals suffering from massive brain damage at birth,
were able to build normal brains after the right shot of bio-electricity.
Levin’s research has always had tangible applications, such as cancer therapy,
limb regeneration, and wound healing.
Recently he has allowed a philosophical current to enter his papers and talks.
In a 2019 paper, he argued that we are all collective intelligences built out of smaller,
highly competent problem solving agents.
What we are is intelligent machines, made of intelligent machines,
made of intelligent machines, all the way down.
This realisation came in part to Levin from watching the bodies of clawed frogs,
as they developed.
In frogs’ transformation from tadpole to adult, their faces undergo massive remodelling.
The head changes shape, and the eyes, mouth and nostrils migrate to new positions.
The common assumption has been that these rearrangements are hardwired,
and follow simple mechanical algorithms carried out by genes.
Levin suspected it wasn’t so preordained.
He electrically scrambled the normal development of frog embryos,
to create tadpoles with eyes, nostrils and mouths in all the wrong places.
Levin called them Picasso tadpoles.
If the remodelling was preprogrammed, the final frog face should have been,
as messed up as the tadpole.
Nothing in the frogs evolutionary past gave its genes for dealing with such a novel situation.
Amazingly the eyes and mouths found their way to the right arrangement,
while the tadpoles morphed into frogs.
The cells had an abstract goal and worked together to achieve it.
This is intelligence in action.
It is the ability to reach a particular goal,
by undertaking new steps in the face of changing circumstances.
Some of the most intense interest in Levin’s work has come,
from the fields of artificial intelligence in robotics, with see in basal cognition,
a way to address some core weaknesses.
For all the remarkable prowess in manipulating language or playing games,
AIs still struggle to understand the physical world.
They can churn out sonnets in the style of Shakespeare, but ask them how to walk,
and their clueless.
AIs in a sense, are too heady.
They tend to be around things like common sense and cause some effect.
This points to why you need a body.
If you have a body, you can learn about cause and effect, because you can cause effects.
Some scientists are at the vanguard of the “embodied cognition” movement.
It seeks to design robots that learn from the world by monitoring,
the way their form interacts with it.
An example of embodied cognition is a one and half year old child,
who is probably destroying the kitchen.
Toddlers poke the world, literally and metaphorically,
and then watch how the world pushes back.
Scientists use AI programs to design robots out of flexible LEGO like cubes.
These cubes act like blocky muscle, allowing the robots to move their bodies like caterpillars.
The AI designed robots learn by trial and error, adding and subtracting cubes,
and evolving it to more mobile forms, as the worst designs get eliminated.
In 2020, scientists discovered how to make robots walk.
Scientists used microsurgery to remove live skin stem cells from an African clawed frog,
and nudge them together in water.
The cells fused into a lump, the size of a sesame seed, and acted as an unit.
Skin cells have cilia, tiny hairs that typically hold a layer of protective mucus,
on the surface of an adult frog.
But these creations use their cilia like oars, roaring through their new world.
They navigated mazes, and even closed up wounds when injured.
Freed from their confined existence in a biological cubicle,
they became something new and made the best of their situation.
They definitely weren’t frogs, despite sharing the identical genomes.
Because the cells came from frogs of the genus Xenopus, they named it Xenobots.
In 2023, they showed similar feats could be achieved by pieces of another species:
Human lung cells.
Clumps of human cells self assembled and moved around in specific ways.
They named it anthrobots.
Xenobots and anthrobots are another sign that we need to rethink,
the way cognition plays out in the real world.
When we ask about a living thing:
why does it have the shape it has?
Why does it have the behaviour it has?
The standard answer is of course - evolution.
For eons it was selected for.
There have never been any xenobots.
There has never been any pressure to be a good xenobots.
So why do these things, do what they do, within 24 hours of finding themselves in the world?
It is possible that evolution does not produce specific solutions, to specific problems.
It produces problem solving machines.
Xenobots and anthrobots are quite limited in their capabilities.
They perhaps provide a window into how intelligence, might naturally scale up,
why individual units with certain goals and needs come together to collaborate.
Levin sees this innate tendency towards innovation, as one of the driving forces of evolution,
pushing the world towards a state of, as Charles Darwin might have put it,
endless forms most beautiful.
Levin hopes we will acknowledge that minds come in packages,
bearing little resemblance to our own, whether they are made of slime or silicon.
Recognising that kinship is the real promise of basal cognition.
We think we are the crown of creation.
We are beginning to realise that we have a lot more in common, with the blades of grass,
and the bacteria in our stomach, - that we are related at a really, really deep level.
It changes the entire paradigm of what it is to be a human being on this planet.
The very act of living is by default a cognitive state.
Every cell needs to be constantly evaluating its surroundings,
making decisions about what to let in, and what to keep out and planning its next steps.
Cognition didn’t arrive later in evolution.
Its what made life possible.
Everything we see that is alive, is doing this amazing thing.
If an aeroplane could do that, it would be bringing its own fuel and raw materials,
from the outside world, while manufacturing not just the components,
but also the machines it needs to make those components,
and doing repairs, - all while it is flying!
What we do is nothing short of a miracle.