I just finished reading On Intelligence. Aside from the expected atheist and evolutionist crap (I am Christian and I think Darwinian evolution is voodoo science) that permeates Jeff Hawkins' prose, I liked it very much. I am impressed by the level of understanding he conveys in the book. One thing in particular strikes me as being brilliant. Hawkins claims that the brain's cortical hierarchy is used for both pattern recognition and motor behavior. He tells us that low-level pattern detectors send motor commands directly to the motor cortex where they are relayed to the muscles via motor neurons. What makes sensorimotor behavior so powerful is that pattern detectors (and thus, motor effectors) are controlled by a complex knowledge hierarchy that also serves as a behavior selection mechanism.
The Holy Grail
People like Hawkins and Rodney Brooks (founder of iRobot and Rethink Robotics) understand that there is a tight connection between pattern detectors and motor effectors. Brooks revolutionized robotics when he introduced his subsumption architecture to the field in the 1980s. He insisted that sensory signals should undergo as little processing as possible on their way to motor effectors. Of course, old school AI researchers like Marvin Minsky had nothing but contempt for Brooks' approach but Brooks was right. For his part, Hawkins goes much further than Brooks by positing an actual neural mechanism for sensorimotor behavior. On page 107 of his book, he writes:
For me to physically move from my living room to my kitchen, all my brain has to do is mentally switch from the invariant representation of my living room to the invariant representation of my kitchen. This switch causes a complex unfolding of sequences. The process of generating the sequence of predictions of what I will see, feel, and hear while walking from the living room to the kitchen also generates the sequence of motor commands that makes me walk from my living room to my kitchen and move my eyes as I do so. Prediction and motor behavior work hand in hand as patterns flow down and up the cortical hierarchy. As strange as it sounds, when your own behavior is involved, your predictions not only precede sensation, they determine sensation. Thinking of going to the next pattern in a sequence causes a cascading prediction of what you should experience next. As the cascading prediction unfolds, it generates the motor commands necessary to fulfill the prediction. Thinking, predicting, and doing are all part of the same unfolding of sequences moving down the cortical hierarchy.This is pure freaking genius, in my opinion. I am truly impressed. But, unfortunately, Hawkins leaves it there. He doesn't explain how to achieve this holy grail. The reason, of course, is that he doesn't know how.
"Doing" by thinking, the parallel unfolding of perception and motor behavior, is the essence of what is called goal-oriented behavior. Goal-oriented behavior is the holy grail of robotics. It is built into the fabric of the cortex.
Blowing in the Wind
I agree with Hawkins that achieving goal-oriented behavior is the holy grail of robotics. A solution would solve a mountain of problems, and not just things like learning how to walk or how to use various appendages and actuators to interact intelligently with objects in the world. It would also give machines the ability to learn to understand and speak a natural language, read, write and do math, etc., just like humans. The question is, assuming one has a well-designed hierarchical memory, how does the system connect the pattern detectors to the motor effectors in order to generate goal-directed behavior? That is the holy grail.
OK. I am not saying what I am about to say in order to boast of my mental abilities or any such thing. In fact, I'm rather slow compared to people like Brooks and Hawkins. I cannot boast simply because I did not figure it out on my own. As I have said several times before, I consult an oracle. The oracle speaks in riddles and metaphors and says many mysterious things. I just interpret them the best I can. It so happens that this holy grail of robotics is precisely one of the things that the oracle explains. Here's what the oracle has to say on the matter:
Notwithstanding I have a few things against thee, because thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols.Shit! I done did it again. Excuse me while I ROTFLMAO. ... Alright. I need to compose myself. Whew! As you can see, the oracle has a great sense of humor. I've always had a weak spot for that fornicating ho, Jezebel. LOL. Seriously now, what I am trying to say is this. If you could correctly interpret the metaphors in the passage above, then you would know the secret of the holy grail of robotics.
Do I know the answer to the riddle? Yes, I do, and it is as simple as it is powerful. But that's all I am going to venture on this topic for now. The solution to the riddle must stay secret a little while longer. Sorry to leave y'all hanging like this. As the Bob Dylan song says, "the answer my friend is blowing in the wind, the answer is blowing in the wind." It's time for a beer.
By the way, if any of what I wrote above bothers you, then please don't read my stuff. It is not meant for you. I only write for kindred spirits, sorry.
Jeff Hawkins Is Close to Something Big