Fig. 6. The ability of intact (sham control) lobsters (A) and aesthetasc-ablated lobsters (B) to learn a discrimination conditioning task and to discriminate between binary mixtures of AMP+taurine with the same total concentration (1 mmol l^–1) but at different blend ratios. The discrimination conditioning paradigm is described in Table 3. The aversively conditioned odorant (CS+) was the 99.9:0.1 blend ratio, and the conditioned ‘safe’ odorants (CS–) were the blend ratios 99:1, 90:10 and 50:50. Values are means + S.E.M. *Search responses significantly different in unconditioned and conditioned lobsters (planned comparisons one-way ANOVA, P<0.05); Search responses significantly larger than those elicited by the aversively conditioned blend ratio 99.9:0.1 (CS+) in conditioned lobsters (planned-comparisons one-way ANOVA, P<0.05). For the planned comparisons, critical values for a 5 % experiment-wise error rate were determined by the sequential Bonferroni test using the Dunn–idák method (Sokal and Rohlf, 1998). Search responses of conditioned lobsters to oyster extract (OE) after the post-conditioning phase are also shown. In both intact and aesthetasc-ablated lobsters, search responses to oyster extract before and after conditioning were not significantly different (P<0.05, t-test for dependent samples). For a description of search responses and calculation of the standardized search responses relative to the responses to oyster extract in the preconditioning phase, see Materials and methods.