Figure 1.

Patterns presented, and outline of the learning regimes. (a) Scent training patterns, where empty circles denote unscented wells containing mineral oil, and filled blue circles denote scented wells containing the diluted peppermint oil. (b) Visual marker test patterns. (c) Visual training patterns: note that eight of the holes on each disc are lined with a green circle that subtly differs in shade to the background—the positioning of these visual stimulus circles correspond to the eight wells on each flower in (a) that received a scent stimulus. The visual discs were placed on top of the discs containing filled wells, with holes (white circles) aligned with the wells. In (a–c), a drinking cup was placed in the centre of the topmost disc. (d) Sketch of the scent pattern learning trials, and the corresponding visual marker test (presented in figures 2 and 3), where the cross (i) or circle (ii) was the rewarding stimulus. (Note that the spots denoting scent positions have been enlarged for clarity, and do not represent any physical enlargement in the experimental apparatus.) (e) Sketch of the multimodal stimulus learning tests (presented in figure 4), where either the scent and visual patterns corresponded so that scented wells were marked (i and ii), or where the rewarded scented pattern corresponded to the non-rewarded visual pattern and vice versa (iii and iv), or where bees learnt a visual pattern without a corresponding scent pattern (v and vi). See also table 1 for details of training regimes (i–vi).