What a maze-solving oil drop tells us of intelligence
2010 01 24

By Colin Barras | NewScientist.com


Dyed pink and doped with acid, the small, inanimate drop of oil is deposited at the entrance to the maze - and immediately sets off towards the exit. A few minutes later, it emerges at the other end.

No one would equate this apparently astonishing problem-solving with intelligence. But new theories on human intelligence and the brain suggest the simple molecular processes governing the oil droplet's apparently smart behaviour may be fundamentally similar to those that govern how we act.

A decade ago Toshiyuki Nakagaki, now at Hokkaido University in Sapporo, Japan, reported that the slime mould Physarum polycephalum could negotiate a maze to reach food at the exit. Boldly, his team wrote in Nature: "this implies that cellular materials can show a primitive intelligence".

Now Bartosz Grzybowski, a chemist at Northwestern University in Evanston, Illinois, has shown that a simple oil droplet floating on top of an aqueous solution can also navigate a complex maze - in this case to reach an acid-soaked lump of gel at the exit.



The droplet moves because the gel sets up a pH gradient within the maze. The acid changes the surface tension of the oil droplet, but because of the pH gradient, it affects opposite sides of the droplet unequally. The surface tension is different at the slightly more acidic "front" of the droplet than at the back. This difference is what is ultimately responsible for moving the droplet towards the maze's exit.


Obstacle course. On the left, a droplet moves toward the dashed box along the shortest path. On the right, the droplet goes astray at two locations but corrects its trajectory and ultimately finds the shortest path. CREDIT: ISTVAN LAGZI, BARTOSZ GRZYBOWSKI, ET AL., JACS

Nakagaki is unwilling to extend the notion of intelligence to the oil droplet. "It is nonsense for me to consider intelligence in non-living systems," he says. But Andy Clark, a philosopher at the University of Edinburgh, UK, suggests that this does not do Grzybowski's set-up justice. Much of biology boils down to chemistry, Clark points out. "The mere fact that it's just physical stuff doing what it does can't be a strike against the droplets," he says. "Whatever intelligence is, it can't be intelligent all the way down. It's just dumb stuff at the bottom."

So why does the dumb droplet appear to be moving in an intelligent way? The answer is all around us, says Clark. The aqueous environment surrounding the droplet is structured to such a high degree by the pH gradient that it makes the dumb droplet appear smart. "It's a neat demonstration of just how much problem-solving punch you can get from a minimal internal structure in a nicely enabling environment."

Humans rely on the same trick, says Clark. It forms the basis of the extended mind theory, which Clark and David Chalmers, now at the Australian National University in Canberra, proposed in the late 1990s. They say the division between mind and environment is less rigid than previously thought; the mind uses information within the environment as an extension of itself.

While a person can learn a route through a maze and then negotiate the maze by memory, a person would appear equally smart to an outsider if they simply followed signposts in the maze to reach the exit. "A smart person, like the droplets, is often smart due to canny combinations of internal and external structure," says Clark.

It's a powerful idea that is filtering into theories about artificial intelligence. Rolf Pfeifer at the University of Zurich in Switzerland is exploring how to "outsource" some of the cognitive load of artificially intelligent systems. He points out evidence that the way our knees absorb the energy of a jump is controlled by the material properties of the leg itself: the reactions happen too quickly to be controlled by the brain or even a reflex. Through careful choice of materials, Pfeifer is now applying that idea in his robot creations by designing body parts that are capable, to some degree, of autonomously reacting to their environment.

Karl Friston, a neuroscientist at University College London, goes further. He says the human brain and the oil droplet do share some fundamental attributes, in particular in the way they both respond to their environment.

This ties in with Bayesian brain theory, which pictures our brains as attempting to understand the world by observing the environment and making, then improving, predictions about what will happen next. Friston is working on a unified theory of the brain (New Scientist, 31 May 2008, p 30) that mathematically describes how the brain continually improves its predictions by observing its environment and minimising errors.

He sees "deep similarities" between his theory and the droplet's movement. As the droplet moves towards the exit it is moving towards a state of chemical equilibrium, where it has minimised its free energy.

Work on artificial neural networks has shown that the same principles apply to these networks: by minimising the difference between the predictions a network makes and what it actually senses happening, the network is also driven towards equilibrium. Friston is now showing how the equations that govern neural networks and thermodynamic systems apply to real brains.

The bottom line is that the "dumb" droplet is simply obeying fundamental principles. But because it is using exceptionally ordered information in the environment along the way, it moves "in an apparently purposeful way", Friston says.

None of this, of course, justifies calling Grzybowski's oil droplet "intelligent". But it does suggest that by highlighting the importance of the environment, his maze experiment may have hit on a fundamental connection between apparently intelligent behaviour at all levels: the ability to read and respond to environmental cues.

Article from: NewScientist.com



RedIce Radio:

Kevin Warwick - Artificial Intelligence & The Rise of the Machines in 2020

Aaron Franz - The Age of Transitions

aron Franz - The Age of Transitions Continued (Subscription)

John Lash - Artificial Technomania of the Archons (Subscription)

Jim Elvidge - Are we Living in a Simulation, a Programmed Reality?

Lynne McTaggart - The Intention Experiment



Related Articles
Blob intelligence is not unlike our own
'Intelligent' oil droplet navigates chemical maze (Video)
The Creation of Smarter Than Human Intelligence
Artificial brain '10 years away'
Artificial intelligence: The robots are coming but are we ready for them?
Artificial Intelligence Cracks 4,000-Year-Old Mystery
The effect of belief on intelligence
Psychology of Intelligence Analysis
Aubrey de Grey, Artificial Intelligence, Singularity, Longevity and the Holy Grail
Plants Recognize Their Siblings, Biologists Discover
Plants and Animals: Long-Lost Relatives?
Insects Use Plants Like A Telephone
Scientists "listen" to plants to find water pollution
Plant communication: Sagebrush engage in self-recognition and warn of danger


Latest News from our Front Page

Seven Points of Agreement Between Individuals
2014 10 02
In what follows, underlined words are my modifications to the original (cite given at the end) "Seven Points of Agreement Between Individuals" -- a binding contract entered into by individuals with other individuals so as to create a society within which individual sovereignty is upheld. These agreements are thought by the author of the book within which they appear to ...
If Someone Secretly Controlled What You Say, Would Anyone Notice?
2014 10 01
The subject enters a room in which a 12-year-old boy is seated. A 20-minute conversation ensues. The subject quizzes the boy about current events and other topics to get a sense of his intelligence and personality. But the boy is not what he appears to be. Unbeknownst to the subject, the boy is wearing a radio receiver in his ear, and ...
Obama has had accurate intelligence about ISIS since BEFORE the 2012 election, says administration insider
2014 10 01
‘President Barack Obama’s intelligence briefings have provided him with specific information since before he won re-election in 2012 about the growing threat of the terror group now known alternatively as ISIS and ISIL, an administration insider told MailOnline on Monday. ‘Unless someone very senior has been shredding the president’s daily briefings and telling him that the dog ate them, highly accurate ...
Can holding a magnet against your head help defeat depression?
2014 10 01
Former GP Sue Mildred suffered from crippling depression and anxiety for 20 years. On two occasions it was so severe that she ended up in hospital, and for 15 years she was unable to work. Sue, 51, has tried antidepressants, talking therapies and, out of desperation, even ECT (electro-convulsive therapy), where an electric current is passed through the brain. This did ...
Extremists to have Facebook and Twitter vetted by anti-terror police
2014 09 30
Theresa May to announce new Extremist Disruption Orders to strengthen counter-terrorism if the Tories win the next general election Extremists will have to get posts on Facebook and Twitter approved in advance by the police under sweeping rules planned by the Conservatives. They will also be barred from speaking at public events if they represent a threat to “the functioning of democracy”, ...
More News »