Digest: Same senses, different minds in <i>Heliconius</i> butterflies

What neural changes underlie the evolution of novel behaviour? Does behavioural innovation require enhanced sensory input, or can it arise through reorganisation of existing neural circuits? Hodge et al. (2026) show that the enlarged mushroom bodies associated with specialised foraging in Heliconius butterflies reflect localised circuit restructuring, while peripheral sensory pathways remain largely conserved. These findings suggest that cognitive innovation can emerge through changes in integrative brain centres without expansion of sensory systems.