Braitenberg Vehicles show lifelike behaviour emerging from direct sensor-to-motor coupling

An autonomous agent senses and acts on its environment on its own agenda, with no global coordinator; structure emerges from local interactions. Valentino Braitenberg’s Vehicles (1984) are the minimal illustration: Vehicle 1 wires one sensor directly to one motor, so a strong stimulus drives the motor fast and a weak one slow. Vehicle 2 has two sensor-motor pairs; wiring them straight (2a) versus crossed (2b) makes one flee a light and the other approach it, which we read as ‘cowardly’ versus ‘aggressive’. No internal state or memory is needed — the behaviour is entirely a product of the sensor-motor wiring and the environment. This is the foundational example that complex, seemingly intentional behaviour can arise from very simple local rules, the same principle behind flocking (Reynolds’s Boids) and cellular agents.

Examples

// Vehicle 2a: sensor value drives same-side motor (uncrossed) -> avoids light // Vehicle 2b: sensor value drives opposite-side motor (crossed) -> seeks light leftMotor = leftSensor; // 2a rightMotor = rightSensor; // vs leftMotor = rightSensor; // 2b rightMotor = leftSensor;

Assessment

Explain why crossing the sensor-motor connections turns a light-avoiding Vehicle 2a into a light-seeking Vehicle 2b; predict what Vehicle 1 does when its single sensor registers nothing.