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Mind, Body, World- Foundations of Cognitive Science, 2013a

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obot has stopped moving, and two are light sensors that are used to attract the<br />

robot to locations <strong>of</strong> bright illumination. The sense-act reflexes <strong>of</strong> antiSLAM were<br />

not evolved but were instead created using the subsumption architecture.<br />

The lowest level <strong>of</strong> processing in antiSLAM is “drive,” which essentially uses the<br />

outputs <strong>of</strong> the ultrasonic sensors to control motor speed. The closer to an obstacle a<br />

sensor gets, the slower is the speed <strong>of</strong> the one motor that the sensor helps to control.<br />

The next level is “escape.” When both rotation sensors are signaling that the robot is<br />

stationary (i.e., stopped by an obstacle detected by both sensors), the robot executes<br />

a turn to point itself in a different direction. The next level up is “wall following”:<br />

motor speed is manipulated in such a way that the robot has a strong bias to keep<br />

closer to a wall on the right than to a wall on the left. The highest level is “feature,”<br />

which uses two light sensors to contribute to motor speed in such a way that it<br />

approaches areas <strong>of</strong> brighter light.<br />

AntiSLAM performs complex, lifelike exploratory behaviour when placed<br />

in general environments. It follows walls, steers itself around obstacles, explores<br />

regions <strong>of</strong> brighter light, and turns around and escapes when it finds itself stopped<br />

in a corner or in front <strong>of</strong> a large obstacle.<br />

When placed in a reorientation task arena, antiSLAM generates behaviours<br />

that give it the illusion <strong>of</strong> representing geometric and feature cues (Dawson,<br />

Dupuis, & Wilson, 2010). It follows walls in a rectangular arena, slowing to a halt<br />

when enters a corner. It then initiates a turning routine to exit the corner and<br />

continue exploring. Its light sensors permit it to reliably find a target location<br />

that is associated with particular geometric and local features. When local features<br />

are removed, it navigates the arena using geometric cues only, and it produces<br />

rotational errors. When local features are moved (i.e., an incorrect corner<br />

is illuminated), its choice <strong>of</strong> locations from a variety <strong>of</strong> starting points mimics the<br />

same combination <strong>of</strong> geometric and feature cues demonstrated in experiments<br />

with animals. In short, it produces some <strong>of</strong> the key features <strong>of</strong> the reorientation<br />

task—however, it does so without creating a cognitive map, and even without<br />

representing a goal. Furthermore, observations <strong>of</strong> antiSLAM’s reorientation task<br />

behaviour indicated that a crucial behavioural measure, the path taken by an agent<br />

as it moves through the arena, is critical. Such paths are rarely reported in studies<br />

<strong>of</strong> reorientation.<br />

The reorienting robots discussed above are fairly recent descendants <strong>of</strong> Grey<br />

Walter’s (1963) Tortoises, but their more ancient ancestors are the eighteenthcentury<br />

life-mimicking, clockwork automata (Wood, 2002). These devices brought<br />

into sharp focus the philosophical issues concerning the comparison <strong>of</strong> man and<br />

machine that was central to Cartesian philosophy (Grenville, 2001; Wood, 2002).<br />

Religious tensions concerning the mechanistic nature <strong>of</strong> man, and the spiritual<br />

nature <strong>of</strong> clockwork automata, were soothed by dualism: automata and animals<br />

Elements <strong>of</strong> Embodied <strong>Cognitive</strong> <strong>Science</strong> 243

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