A Worm's Mind In a Lego Body

mikejuk writes The nematode worm Caenorhabditis elegans (C. elegans) is tiny and only has 302 neurons. These have been completely mapped, and one of the founders of the OpenWorm project, Timothy Busbice, has taken the connectome and implemented an object oriented neuron program. The neurons communicate by sending UDP packets across the network. The software works with sensors and effectors provided by a simple LEGO robot. The sensors are sampled every 100ms. For example, the sonar sensor on the robot is wired as the worm's nose. If anything comes within 20cm of the 'nose' then UDP packets are sent to the sensory neurons in the network. The motor neurons are wired up to the left and right motors of the robot. It is claimed that the robot behaved in ways that are similar to observed C. elegans. Stimulation of the nose stopped forward motion. Touching the anterior and posterior touch sensors made the robot move forward and back accordingly. Stimulating the food sensor made the robot move forward. The key point is that there was no programming or learning involved to create the behaviors. The connectome of the worm was mapped and implemented as a software system and the behaviors emerge. Is the robot a C. elegans in a different body or is it something quite new? Is it alive? These are questions for philosophers, but it does suggest that the ghost in the machine is just the machine. The important question is does it scale?

Comments

No programming?

[tomhath]

The key point is that there was no programming or learning involved to create the behaviors.

Yes, there was. The behaviors didn't just "emerge", they're coded into the robot.

Re:No programming?

[Kjella]

If you call copy-paste programming. They took an "executable", dumped it from the worm's brain, put it in a robot and found it acts like a worm. The behavior emerged through evolution and was encoded in the neurons by nature, not the researchers. If you could dump a human brain, put it in a robot and have it act like a human without ever "reverse engineering" it that would be most impressive.

Re:No programming?

[teslar]

The behavior emerged through evolution and was encoded in the neurons by nature

What has been implemented in this robot has nothing to do with biological neurons of C. elegans.

The robot uses integrate-and-fire neurons. The "signal" sent from pre- to postsynaptic neuron is an integer equal to the number of connection between the neurons in the real worm. If the sum of input exceeds a threshold, the neuron "fires" (sidenote: right here's a bit of programming: how did the threshold values get chosen?).

C. elegans neurons do not "fire" (they are not spiking neurons and lack Na+ channels) but use calcium-based analog signals.

The body does matter too. C elegans has muscles on either side that it contracts alternately to move in a sinusoidal fashion. Not wheels. C elegans locomotion does not work like wheeled locomotion.

So, yes, you are right, C elegans neurons encode behaviour appropriate for a C elegans body given the biology of the neurons available here. None of this, however, makes it into this robot. An abstraction of the connectome does (C elegans has both electrical and chemical synapses; that distinction seems to be lost here too) and that's it.

It is kinda cool that the connectome does seem to naturally implement some basic response patterns; but given that muscles have been replaced by wheels, I'm not sure how meaningful that actually is.

Does it scale?

[Anonymous Coward]

Try Duplo.

Memory mapping?

[Kevin Fishburne]

Emulating the connectivity and functionality of neurons is pretty awesome, but it would seem the next logical step would be to map and interpret how memories are stored and processed, as well as organ feedback (skin, smell, glands). What's really interesting about this is that it shows, at least to some degree, that a simple brain can be reproduced using mathematical relationships (programming) and "run" with a I/O feedback loop. As far as the philosophical stuff, I think eventually we'll be forced to accept that life is a type of machine and that the "ghost" is an illusion emerging from its complexity. Other than better neuroscience, the main thing holding us back is pride.

Re:This isn't about technological developments,

[linuxrocks123]

Instead of calling everyone around you an idiot, why don't you read the question again and consider again what is being asked.

Unless you have absolutely no ethical qualms about what Dr. Mengele did to his experimental subjects, the ethical questions raised by emulating a complete human brain are in no way trivial and in no way unimportant. Right now, we reformat computers, turn them off, turn them on, and don't and don't have to care at all about what they "want" or about treating them with any kind of respect. If we successfully simulate a human brain to the point where it can "think" and has humanlike "emotions", deleting that neural net file might be fairly considered murder. No, really. If you can talk to the thing and it can talk back, and it looks, talks, and acts like a human ... it's a duck. Sorry, human.

Now, we are nowhere near having that capability. We don't have to worry about that question now. But it's a very interesting question to think about, because thinking about it can grant insights into what it means for something to be sentient or human in the first place.