Bio-Inspired Artificial Intelligence: Theories, Methods, and Technologies by Shane Dawson

Author:Shane Dawson
Language: eng
Format: mobi, epub, pdf
ISBN: 9781476791548
Publisher: Atria/Keywords Press
Published: 2015-02-10T00:00:00+00:00

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Behavioral Systems

Figure 6.1

The robots devised by Grey Walter and built with the assistance of Bunny

Warren in Bristol, England. The motor system of the robot was like a tricycle where

the front wheel was actuated by motors for regulating speed and steering. The robot

shell hung from a pole and came into contact with internal sensors whenever an

obstacle was encountered, thus functioning like a touch sensor. A photoreceptor

mounted on a rotating head was used to measure light intensity while scanning the

environment. The photograph shows a replica built by Owen Holland. Image cour-

tesy of the Intelligent Autonomous Systems lab, University of West England at Bristol.

In contrast to that approach, in the early 1950s Grey Walter built a series

of mobile robots to demonstrate that complex and purpose-driven behavior

could emerge from a set of simple and interconnected neuron-like devices

embodied in a situated organism (Walter 1950, 1951). Grey Walter, who is

now considered the creator of the first autonomous robots (Freeman 2003),

was trained as a neurophysiologist and electrical engineer. His robots were

also called “turtles” because of their shelled body and relatively low speed.

The electronics were composed only of analog devices (two valves, two ca-

pacitors, and two mechanical relays) and Walter insisted on the importance

of using analog elements instead of the digital computation embraced by

mainstream artificial intelligence. Owen Holland recently reconstructed the

robots from original pieces and circuit diagrams (figure 6.1). He showed that

these robots displayed complex and partially unpredictable behaviors such

as exploration, negative and positive tropism, discrimination, adaptation to

changing environments, and behavioral stabilization (Holland 2003).

Walter’s work attracted the attention of the media at that time, but did not

have an immediate impact on cognitive science and artificial intelligence.

6.2

Behavior in Artificial Intelligence

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Figure 6.2

Two Braitenberg vehicles: vehicle A is repulsed by light and vehicle B is

attracted. Reproduced from Braitenberg (1984).

Thirty years later, the neuroscientist Braitenberg (1984) published a book-

let describing a series of imaginary vehicles with simple wiring of sensors

and motors inspired by the anatomical and physiological principles of ner-

vous systems, such as symmetry, cross-lateral connection, excitation and in-

hibition, time-delayed activity, and nonlinear dynamics (figure 6.2). When

placed in an environment, Braitenberg’s vehicles displayed a range of com-

plex behaviors that an external observer might have labeled as aggression,

love, fear, logic, foresight, egotism, and free will. He even described an imag-

inary experiment with artificial evolution of these vehicles.

Braitenberg’s vehicles were intended to convey two major messages. The

first message was that much of the complexity observed in behavioral sys-

tems stemmed from the interaction with the environment rather than from

the complexity of the brain, similar to what Grey Walter intended to show

with his mechanical turtles. The second message was the law of uphill anal-

ysis and downhill invention: “When we analyze a mechanism, we tend to

overestimate its complexity. In the uphill process of analysis, a given de-

gree of complexity offers more resistance to the workings of our mind than it

would if we encountered it downhill, in the process of invention” (Braiten-

berg 1984, p.20). In other words, he argued that neuroscience and cognitive

science could gain considerably by combining the analysis of living brains

with the construction (synthesis) of embodied and behavioral circuits.

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