Now let’s take off Turing’s hat and put on Searle’s. We immediately turn on the lights and pick up the dang Tadro. What is this thing? What’s inside? We look inside the plastic bowl that serves as Tadro’s hull and see a small, black, rectangular box with what looks like a big, engorged tick sticking on it (sorry, I live in upstate New York, one of the world’s hotspots for blood-sucking ticks and the diseases that they spread; I see them everywhere …). That “tick” is actually a capacitor, a common element of electronic circuits, and it is interspersed with other bug-sized bits of like-minded paraphernalia: rectangular silver-legged spiders (integrated circuits), columns of red and green “ants” (indicator lights), and the long tracks of tiny potholes left by centipedes (input and output connections for wire). This palm-size block of electronics is a microcontroller,[59] a fully functioning computer (a central processing unit, or CPU) with its own power supply, memory, and systems to operate motors and sensors.
Is this microcontroller a brain? Doesn’t look like it. It’s a computer with the ability to interact with motors and sensors. You can program the microcontroller to tell the tail motor which way to turn depending on the light intensity hitting the photoresistor that serves as the eyespot. The program is not the brain, either. It is written in a programming language called Interactive C, which was created especially for controlling mobile robots.[60] We can call up the original Interactive C program that Adam Lammert wrote for Tadro2 and see for ourselves that there appears to be nothing brain-like about it (Figure 5.1): a bunch of words and type-written symbols, a regularity of symbol patterning that indicates a syntax, and words like “if” and “else,” which if used in the same way as those words are in English, may indicate something about the program making decisions. Even if that naïve description sounds brain-like because of its references to language, keep in mind that Searle would argue that the Tadro program is not, in and of itself, intelligent; the program doesn’t know what it is doing. It just is a deaf, dumb, blind kid telling the hardware how to play pinball with electrons.
FIGURE 5.1. Making Tadro go. This is the complete Tadro2 program, written in computer language called “Interactive C” by Adam Lammert for his senior thesis in cognitive science at Vassar College. The program ran on a HandyBoard microcontroller, taking input from the single sensor, a photoresistor acting as an eyespot, and turning it into a value for the variable, “beta,” that told the always-flapping tail which way to turn. This sensor-motor interaction, shown in the gray box, is always changing because the new turning command alters the heading of the Tadro that, in turn, alters the light hitting the sensor. Thus, the whole system—program, microcontroller, sensor, motor, body, and environment—can be thought of as continually calculating an answer to this question: what’s the angle of my tail?
See the problem here? If we define intelligence by what Tadro does, then it clearly has skill, the know-how to detect and follow a light source. Because Tadro’s light-following ability depends on its propulsion, maneuverability, and the sensitivity of its photoresistor, its body is clearly important. You can get a sense for the importance of having a body to help you think next time you put together a difficult jigsaw puzzle: you simply can’t solve the puzzle unless you allow yourself to pick pieces up, rotate them in different directions, and try to align and engage the pieces.
If you don’t believe me, try this: have a friend spread out pieces of a jigsaw puzzle on the table. Rule 1: You are not allowed to touch the pieces. Rule 2: You are not allowed to move from where you sit or stand. Rule 3: Using only your voice (not gestures or written instructions), tell your friend how to assemble the puzzle, piece by piece. Note that you can’t just say, “Put the puzzle together.” No how. You’ve got to give low-level instructions like, “Take the piece right in front of you and move it next to the piece right over there.” Rule 4: All your friend can do is follow your rules. These rules turn out to be what we call motor commands when we talk about neural circuits. You’ll soon be impressed—unless you have a very simple puzzle—with just how much intelligence depends on your movements and your physical manipulation of the world. That movement-based intelligence begins with what Alva Noë, associate professor at the Institute for Cognitive and Brain Sciences at the University of California at Berkeley, calls “enactive perception.”[61] Enactive perception in robots combining active vision and feature selection helps simplify vision-based behavior, as shown in experiments by Dario Floreano, director of the Laboratory of Intelligent Systems at the École Polytechnique Fédérale de Lausanne in Switzerland and one of the founders of the field of evolutionary robotics.[62]
Adam and I give Tadro credit for having the know-how of enactive perception: wandering around, exploring its space, detecting a light gradient (if it’s there), moving toward the source of the light, and orbiting around that source. If you had to tell your puzzle-helping friend to do the same, step by literal step, I bet you’d learn to respect our piece of embodied intelligence!
With the hats of both Turing and Searle off, let’s baldly go where no one has gone before: into Tadro’s embodied-brain. I say “embodied-brain” as a single-word construct here because I want to reference a shift in perspective for neuroscientists promoted by Professor Barry Trimmer, neuroscientist and director of Tuft University’s Biomimetic Devices Laboratory. I visited his lab recently, and as we were discussing how animals create behavior, he said, “Every brain has a body.” Sounds straightforward. But wait—that seemingly self-evident phrase, familiar to many within the fields of philosophy of mind,[63] ecological psychology,[64] grounded cognition,[65] and embodied artificial intelligence,[66] rings wrong-headed to neuroscientists who’ve specialized in the brain’s molecular channels, neurotransmitter systems, control circuits, or functional regionalization. Why?
Most of us have been trained to think of the brain as the control center, the place on the anatomical map where all of the sensor inputs are read and discussed. We know that the brain is “in control of behavior” because damage to the brain alters our thinking: damage to Phineas Gage’s frontal lobes compromised his ability to process emotions and make rational decisions.[67] We’ve seen cool functional-MRI videos of Oliver Sack’s brain responding differently to music by Bach and Beethoven, in concert with his reported subjective experience.[68] After much thinking, our subjective, first-person experience of being an autonomous agent tells us that the control center creates a plan that is sent out to the soldiers in the field, the muscles that put the plan into action.
As neuroscientist Joaquin Fuster of the UCLA Neuropsychiatric Institute more formally states, “All forms of adaptive behavior require the processing of streams of sensory information and their transduction into series of goal-directed actions.”[69] Fuster reviews experimental work that shows how goal-directed plans activate the prefrontal and premotor regions of the brain. In this view, planning is a central, if not the central, function of our brains as thinking machines (Figure 5.2).
59
The particular microcontroller we used for Tadros 2 to 4 was a HandyBoard, invented by Fred Martin at MIT (see \en.wikipedia.org/wiki/Handyboard for a great picture and a useful overview). The original Tadro1 had a completely analog electronic brain.
60
The software that runs on the Handyboard, Interactive C, was originally developed for LEGO Robotics competitions. Two versions of Interactive C are available, one by Newton Labs (www.newtonlabs.com/ic/) and the other by the KISS Institute (www.botball.org/ic).
62
For a review of the work of Floreano and his colleagues on this topic, see Mototaka Suzuki and Dario Floreano, “Enactive Robot Vision,”
63
George Lakoff and Mark Johnson,
64
Ecological psychology was created by J. J. Gibson. Here’s a great place to start: J. J. Gibson, “Visually Controlled Locomotion and Visual Orientation in Animals,”
65
Lawrence W. Barsalou, “Grounded Cognition,”
66
Once again I refer you to Pfeifer and Scheier’s excellent book,
67
Even if you have heard about Phineas Gage before, you should read this fascinating paper: H. Damasio, T. Grabowski, R. Frank, A. M. Galaburda, and A. R. Damasio, “The Return of Phineas Gage: Clues about the Brain from the Skull of a Famous Patient,”
68
NOVA, “Musical Minds,” www.pbs.org/wgbh/nova/musicminds/. A video fMRI of Sack’s brain listening to music can be found at www.pbs.org/wgbh/nova/musicminds/extra.html.
69
J. M. Fuster, “Upper Processing Stages of the Perception-Action Cycle,”