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The Experiments

The Standard Experiment

In this paradigm the flight simulator establishes normal negative feedback between angular velocity of the arena and yaw torque (closed loop) throughout the experiment. This permits the animal to establish optomotor balance and to adjust certain flight directions with respect to the four T-shaped patterns on the walls of the cylindrical arena (Flight-Simulator mode). During training the fly is punished by an infrared light beam (input 6.9V), whenever one of the two pattern types is in the frontal quadrant of the visual field. The fly can control the appearance of the reinforcer by its choice of angular pattern position. During test, the heat source is switched off.
Each experiment lasts 9x2min (periods no. 1 through 9). After 2x2min. of unreinforced flight (pre-test, t1), a training period of another 2x2min. is introduced; after the following 2min. test, the 2x2min. training is repeated. The experiment is concluded by a 2x2min. test-phase (t2). At the beginning of each test-period the arena is rotated at high velocity to a random angular position.
A group of control-flies was subjected to the same experimental regime except for the reinforcement.

Classical Conditioning

In this paradigm, the flight simulator mode is interrupted (open loop) during training and the panorama is kept stationary with one pattern orientation in front of the fly: the fly's behavior cannot interfere with stimulus presentations. After 3s the panorama is rotated by 90° in 220ms, thus bringing the other pattern orientation into the frontal position. One of the two orientations is made contiguous with the reinforcer (input 5.3V). In the test periods the apparatus is switched to the flight simulator mode, and the animal's choice of angular pattern position is recorded without reinforcement.
The experimental regime is identical to the standard experiment and consists 9 periods of 2 minutes length (periods no. 1 through 9). After 2 periods of unreinforced closed-loop flight (pre-test, t1), two training period of 2min. are introduced; after the following 2min. test, the 2x2min. training is repeated. The experiment is concluded by a 2x2min. test-phase (t2). At the beginning of each test-period the arena is rotated at high velocity to a random angular position.
Again the control group received the same treatment, but was spared the reinforcement.

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