It was mentioned in the introduction to this study that the different associations assumed to be made in the different training procedures - namely stimulus-reinforcer during classical conditioning and response-reinforcer during operant conditioning - might lead to different behavioral strategies to avoid the pattern orientation associated with heat. For instance, if the classically trained fly learned about the 'heatedness' of one of the pattern orientations, it might use the same behavioral repertoire to avoid this flight direction as is employed by the control group for spontaneous preference.
Conversely, operantly trained flies may have acquired a more effective (or at least different) way to avoid the heat during their training, selecting among many different behavioral strategies. In this case, the motor-output produced by those flies should be different from both the respective control-group and the classically conditioned group.
It is assumed - and data supporting this assumption is discussed below (3.3) - that torque spikes are the fly's primary behavior to adjust flight direction (Heisenberg and Wolf, 1979; Heisenberg and Wolf, 1984; Mayer et al. 1988; Heisenberg and Wolf, 1993). Therefore, all properties of the torque spikes are evaluated in this study: spike amplitude, spike duration, spike polarity, spike number, spike latency, interspike intervals etc.