Figure 1.
Flies were conditioned in the presence of stimuli that could act as potential attractive cues. In the anemotaxis experiments, an air source was provided at the back of the chambers. A fly with a potential preference for the air source is represented, with the arrows suggesting movement toward that source (front and back refer to either end of the chamber). Training associated the chamber end with the air source with 41°C. In the phototaxis experiments, a light source was provided at the front of the chambers. Training associated the lit end with the aversive temperature of 41°C. In the gravitaxis experiments, chambers were shifted at 7.8° and 15.6o from the horizon. Training associated the higher end with the aversive temperature of 41°C. Controls for each of these cues were without the potentially attractive cue. A second set of controls used the nonaversive temperature of 24°C as the “training” temperature. No conditioning was expected in these control conditions, and provided information about the attractiveness of the cues presented.