Figure 6.

Differential appetitive reversal learning paradigm in larval Drosophila. The larvae were trained and tested as in Figure 5, except that 1-octanol was used as the second odor (violet cloud) in all training trials in which n-amyl acetate (red cloud) was not presented. (A) The larvae were tested either (i) immediately after one-phase training, (ii) after training with reversed contingencies in the first and the second training phase, (iii) after omitting the first training phase, or (iv) after omitting the second training phase. Preference scores (PREF) reflect preference for n-amyl acetate (red cloud). (B) PI calculated from the preference scores in A. Positive and negative PIs indicate appetitive memory related to the first and the second training phase, respectively. The PIs after reversed-contingency training were less negative than when the first training phase was omitted, suggesting a persisting impact from the first training phase. In turn, after reversed-contingency training, the PIs were more negative than when the second training phase was omitted, suggesting behavior in accordance with the second training phase. The fact that the PI after reversed-contingency training were significantly negative and that the PIs were significantly positive when the second training phase was omitted confirms these respective conclusions. Sample sizes are given within the figure. * refers to MWU comparisons between groups, ^# refers to OSS comparisons to chance levels, that is, to zero (*^,# P < 0.05 corrected according to Bonferroni-Holm). Other details as in Figures 1–5.