Figure 1.

Two-armed bandit experimental set-up for Physarum polycephalum. Cell biomass was placed in the centre (yellow box). White boxes indicate blank agar sites (non-rewarding), brown boxes indicate oat-agar food sites (rewarding). Agar sites were 1 mm in diameter. The first site on either arm was always a 5% oat-agar food site, to ensure the cell initialized exploration on both arms. Pictured here are the (a) 4e versus 8e treatment, where the LQ arm has evenly distributed reward sites, and the HQ arm has 8 evenly distributed reward sites, and (b) 4r versus 8r treatment, where the reward sites were distributed randomly. For graphic representations of other tested distributions, see the electronic supplementary material, figure S1. (Online version in colour.)